The URL can be used to link to this page

2021-June Coral Mountain Resort Draft EIR - Appendix J.3 - Master Hydrology Report CORAL MOUNTAIN RESORT DRAFT EIR SCH# 2021020310 TECHNICAL APPENDICES Master Hydrology Report Appendix J.3 June 2021 For Property Located In A Portion of Sections 27 & 28, Township 6 South, Range 7 East, SBM La Quinta, California CORAL MOUNTAIN RESORT Specific Plan January, 2021 Prepared for: CM Wave Development, L.L.C. 2440 Junction Place, Suite 200 Boulder, CO 80301 JN: 2553 ` MASTER PLAN HYDROLOGY REPORT For Property Located In A Portion of Sections 27 & 28, Township 6 South, Range 7 East, SBM La Quinta, California CORAL MOUNTAIN RESORT Specific Plan January, 2021 Prepared for: CM Wave Development, L.L.C. 2440 Junction Place, Suite 200 Boulder, CO 80301 JN: 2553 ` MASTER PLAN HYDROLOGY REPORT Coral Mountain Master Plan Hydrology Report TABLE OF CONTENTS PROJECT DESCRIPTION & LOCATION ........................................................................... 1 EXISTING SITE CONDITIONS ........................................................................................ 1 Flood Rate Map ..................................................................................................................1 Existing Topography ...........................................................................................................1 PROPOSED FLOOD CONTROL REQUIREMENTS ............................................................ 1 HYDROLOGY ANALYSIS DESIGN CRITERIA .................................................................... 1 Hydrologic Soil Group .........................................................................................................1 Antecedent Moisture Condition ...........................................................................................2 Land Use Classifications and Runoff Index Numbers .............................................................2 Precipitation Frequency Estimates .......................................................................................2 Site Infiltration ...................................................................................................................2 Proposed Land Use Summaries ............................................................................................3 SUMMARY of SYNTHETIC UNIT (SHORTCUT METHOD) ANALYSES ................................ 3 Drainage Area ‘A’ ...............................................................................................................3 Drainage Area ‘B’ ...............................................................................................................3 Drainage Areas ‘C’ & ‘F’ ......................................................................................................3 Drainage Area ‘D’ ...............................................................................................................3 Drainage Area ‘E’................................................................................................................3 Drainage Area ‘G’ ...............................................................................................................3 Drainage Area ‘H’ ...............................................................................................................4 Drainage Area ‘I’ ................................................................................................................4 Drainage Area ‘Off-Site North’ ............................................................................................4 Drainage Area ‘Off-Site South’ ............................................................................................4 PRELIMINARY WQMP ANALYSES ................................................................................ 4 RESULTS AND CONCLUSIONS ...................................................................................... 4 LIST OF APPENDICES A. RIVERSIDE COUNTY TLMA VICINITY MAP B. NFIP FLOOD INSURANCE RATE MAP C. USDA NCSS HYDROLOGIC SOILS MAP D. NOAA ATLAS 14 & RCFCD REFERENCE PLATES E. LAND USE WORKSHEETS F. RCFCD SYNTHETIC UNIT HYDROGRAPH WORKSHEETS G. RIVERSIDE COUNTY WHITEWATER RIVER REGION WQMP WORKSHEETS H. HYDROLOGY EXHIBITS Coral Mountain Master Plan Hydrology Report 1 PROJECT DESCRIPTION & LOCATION The project is proposed to consist of residential structures, a multi -story hotel complex, a wave lagoon and various outdoor amenities. The project site comprises approximately 377 acres with an additional 75 acres of offsite tributary area. The subject property is located on the southwest corner of Avenue 58 and Madison Street in the City of La Quinta and is situated in a portion of Sections 27 & 28, Township 6 South, Range 7 East, SBM. Existing dikes 2 & 4 along with the Coral Mountains border the prop erty to the west and south. A vicinity map obtained from the Riverside TLMA website is included as Appendix A. EXISTING SITE CONDITIONS Flood Rate Map The proposed area is covered by FIRM Panel Number 06065C 2900G, effective date of August 28, 2008, which indicates the subject property lies within Zone X (Shaded), defined as “Areas of 0.2% annual chance flood; areas of 1% annual chance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by levees from 1% annual chance flood. Insurance purchase is not required in these areas.” Refer to the attached NFIP Flood Insurance Rate Map in Appendix B. Existing Topography The property is generally vacant and undeveloped with CVWD irrigation mains, n umerous dirt road and hiking trails. Various desert vegetation is found throughout the site. The site is bounded to the east by Madison Street, to the north by 58th Avenue, existing levees and the Coral Mountains to the west and south, and 60th Avenue to the south. Groundwater was encountered at a depth of 47 feet for two of the borings. Site drainage appears to be controlled via sheet flow and surface infiltration generally from west to east. PROPOSED FLOOD CONTROL REQUIREMENTS The purpose of this report is to provide master plan basin analyses for the subject property. The drainage requirements for this project fall under the jurisdiction of the City of La Quinta. Storm flows are conveyed through the site via street flow to localized low points. All proposed pad elevations are set a minimum of 1- foot above the high-side street elevation. HYDROLOGY ANALYSIS DESIGN CRITERIA Storm runoff volumes for the 100-year event were obtained utilizing the Synthetic Unit Hydrograph as described in the RCFC&WCD Hydrology Manual. The hydrologic data used for the calculations are as follows: Hydrologic Soil Group The existing soil is categorized primarily as hydrologic soil groups “A” and “B” for the majority of the subject property with soil group “D” being assigned to the Coral Mountain rock out-cropping as shown per the attached National Cooperative Soil Survey exhibits in Appendix C. For the purposes of this report, Soil Group ‘B’ was assigned to the analyses with the exception of the rock out-cropping. Soil Group ‘B’ is defined by RCFCD as – “soils having moderate infiltration rates when thoroughly wetted and consisting chiefly of moderately deep to deep, moderately well to well drained soils with moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission”. Soil Group ‘D’ is defined by RCFCD as – “soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrin k-swell potential, soils that have a high- water table, soils that have a claypan or clay layer at or near the surface and soils that are shallow over nearly impervious material”. Coral Mountain Master Plan Hydrology Report 2 Antecedent Moisture Condition AMC II – Moderate runoff potential, an intermediate condition. Per RCFC & WCD Hydrology Manual (Dated: April 1978): “For the purposes of design hydrology using District methods, AMC II should normally be assumed for both the 10-year and 100-year frequency storm”. Land Use Classifications and Runoff Index Numbers Runoff Index Numbers were obtained from RCFCD Plates E6.1, E6.2 and E6.3 are summarized below: Commercial or Residential Landscaping (Soil Group B) 56 Rock Out-cropping (Soil Group D) 93 Existing Open Brush – Poor 76 Percent of Impervious Cover (RCFCD Plate E-6.3): Rock Out-cropping 5% Existing Open Brush – Poor Condition 5% Impervious Areas (Buildings, Pavement, Hardscape) 100% Water Features 100% Commercial Areas 90% SFR – Low Density 30% SFR – Medium Density 40% SFR – High Density 50% Open Space (Landscaping & Retention Basins) 10% Low Loss Rates: 85% Precipitation Frequency Estimates Precipitation depths were obtained from NOAA Atlas 14: 2 Year - 1 Hour Precipitation: 0.358 inches 10 Year – 1 Hour Precipitation: 0.711 inches 10 Year –3 Hour Precipitation: 1.06 inches 10 Year – 6 Hour Precipitation: 1.36 inches 10 Year – 24 Hour Precipitation: 2.23 inches 100 Year – 1 Hour Precipitation: 1.44 inches 100 Year – 3 Hour Precipitation: 2.14 inches 100 Year - 6 Hour Precipitation 2.76 inches 100 Year – 24 Hour Precipitation 4.41 inches Slope of Intensity Duration Curve: 0.52 See Appendix D for the NOAA Atlas 14 Point Precipitation Frequency Estimates and respective RCFCD Plates. Site Infiltration No percolation tests have been performed at the current time, therefore, for the purposes of this report a design percolation rate of 1 in/hr was used in the basin sizing calculations. Prior to the final design submittal, percolation tests will be performed, and should the 1 inch/hour rate not be achieved, Maxwell drywells will be proposed to de-water the basins within the required time period as specified by Riverside County BMP requirements. Coral Mountain Master Plan Hydrology Report 3 Proposed Land Use Summaries Land uses for each of the drainage areas were analyzed based on the preliminary site plan. In addition, a reconciliation was performed to verify the hydrologic boundary corresponds to the existing property boundary accounting for any differences. Land use worksheets are included in Appendix E. SUMMARY of SYNTHETIC UNIT (SHORTCUT METHOD) ANALYSES The proposed retention basins for the associated drainage areas were sized to retain the 100-year controlling storm event flood volumes and were analyzed utilizing the RCFCD Synthetic Unit (Shortcut Method). Per the manual, for areas of less than 100 – 200 acres, and lag times less than 7 – 8 minutes, the shortcut method is applicable. This method assumes that in a small watershed, response time to effective rainfall is very short. Therefore, runoff rates for a given period of time can be assumed to be directly proportional to effective rain. This method yields only approximate results (on the conservative side) and should be used only for watersheds meeting the criteria noted above. It should be noted that the peak flow for the 1-hour storm is not necessarily representative for peak flow. Per RCFCD, peak discharges from the 3-hour storm should normally compare well with rational peaks. The synthetic unit worksheets are included in Appendix F and are summarized on sheets 1 and 2 of the hydrology exhibits in Appendix H. Drainage Area ‘A’ This area is located on the westerly portion of the project and consists primarily of Dike Number 2, the Coral Mountains, a portion of Dike Number 4, the south-westerly portion of Planning Area IX and Planning Area X . Storm runoff (approximately 18.4 acre-feet) from this drainage sub-area is directed to the wave lagoon which provides over 69 acre-feet of retention. Shallow basins are proposed to retain 10-year storm flows from drainage areas ‘A1’ & ‘A3’. During the final design process, once a more detailed land plan is provided, first flush storm flows from drainage area ‘A2’ will be captured and conveyed to an underground storage area prior to being discharged into the lagoon. Drainage Area ‘B’ Storm runoff of 4.2 acre-feet from this drainage area will be retained within the proposed lake, which provides storage of approximately 6.7 acre-feet. Drainage Areas ‘C’ & ‘F’ Storm runoff from these drainage areas will be conveyed to and retained in a retention basin located in Drainage Area ‘F’. Drainage Area ‘F’ is a future low density planning area. The total flood volume is 4.8 acre- feet with 5.1 acre-feet of storage provided. Drainage Area ‘D’ Storm runoff of approximately 3.1 acre-feet for this drainage area will be conveyed to and retained in the proposed lake located within the “Farm”. The lake provides approximately 3.8 acre-feet of storage. Drainage Area ‘E’ Storm runoff of approximately 5.7 acre-feet for this drainage area will be conveyed to and retained in a large basin located in along the southerly portion of Planning Area VIII (Area 5). The basin provides storage of roughly 27.9 acre-feet. This basin will also provide a discharge location for the lagoon. Drainage Area ‘G’ This area is a future low-density residential development. Flood volume of 3.2 acre feet will be retained in a retention basin providing 3.4 acre-feet of storage. Coral Mountain Master Plan Hydrology Report 4 Drainage Area ‘H’ This area is a future commercial development. Flood volume of 1.1 acre-feet will be contained in two retention basins providing 1.4 acre-feet of storage. Drainage Area ‘I’ This area is a future low-density residential development. Once developed it is anticipated approximately 4.7 acre-feet of retention will be required, which will be contained in a retention basin providing 5.4 acre-feet of storage. Drainage Area ‘Off-Site North’ This area consists of the south half of Avenue 58 and the northerly west half of Madison Street. The storm flows are captured by an existing catch basin and discharged into an existing basin which will r emain when Drainage Area ‘I’ is developed. The existing basin provides 2.9 acre-feet of storage to contain the 1.3 acre-feet of flood volume. Drainage Area ‘Off-Site South’ This area consists of the north half of Avenue 60 and the southerly west half of Madison Street. The storm flows are captured by an existing catch basin and discharged into an exis ting basin which will remain when Drainage Area ‘E’ is developed. The existing basin provides 5.0 acre-feet of storage to contain the 0.9 acre- feet of flood volume. PRELIMINARY WQMP ANALYSES Preliminary design volume and flow for BMP measures were based on Worksheets 1 and 2 from the Riverside County – Whitewater River Region Water Quality Management Plan. Impervious area for the drainage sub - areas are derived from the preliminary land use worksheets. A summary of the BMP results is presented on sheet 1 of the Hydrology Exhibits in Appendix H with the worksheets being included as Appendix G. RESULTS AND CONCLUSIONS As the above narrative and appendices confirm, the proposed retention basins are sufficiently sized to contain the flood volume from the controlling 100-year storm. During the final design process, a more detailed hydrologic report will be submitted to the City for review and approval. Coral Mountain Master Plan Hydrology Report Appendix A Riverside County TLMA Vicinity Map *IMPORTANT* Maps and data are to be used for reference purposes only. Map features are approximate, and are not necessarily accurate to surveying or engineering standards. The County of Riverside makes no warranty or guarantee as to the content (the source is often third party), accuracy, timeliness, or completeness of any of the data provided, and assumes no legal responsibility for the information contained on this map. Any use of this product with respect to accuracy and precision shall be the sole responsibility of the user. © Riverside County GIS Legend THE WAVE Latitude: 33.6202 Longitude: -116.2562 Notes REPORT PRINTED ON...9/18/2019 9:08:13 AM MSA Job No. 2553 0 3,0091, 505 Feet Blueline Streams Survey City Areas World Street Map Coral Mountain Master Plan Hydrology Report Appendix B NFIP Flood Insurance Rate Map USGS The National Map: Orthoimagery. Data refreshed April, 2019. National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü116°15'18.16"W 33°36'49.57"N 116°14'40.70"W 33°36'19.61"N SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOODHAZARD AREAS Without Base Flood Elevation (BFE)Zone A, V, A99With BFE or Depth Zone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areasof 1% annual chance flood with averagedepth less than one foot or with drainageareas of less than one square mile Zone X Future Conditions 1% AnnualChance Flood Hazard Zone XArea with Reduced Flood Risk due toLevee. See Notes.Zone X Area with Flood Risk due to Levee Zone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood Hazard Zone D Channel, Culvert, or Storm SewerLevee, Dike, or Floodwall Cross Sections with 1% Annual Chance17.5 Water Surface ElevationCoastal Transect Coastal Transect BaselineProfile BaselineHydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of StudyJurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from theauthoritative NFHL web services provided by FEMA. This mapwas exported on 9/18/2019 at 12:24:12 PM and does notreflect changes or amendments subsequent to this date andtime. The NFHL and effective information may change orbecome superseded by new data over time. This map image is void if the one or more of the following mapelements do not appear: basemap imagery, flood zone labels,legend, scale bar, map creation date, community identifiers,FIRM panel number, and FIRM effective date. Map images forunmapped and unmodernized areas cannot be used forregulatory purposes. Legend OTHER AREAS OFFLOOD HAZARD OTHER AREAS GENERALSTRUCTURES OTHERFEATURES MAP PANELS 8 1:6,000 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. USGS The National Map: Orthoimagery. Data refreshed April, 2019. National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü116°15'17.07"W 33°37'35.63"N 116°14'39.62"W 33°37'5.67"N SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOODHAZARD AREAS Without Base Flood Elevation (BFE)Zone A, V, A99With BFE or Depth Zone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areasof 1% annual chance flood with averagedepth less than one foot or with drainageareas of less than one square mile Zone X Future Conditions 1% AnnualChance Flood Hazard Zone XArea with Reduced Flood Risk due toLevee. See Notes.Zone X Area with Flood Risk due to Levee Zone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood Hazard Zone D Channel, Culvert, or Storm SewerLevee, Dike, or Floodwall Cross Sections with 1% Annual Chance17.5 Water Surface ElevationCoastal Transect Coastal Transect BaselineProfile BaselineHydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of StudyJurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from theauthoritative NFHL web services provided by FEMA. This mapwas exported on 9/18/2019 at 12:29:49 PM and does notreflect changes or amendments subsequent to this date andtime. The NFHL and effective information may change orbecome superseded by new data over time. This map image is void if the one or more of the following mapelements do not appear: basemap imagery, flood zone labels,legend, scale bar, map creation date, community identifiers,FIRM panel number, and FIRM effective date. Map images forunmapped and unmodernized areas cannot be used forregulatory purposes. Legend OTHER AREAS OFFLOOD HAZARD OTHER AREAS GENERALSTRUCTURES OTHERFEATURES MAP PANELS 8 1:6,000 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. USGS The National Map: Orthoimagery. Data refreshed April, 2019. National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü116°15'17.67"W 33°37'53.05"N 116°14'40.22"W 33°37'23.10"N SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOODHAZARD AREAS Without Base Flood Elevation (BFE)Zone A, V, A99With BFE or Depth Zone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areasof 1% annual chance flood with averagedepth less than one foot or with drainageareas of less than one square mile Zone X Future Conditions 1% AnnualChance Flood Hazard Zone XArea with Reduced Flood Risk due toLevee. See Notes.Zone X Area with Flood Risk due to Levee Zone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood Hazard Zone D Channel, Culvert, or Storm SewerLevee, Dike, or Floodwall Cross Sections with 1% Annual Chance17.5 Water Surface ElevationCoastal Transect Coastal Transect BaselineProfile BaselineHydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of StudyJurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from theauthoritative NFHL web services provided by FEMA. This mapwas exported on 9/18/2019 at 12:32:40 PM and does notreflect changes or amendments subsequent to this date andtime. The NFHL and effective information may change orbecome superseded by new data over time. This map image is void if the one or more of the following mapelements do not appear: basemap imagery, flood zone labels,legend, scale bar, map creation date, community identifiers,FIRM panel number, and FIRM effective date. Map images forunmapped and unmodernized areas cannot be used forregulatory purposes. Legend OTHER AREAS OFFLOOD HAZARD OTHER AREAS GENERALSTRUCTURES OTHERFEATURES MAP PANELS 8 1:6,000 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. DEFINITIONS OF FEMA FLOOD ZONE DESIGNATIONS Moderate to Low Risk Areas In communities that participate in the NFIP, flood insurance is available to all property owners and renters in these zones: ZONE DESCRIPTION X (Shaded) Areas of 0.2% annual chance flood; areas of 1% annual chance flood with average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas protected by levees from 1% annual chance flood. Insurance purchase is not required in these zones. X Areas determined to be outside the 0.2% annual chance floodplain. High Risk Areas In communities that participate in the NFIP, mandatory flood insurance purchase requirements apply to all of these zones: ZONE DESCRIPTION A Areas with a 1% annual chance of flooding and a 26% chance of flooding over the life of a 30-year mortgage. Because detailed analyses are not performed for such areas; no depths or base flood elevations are shown within these zones. AE Areas with a 1% annual chance of flooding and a 26% chance of flooding over the life of a 30-year mortgage. In most instances, base flood elevations derived from detailed analyses are shown at selected intervals within these zones. AH Areas with a 1% annual chance of shallow flooding, usually in the form of a pond, with an average depth ranging from 1 to 3 feet. These areas have a 26% chance of flooding over the life of a 30-year mortgage. Base flood elevations derived from detailed analyses are shown at selected intervals within these zones. AO River or stream flood hazard areas, and areas with a 1% or greater chance of shallow flooding each year, usually in the form of sheet flow, with an average depth ranging from 1 to 3 feet. These areas have a 26% chance of flooding over the life of a 30-year mortgage. Average flood depths derived from detailed analyses are shown within these zones. For areas of alluvial fan flooding, velocities are also determined. AR Areas with a temporarily increased flood risk due to the building or restoration of a flood control system (such as a levee or a dam). Mandatory flood insurance purchase requirements will apply, but rates will not exceed the rates for unnumbered A zones if the structure is built or restored in compliance with Zone AR floodplain management regulations. A99 Areas with a 1% annual chance of flooding that will be protected by a Federal flood control system where construction has reached specified legal requirements. No depths or base flood elevations are shown within these zones. High Risk – Coastal Areas In communities that participate in the NFIP, mandatory flood insurance purchase requirements apply to all of these zones: ZONE DESCRIPTION V Coastal areas with a 1% or greater chance of flooding and an additional hazard associated with storm waves. These areas have a 26% chance of flooding over the life of a 30-year mortgage. No base flood elevations are shown within these zones. VE Coastal areas with a 1% or greater chance of flooding and an additional hazard associated with storm waves. These areas have a 26% chance of flooding over the life of a 30-year mortgage. Base flood elevations derived from detailed analyses are shown at selected intervals within these zones. Undetermined Risk Areas ZONE DESCRIPTION D Areas with possible but undetermined flood hazards. No flood hazard analysis has been conducted. Flood insurance rates are commensurate with the uncertainty of the flood risk. Coral Mountain Master Plan Hydrology Report Appendix C USDA NCSS Hydrologic Soils Map Hydrologic Soil Group—Riverside County, Coachella Valley Area, California (THE WAVE) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/18/2019 Page 1 of 4371910037194003719700372000037203003720600372090037212003721500371910037194003719700372000037203003720600372090037212003721500568100568400568700569000569300569600569900 568100 568400 568700 569000 569300 569600 569900 33° 37' 56'' N 116° 16' 1'' W33° 37' 56'' N116° 14' 42'' W33° 36' 28'' N 116° 16' 1'' W33° 36' 28'' N 116° 14' 42'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 500 1000 2000 3000Feet 0 150 300 600 900Meters Map Scale: 1:13,200 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Riverside County, Coachella Valley Area, California Survey Area Data: Version 10, Sep 13, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Dec 31, 2009—Oct 14, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Hydrologic Soil Group—Riverside County, Coachella Valley Area, California (THE WAVE) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/18/2019 Page 2 of 4 Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI CdC Carsitas gravelly sand, 0 to 9 percent slopes A 50.9 6.9% CpA Coachella fine sand, 0 to 2 percent slopes A 50.2 6.8% CsA Coachella fine sandy loam, 0 to 2 percent slopes A 46.2 6.3% GaB Gilman loamy fine sand, 0 to 5 percent slopes B 23.4 3.2% GbA Gilman fine sandy loam, 0 to 2 percent slopes B 78.0 10.6% GbB Gilman fine sandy loam, 2 to 5 percent slopes B 10.7 1.5% GcA Gilman fine sandy loam, wet, 0 to 2 percent slopes B 89.1 12.1% GfA Gilman silt loam, wet, 0 to 2 percent slopes B 0.0 0.0% Ip Indio fine sandy loam B 40.7 5.5% Ir Indio fine sandy loam, wet B 70.9 9.6% Is Indio very fine sandy loam B 46.3 6.3% It Indio very fine sandy loam, wet B 127.7 17.3% MaB Myoma fine sand, 0 to 5 percent slopes A 55.0 7.4% RO Rock outcrop 49.8 6.7% Totals for Area of Interest 739.0 100.0% Hydrologic Soil Group—Riverside County, Coachella Valley Area, California THE WAVE Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/18/2019 Page 3 of 4 Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Hydrologic Soil Group—Riverside County, Coachella Valley Area, California THE WAVE Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 9/18/2019 Page 4 of 4 Coral Mountain Master Plan Hydrology Report Appendix D NOAA Atlas 14 RCFCD Reference Plates 9/18/2019 Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=33.6202&lon=-116.2562&data=depth&units=english&series=pds NOAA Atlas 14, Volume 6, Version 2 Location name: La Quinta, California, USA* Latitude: 33.6202°, Longitude: -116.2562° Elevation: -31.22 ft** * source: ESRI Maps ** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES Sanja Perica, Sarah Dietz, Sarah Heim, Lillian Hiner, Kazungu Maitaria, Deborah Martin, Sandra Pavlovic, Ishani Roy, Carl Trypaluk, Dale Unruh, Fenglin Yan, Michael Yekta, Tan Zhao, Geoffrey Bonnin, Daniel Brewer, Li-Chuan Chen, Tye Parzybok, John Yarchoan NOAA, National Weather Service, Silver Spring, Maryland PF_tabular | PF_graphical | Maps_&_aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5-min 0.066 (0.056‑0.080) 0.103 (0.086‑0.124) 0.156 (0.130‑0.189) 0.203 (0.168‑0.249) 0.277 (0.221‑0.350) 0.340 (0.265‑0.440) 0.412 (0.313‑0.547) 0.494 (0.365‑0.675) 0.622 (0.440‑0.887) 0.737 (0.504‑1.09) 10-min 0.095 (0.080‑0.115) 0.147 (0.123‑0.178) 0.223 (0.186‑0.271) 0.292 (0.241‑0.357) 0.397 (0.316‑0.502) 0.488 (0.380‑0.631) 0.590 (0.449‑0.783) 0.708 (0.524‑0.967) 0.891 (0.631‑1.27) 1.06 (0.722‑1.56) 15-min 0.115 (0.096‑0.139) 0.178 (0.148‑0.215) 0.270 (0.225‑0.327) 0.353 (0.291‑0.432) 0.480 (0.382‑0.607) 0.590 (0.460‑0.763) 0.714 (0.543‑0.947) 0.856 (0.633‑1.17) 1.08 (0.763‑1.54) 1.28 (0.873‑1.89) 30-min 0.165 (0.138‑0.200) 0.255 (0.213‑0.309) 0.387 (0.322‑0.470) 0.506 (0.418‑0.619) 0.688 (0.549‑0.872) 0.846 (0.660‑1.10) 1.02 (0.780‑1.36) 1.23 (0.909‑1.68) 1.55 (1.10‑2.21) 1.83 (1.25‑2.71) 60-min 0.232 (0.194‑0.280) 0.358 (0.299‑0.433) 0.543 (0.452‑0.660) 0.711 (0.586‑0.870) 0.966 (0.771‑1.22) 1.19 (0.927‑1.54) 1.44 (1.10‑1.91) 1.73 (1.28‑2.36) 2.17 (1.54‑3.10) 2.57 (1.76‑3.80) 2-hr 0.322 (0.269‑0.389) 0.473 (0.395‑0.572) 0.698 (0.581‑0.848) 0.906 (0.747‑1.11) 1.23 (0.979‑1.56) 1.51 (1.18‑1.95) 1.83 (1.39‑2.43) 2.20 (1.63‑3.01) 2.77 (1.96‑3.95) 3.28 (2.24‑4.85) 3-hr 0.388 (0.324‑0.468) 0.559 (0.467‑0.676) 0.818 (0.681‑0.993) 1.06 (0.873‑1.30) 1.43 (1.14‑1.82) 1.76 (1.38‑2.28) 2.14 (1.63‑2.84) 2.58 (1.91‑3.53) 3.26 (2.31‑4.65) 3.87 (2.65‑5.72) 6-hr 0.508 (0.425‑0.614) 0.726 (0.606‑0.879) 1.06 (0.880‑1.28) 1.36 (1.13‑1.67) 1.84 (1.47‑2.34) 2.27 (1.77‑2.94) 2.76 (2.10‑3.66) 3.32 (2.46‑4.54) 4.21 (2.98‑6.00) 5.00 (3.42‑7.38) 12-hr 0.610 (0.509‑0.737) 0.893 (0.745‑1.08) 1.32 (1.10‑1.60) 1.70 (1.41‑2.08) 2.30 (1.83‑2.91) 2.82 (2.20‑3.65) 3.42 (2.60‑4.53) 4.10 (3.03‑5.60) 5.14 (3.64‑7.33) 6.07 (4.15‑8.96) 24-hr 0.759 (0.671‑0.875) 1.15 (1.01‑1.33) 1.72 (1.51‑1.99) 2.23 (1.95‑2.60) 3.00 (2.54‑3.62) 3.67 (3.05‑4.51) 4.41 (3.58‑5.55) 5.25 (4.15‑6.79) 6.53 (4.95‑8.77) 7.63 (5.60‑10.6) 2-day 0.871 (0.771‑1.00) 1.34 (1.18‑1.54) 2.01 (1.77‑2.33) 2.61 (2.28‑3.05) 3.51 (2.97‑4.22) 4.27 (3.54‑5.24) 5.11 (4.14‑6.42) 6.04 (4.77‑7.81) 7.44 (5.65‑10.0) 8.63 (6.34‑12.0) 3-day 0.936 (0.828‑1.08) 1.44 (1.28‑1.67) 2.18 (1.92‑2.52) 2.83 (2.47‑3.30) 3.79 (3.21‑4.57) 4.61 (3.83‑5.66) 5.50 (4.46‑6.92) 6.50 (5.13‑8.40) 7.98 (6.06‑10.7) 9.24 (6.79‑12.9) 4-day 0.994 (0.880‑1.15) 1.54 (1.36‑1.77) 2.31 (2.04‑2.68) 3.00 (2.63‑3.50) 4.02 (3.41‑4.85) 4.88 (4.06‑6.00) 5.83 (4.73‑7.33) 6.88 (5.43‑8.89) 8.43 (6.40‑11.3) 9.76 (7.16‑13.6) 7-day 1.06 (0.935‑1.22) 1.63 (1.44‑1.88) 2.45 (2.16‑2.83) 3.17 (2.77‑3.70) 4.24 (3.59‑5.11) 5.14 (4.26‑6.31) 6.12 (4.96‑7.69) 7.20 (5.69‑9.30) 8.81 (6.68‑11.8) 10.2 (7.46‑14.1) 10-day 1.09 (0.961‑1.25) 1.67 (1.48‑1.93) 2.52 (2.22‑2.91) 3.26 (2.85‑3.80) 4.36 (3.69‑5.25) 5.28 (4.38‑6.48) 6.28 (5.09‑7.90) 7.38 (5.83‑9.54) 9.01 (6.84‑12.1) 10.4 (7.62‑14.4) 20-day 1.17 (1.03‑1.35) 1.82 (1.61‑2.10) 2.75 (2.42‑3.18) 3.57 (3.12‑4.17) 4.78 (4.05‑5.76) 5.79 (4.81‑7.12) 6.89 (5.59‑8.66) 8.09 (6.39‑10.4) 9.83 (7.46‑13.2) 11.3 (8.29‑15.7) 30-day 1.24 (1.10‑1.43) 1.96 (1.73‑2.26) 2.99 (2.63‑3.46) 3.90 (3.41‑4.55) 5.24 (4.44‑6.31) 6.35 (5.27‑7.81) 7.55 (6.12‑9.50) 8.86 (6.99‑11.4) 10.7 (8.16‑14.5) 12.3 (9.04‑17.1) 45-day 1.34 (1.19‑1.55) 2.15 (1.90‑2.49) 3.32 (2.93‑3.85) 4.35 (3.81‑5.08) 5.88 (4.98‑7.08) 7.14 (5.93‑8.77) 8.49 (6.89‑10.7) 9.96 (7.87‑12.9) 12.1 (9.16‑16.2) 13.8 (10.1‑19.2) 60-day 1.42 (1.26‑1.64) 2.31 (2.04‑2.67) 3.60 (3.17‑4.17) 4.73 (4.14‑5.52) 6.40 (5.42‑7.71) 7.78 (6.46‑9.56) 9.27 (7.52‑11.7) 10.9 (8.58‑14.0) 13.2 (9.98‑17.7) 15.0 (11.0‑20.9) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are notchecked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. PF graphical PROJECT NAME PROJECT NUMBER 2553 STORM EVENT 100 yr DATE: MINUTES RAINFALL RAINFALL INTENSITY DEPTH (in/hr)(in) 5 4.94 0.41 10 3.54 0.59 15 2.86 0.71 30 2.04 1.02 60 1.44 1.44 120 0.92 1.83 CONSTANT FROM GRAPH 11.76 EXPONENT FROM GRAPH -0.52 MINUTES RAINFALL RAINFALL INTENSITY DEPTH (in/hr)(in) 5 5.09 0.42 10 3.55 0.59 15 2.88 0.72 20 2.48 0.83 25 2.21 0.92 30 2.01 1.00 35 1.85 1.08 40 1.73 1.15 45 1.62 1.22 50 1.54 1.28 55 1.46 1.34 60 1.40 1.40 65 1.34 1.45 70 1.29 1.51 75 1.25 1.56 80 1.20 1.61 85 1.17 1.65 90 1.13 1.70 95 1.10 1.74 100 1.07 1.79 105 1.05 1.83 110 1.02 1.87 115 1.00 1.91 120 0.98 1.95 INTENSITY VALUES FROM GRAPH NOAA ATLAS 14 INTENSITY - DURATION WORKSHEET THE WAVE DATA FROM NOAA ATLAS 14 September 18, 2019 y = 11.76x-0.52 0.10 1.00 10.00 1 10 100 1000 Coral Mountain Master Plan Hydrology Report Appendix E Preliminary Land Use Worksheets MSA JOB #2553 HYDROLOGIC SOIL GROUP B DRAINAGE AREA ROCK EXIST STREETS WATER COMMERCIAL PROPOSED PROPOSED PROPOSED PROPOSED TOTAL OUTCROPPING OPEN BRUSH WALKS FEATURE AREA RESIDENTIAL - LD RESIDENTIAL - MD RESIDENTIAL - HD OPEN SPACE RI=93 RI=76 RI=56 RI=56 RI=56 RI=56 RI=56 RI=56 RI=56 (acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres) DA-A 35.652 35.233 2.082 18.699 5.752 0.000 0.000 8.141 57.186 162.745 DA-B 0.000 0.000 2.581 6.423 1.483 20.347 0.000 0.000 10.752 41.586 DA-C 0.000 0.000 1.455 0.000 0.000 0.000 4.092 2.159 2.485 10.191 DA-D 0.000 0.000 2.588 2.323 4.803 0.000 0.000 7.637 11.052 28.403 DA-E 0.000 0.000 1.707 0.000 0.000 48.170 0.000 4.271 7.654 61.802 SUBTOTAL 35.652 35.233 10.413 27.445 12.038 68.517 4.092 22.208 89.129 304.727 FUTURE BNDY - F 0.000 0.000 0.353 0.000 0.000 42.760 0.000 0.000 1.698 44.811 FUTURE BNDY - G 0.000 0.000 0.316 0.000 0.000 33.880 0.000 0.000 1.546 35.742 FUTURE BNDY - H 0.000 0.000 0.000 0.000 7.118 0.000 0.000 0.000 0.000 7.118 FUTURE BNDY - I 0.000 0.000 0.470 0.000 0.000 47.890 0.000 0.000 3.269 51.629 TOTAL ON-SITE 35.652 35.233 11.552 27.445 19.156 193.047 4.092 22.208 95.642 444.027 OFF-SITE NORTH 0.000 0.000 5.754 0.000 0.000 0.000 0.000 0.000 5.950 11.704 OFF-SITE SOUTH 0.000 0.000 4.014 0.000 0.000 0.000 0.000 0.000 1.687 5.701 TOTAL OFF-SITE 0.000 0.000 9.768 0.000 0.000 0.000 0.000 0.000 7.637 17.405 TOTAL HYDROLOGIC AREA 35.652 35.233 21.320 27.445 19.156 193.047 4.092 22.208 103.279 461.432 AREA RECONCILIATION MEASURED AREAS: ROCK OUTCROPPING 35.652 EXIST OPEN BRUSH 35.233 STREETS/WALKS 21.320 WATER FEATURE 27.445 COMMERCIAL 19.156 LOTS - LOW DENSITY 193.047 LOTS - MED DENSITY 4.092 LOTS - HIGH DENSITY 22.208 OPEN SPACE 103.279 TOTAL HYDROLOGIC AREA 461.432 SURVEY BOUNDARY 384.389 ADD:77.080 SUBTRACT:0.037 TOTAL AREA:461.432 TTM 37815 - CORAL MOUNTAIN January 27, 2021 PROPOSED LAND USE PROPOSED LAND USE AREAS - SYNTHETIC UNIT MSA JOB #2553 HYDROLOGIC SOIL GROUP B DRAINAGE AREA ROCK EXIST STREETS WATER COMMERCIAL PROPOSED PROPOSED PROPOSED PROPOSED TOTAL OUTCROPPING OPEN BRUSH WALKS FEATURE AREA RESIDENTIAL - LD RESIDENTIAL - MD RESIDENTIAL - HD OPEN SPACE RI=93 RI=76 RI=56 RI=56 RI=56 RI=56 RI=56 RI=56 RI=56 (acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres) DA-A1 34.384 30.363 0.000 0.000 0.000 0.000 0.000 0.000 23.665 88.412 DA-A2 0.000 0.000 2.071 0.000 5.752 0.000 0.000 8.141 1.350 17.314 DA-A3 1.268 4.870 0.011 0.000 0.000 0.000 0.000 0.000 18.819 24.968 DA-A4 0.000 0.000 0.000 18.699 0.000 0.000 0.000 0.000 13.352 32.051 TOTAL - DA-A 35.652 35.233 2.082 18.699 5.752 0.000 0.000 8.141 57.186 162.745 TTM 37815 - CORAL MOUNTAIN PROPOSED LAND USE AREAS - SYNTHETIC UNIT January 27, 2021 PROPOSED LAND USE MSA JOB #2553 HYDROLOGIC SOIL GROUP A DRAINAGE AREA ROCK EXISTING STREETS WATER COMMERCIAL RESIDENTIAL RESIDENTIAL RESIDENTIAL OPEN TOTAL IMPERVIOUS OUT-CROPPING OPEN BRUCH WALKS FEATURES LOW DENSITY MEDIUM DENSITY HIGH DENSITY SPACE AREA Ai=5%Ai=5%Ai=100%Ai=100%Ai=90%Ai=30%Ai=40%Ai=50%Ai=10% (acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres)(acres) DA-A 35.652 35.233 2.082 18.699 5.752 0.000 0.000 8.141 57.186 162.745 39.291 DA-B 0.000 0.000 2.581 6.423 1.483 20.347 0.000 0.000 10.752 41.586 17.518 DA-C 0.000 0.000 1.455 0.000 0.000 0.000 4.092 2.159 2.485 10.191 4.420 DA-D 0.000 0.000 2.588 2.323 4.803 0.000 0.000 7.637 11.052 28.403 14.157 DA-E 0.000 0.000 1.707 0.000 0.000 48.170 0.000 4.271 7.654 61.802 19.059 SUBTOTAL 35.652 35.233 10.413 27.445 12.038 68.517 4.092 22.208 89.129 304.727 94.445 DA-F 0.000 0.000 0.353 0.000 0.000 42.760 0.000 0.000 1.698 44.811 13.351 DA-G 0.000 0.000 0.316 0.000 0.000 33.880 0.000 0.000 1.546 35.742 10.635 DA-H 0.000 0.000 0.000 0.000 7.118 0.000 0.000 0.000 0.000 7.118 6.406 DA-I 0.000 0.000 0.470 0.000 0.000 47.890 0.000 0.000 3.269 51.629 15.164 TOTAL ON-SITE 35.652 35.233 11.552 27.445 19.156 193.047 4.092 22.208 95.642 444.027 140.001 OFF-SITE NORTH 0.000 0.000 5.754 0.000 0.000 0.000 0.000 0.000 5.950 11.704 6.349 OFFSITE - SOUTH 0.000 0.000 4.014 0.000 0.000 0.000 0.000 0.000 1.687 5.701 4.183 TOTAL OFF-SITE 0.000 0.000 9.768 0.000 0.000 0.000 0.000 0.000 7.637 17.405 10.532 TOTAL HYDROLOGIC AREA 35.652 35.233 21.320 27.445 19.156 193.047 4.092 22.208 103.279 461.432 150.532 TTM 37815 - CORAL MOUNTAIN WQMP LAND USE - IMPERVIOUS AREAS January 27, 2021 LAND USE Coral Mountain Master Plan Hydrology Report Appendix F RCFCD Synthetic Unit Hydrograph Worksheets DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 11 D EXISTING BARREN 34.384 X 93 0.09 0.05 12 B EXISTING OPEN BRUSH - POOR 30.363 X 76 0.29 0.05 2 B PAVING/HARDSCAPE 0.000 D 56 0.51 1.00 3 B WATER FEATURE 0.000 D 56 0.51 1.00 1 B COMMERCIAL 0.000 D 56 0.51 0.90 6 B SF - HIGH DENSITY 0.000 D 56 0.51 0.50 9 B LANDSCAPING 23.665 D 56 0.51 0.10 1,180 ft 590 ft 960.0 ft ELEVATION OF CONCENTRATION POINT 461.0 ft 0.03 10 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 0.71 in 3-HOUR 1.06 in 6-HOUR 1.36 in 24-HOUR 2.23 in BASIN CHARACTERISTICS:ELEVATION AREA 459.0 ft 65,765 sf 460.0 ft 77,310 sf 461.0 ft 89,480 sf PERCOLATION RATE (in/hr)1.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 10 YEAR BASIN AMC NUMBER RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE March 30, 2020 CORAL MOUNTAIN LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-A1 Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:3/30/20 [1] AMC II [2] FREQUENCY-YEARS 10 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 0.71 in 3-HOUR 1.06 in 6-HOUR 1.36 in 24-HOUR 2.23 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)228,186 340,193 436,474 715,689 SOIL LOSSES (cu-ft)81,121 209,809 309,926 625,214 EFFECTIVE RAIN (in)0.46 0.41 0.39 0.28 FLOOD VOLUME (cu-ft)147,065 130,384 126,548 90,475 (acre-ft)3.38 2.99 2.91 2.08 REQUIRED STORAGE (cu-ft)140,938 113,286 95,565 19,645 (acre-ft)3.24 2.60 2.19 0.45 FACTOR OF SAFETY 1.10 1.37 1.62 7.88 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 70.45 58.94 7.64 MAXIMUM WSEL (ft)460.83 460.50 460.29 459.27 DEPTH (ft)1.83 1.50 1.29 0.27 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days)1.0 0.9 1.0 1.0 10 YEAR BASIN DA-A1 CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 88.412 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION [3] AREA - ACRES [4] L-FEET [5] L-MILES 1180 0.223 [13] L*LCA/S^0.5 47.25 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.001 590.00 [12] S^0.5 0.112 2232.8 960 461 499 0.03 [17] 100% OF LAG-MINUTES 2.5 2.5 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.04 [16] LAG TIME-MINUTES [18] 200% OF LAG-MINUTES RAINFALL DATA 4.9 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 154,781 3.55 Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:3/30/20 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] D 93 0.09 5%0.09 34.384 0.389 0.0334 UNDEVELOPED 0.9000 0.3500 B 76 0.29 5%0.28 30.363 0.343 0.0951 UNDEVELOPED 0.9000 0.3091 B 56 0.51 100%0.05 0.000 0.000 0.0000 DEVELOPED 0.1000 0.0000 B 56 0.51 100%0.05 0.000 0.000 0.0000 DEVELOPED 0.1000 0.0000 B 56 0.51 90%0.10 0.000 0.000 0.0000 DEVELOPED 0.1800 0.0000 B 56 0.51 50%0.28 0.000 0.000 0.0000 DEVELOPED 0.5000 0.0000 B 56 0.51 10%0.46 23.665 0.268 0.1242 DEVELOPED 0.8200 0.2195 SUM 88.412 SUM 0.2528 0.8786 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.126381397 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00234 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00234 0.13 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.2528 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8786 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II (24-(T/60))^1.55 + LAND USE EXISTING BARREN EXISTING OPEN BRUSH - POOR PAVING/HARDSCAPE WATER FEATURE COMMERCIAL SF - HIGH DENSITY LANDSCAPING Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 88.41 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.46 Maxwell Drywells UNIT TIME-PERCENT OF LAG 203.6 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 0.71 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.25 LOW LOSS RATE - PERCENT 87.86% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.31 0.25 0.27 0.05 4.85 1,455 1,455 66,000 458 458 996 0.02 459.01 2 10 0.17 4.2 0.36 0.25 0.31 0.11 9.41 2,824 3,820 66,382 461 461 3,359 0.08 459.05 3 15 0.25 4.4 0.38 0.25 0.33 0.12 10.93 3,280 6,639 66,838 464 464 6,175 0.14 459.09 4 20 0.33 4.6 0.39 0.25 0.34 0.14 12.45 3,736 9,911 67,366 468 468 9,444 0.22 459.13 5 25 0.42 5.0 0.43 0.25 0.37 0.17 15.50 4,649 14,093 68,042 473 473 13,620 0.31 459.19 6 30 0.50 5.6 0.48 0.25 0.42 0.23 20.06 6,018 19,639 68,938 479 479 19,160 0.44 459.27 7 35 0.58 6.4 0.55 0.25 0.48 0.29 26.15 7,844 27,004 70,128 487 487 26,517 0.61 459.37 8 40 0.67 8.1 0.69 0.25 0.61 0.44 39.08 11,723 38,240 71,943 500 500 37,740 0.87 459.53 9 45 0.75 13.1 1.12 0.25 0.98 0.86 77.11 23,132 60,873 75,600 525 525 60,348 1.39 459.84 10 50 0.83 34.5 2.94 0.25 2.59 2.69 239.88 71,964 132,312 86,198 599 599 131,713 3.02 460.72 11 55 0.92 6.7 0.57 0.25 0.50 0.32 28.43 8,528 140,241 87,356 607 607 139,635 3.21 460.82 12 60 1.00 3.8 0.32 0.25 0.28 0.07 6.37 1,911 141,546 87,547 608 608 140,938 3.24 460.83 TOTAL RAINFALL 0.71 in RAINFALL VOLUME 228,186 cu-ft SOIL LOSSES 81,121 cu-ft EFFECTIVE RAIN 0.46 in FLOOD VOLUME 3.38 acft FLOOD VOLUME 147,065 cu-ft REQUIRED STORAGE 3.24 REQUIRED STORAGE 140,938 cu-ft MAX WSEL 460.83 ft PEAK FLOW RATE 239.88 cfs TOTAL BASIN LOSSES 6,127 cu-ft AVERAGE PERCOLATION RATE 102.12 cf/min CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 88.41 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.46 Maxwell Drywells UNIT TIME-PERCENT OF LAG 203.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.06 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.25 LOW LOSS RATE - PERCENT 87.86% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.17 0.25 0.15 0.02 1.79 537 537 65,852 457 457 80 0.00 459.00 2 10 0.17 1.3 0.17 0.25 0.15 0.02 1.79 537 617 65,865 457 457 159 0.00 459.00 3 15 0.25 1.1 0.14 0.25 0.12 0.02 1.51 454 614 65,864 457 457 156 0.00 459.00 4 20 0.33 1.5 0.19 0.25 0.17 0.02 2.07 620 776 65,890 458 458 318 0.01 459.00 5 25 0.42 1.5 0.19 0.25 0.17 0.02 2.07 620 938 65,916 458 458 480 0.01 459.01 6 30 0.50 1.8 0.23 0.25 0.20 0.03 2.48 743 1,223 65,963 458 458 765 0.02 459.01 7 35 0.58 1.5 0.19 0.25 0.17 0.02 2.07 620 1,385 65,989 458 458 927 0.02 459.01 8 40 0.67 1.8 0.23 0.25 0.20 0.03 2.48 743 1,670 66,035 459 459 1,212 0.03 459.02 9 45 0.75 1.8 0.23 0.25 0.20 0.03 2.48 743 1,955 66,081 459 459 1,496 0.03 459.02 10 50 0.83 1.5 0.19 0.25 0.17 0.02 2.07 620 2,116 66,107 459 459 1,657 0.04 459.02 11 55 0.92 1.6 0.20 0.25 0.18 0.02 2.20 661 2,317 66,139 459 459 1,858 0.04 459.03 12 60 1.00 1.8 0.23 0.25 0.20 0.03 2.48 743 2,602 66,185 460 460 2,142 0.05 459.03 13 65 1.08 2.2 0.28 0.25 0.25 0.03 2.41 724 2,866 66,228 460 460 2,406 0.06 459.03 14 70 1.17 2.2 0.28 0.25 0.25 0.03 2.41 724 3,130 66,271 460 460 2,670 0.06 459.04 15 75 1.25 2.2 0.28 0.25 0.25 0.03 2.41 724 3,394 66,313 461 461 2,934 0.07 459.04 16 80 1.33 2.0 0.25 0.25 0.22 0.00 0.15 44 2,978 66,246 460 460 2,518 0.06 459.04 17 85 1.42 2.6 0.33 0.25 0.29 0.08 6.95 2,085 4,603 66,509 462 462 4,141 0.10 459.06 18 90 1.50 2.7 0.34 0.25 0.30 0.09 8.08 2,425 6,566 66,826 464 464 6,102 0.14 459.09 19 95 1.58 2.4 0.31 0.25 0.27 0.05 4.68 1,405 7,506 66,978 465 465 7,041 0.16 459.10 20 100 1.67 2.7 0.34 0.25 0.30 0.09 8.08 2,425 9,466 67,294 467 467 8,999 0.21 459.13 21 105 1.75 3.3 0.42 0.25 0.37 0.17 14.89 4,466 13,465 67,940 472 472 12,994 0.30 459.18 22 110 1.83 3.1 0.39 0.25 0.35 0.14 12.62 3,786 16,779 68,476 476 476 16,304 0.37 459.23 23 115 1.92 2.9 0.37 0.25 0.32 0.12 10.35 3,106 19,409 68,901 478 478 18,931 0.43 459.26 24 120 2.00 3.0 0.38 0.25 0.34 0.13 11.49 3,446 22,377 69,380 482 482 21,895 0.50 459.31 25 125 2.08 3.1 0.39 0.25 0.35 0.14 12.62 3,786 25,681 69,914 486 486 25,195 0.58 459.35 Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 88.41 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.46 Maxwell Drywells UNIT TIME-PERCENT OF LAG 203.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.06 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.25 LOW LOSS RATE - PERCENT 87.86% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD 26 130 2.17 4.2 0.53 0.25 0.47 0.28 25.09 7,528 32,723 71,052 493 493 32,230 0.74 459.45 27 135 2.25 5.0 0.64 0.25 0.56 0.38 34.17 10,250 42,479 72,628 504 504 41,975 0.96 459.59 28 140 2.33 3.5 0.45 0.25 0.39 0.19 17.16 5,147 47,122 73,378 510 510 46,612 1.07 459.65 29 145 2.42 6.8 0.86 0.25 0.76 0.61 54.58 16,373 62,985 75,941 527 527 62,458 1.43 459.87 30 150 2.50 7.3 0.93 0.25 0.82 0.68 60.25 18,074 80,532 78,635 546 546 79,986 1.84 460.10 31 155 2.58 8.2 1.04 0.25 0.92 0.79 70.45 21,136 101,122 81,642 567 567 100,555 2.31 460.35 32 160 2.67 5.9 0.75 0.25 0.66 0.50 44.37 13,311 113,866 83,504 580 580 113,286 2.60 460.50 33 165 2.75 2.0 0.25 0.25 0.22 0.00 0.15 44 113,330 83,426 579 579 112,751 2.59 460.50 34 170 2.83 1.8 0.23 0.25 0.20 0.03 2.48 743 113,494 83,450 580 580 112,914 2.59 460.50 35 175 2.92 1.8 0.23 0.25 0.20 0.03 2.48 743 113,658 83,474 580 580 113,078 2.60 460.50 36 180 3.00 0.6 0.08 0.25 0.07 0.01 0.83 248 113,326 83,425 579 579 112,747 2.59 460.50 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 209,809 cu-ft 1.06 in 340,193 cu-ft 460.50 ft 70.45 cfs 17,637 cu-ft 97.98 cf/min 0.41 in 2.99 acft 130,384 cu-ft 2.60 acft 113,286 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 88.41 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.46 Maxwell Drywells UNIT TIME-PERCENT OF LAG 203.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.36 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.25 LOW LOSS RATE - PERCENT 87.86% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.08 0.25 0.07 0.01 0.88 265 265 65,808 457 265 0 0.00 459.00 2 10 0.17 0.6 0.10 0.25 0.09 0.01 1.06 318 318 65,816 457 318 0 0.00 459.00 3 15 0.25 0.6 0.10 0.25 0.09 0.01 1.06 318 318 65,816 457 318 0 0.00 459.00 4 20 0.33 0.6 0.10 0.25 0.09 0.01 1.06 318 318 65,816 457 318 0 0.00 459.00 5 25 0.42 0.6 0.10 0.25 0.09 0.01 1.06 318 318 65,816 457 318 0 0.00 459.00 6 30 0.50 0.7 0.11 0.25 0.10 0.01 1.24 371 371 65,825 457 371 0 0.00 459.00 7 35 0.58 0.7 0.11 0.25 0.10 0.01 1.24 371 371 65,825 457 371 0 0.00 459.00 8 40 0.67 0.7 0.11 0.25 0.10 0.01 1.24 371 371 65,825 457 371 0 0.00 459.00 9 45 0.75 0.7 0.11 0.25 0.10 0.01 1.24 371 371 65,825 457 371 0 0.00 459.00 10 50 0.83 0.7 0.11 0.25 0.10 0.01 1.24 371 371 65,825 457 371 0 0.00 459.00 11 55 0.92 0.7 0.11 0.25 0.10 0.01 1.24 371 371 65,825 457 371 0 0.00 459.00 12 60 1.00 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 13 65 1.08 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 14 70 1.17 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 15 75 1.25 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 16 80 1.33 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 17 85 1.42 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 18 90 1.50 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 19 95 1.58 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 20 100 1.67 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 21 105 1.75 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 22 110 1.83 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 23 115 1.92 0.8 0.13 0.25 0.11 0.02 1.41 424 424 65,833 457 424 0 0.00 459.00 24 120 2.00 0.9 0.15 0.25 0.13 0.02 1.59 477 477 65,842 457 457 20 0.00 459.00 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 88.41 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.46 Maxwell Drywells UNIT TIME-PERCENT OF LAG 203.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.36 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.25 LOW LOSS RATE - PERCENT 87.86% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.13 0.25 0.11 0.02 1.41 424 444 65,837 457 444 0 0.00 459.00 26 130 2.17 0.9 0.15 0.25 0.13 0.02 1.59 477 477 65,842 457 457 20 0.00 459.00 27 135 2.25 0.9 0.15 0.25 0.13 0.02 1.59 477 497 65,845 457 457 39 0.00 459.00 28 140 2.33 0.9 0.15 0.25 0.13 0.02 1.59 477 516 65,848 457 457 59 0.00 459.00 29 145 2.42 0.9 0.15 0.25 0.13 0.02 1.59 477 536 65,852 457 457 79 0.00 459.00 30 150 2.50 0.9 0.15 0.25 0.13 0.02 1.59 477 556 65,855 457 457 98 0.00 459.00 31 155 2.58 0.9 0.15 0.25 0.13 0.02 1.59 477 575 65,858 457 457 118 0.00 459.00 32 160 2.67 0.9 0.15 0.25 0.13 0.02 1.59 477 595 65,861 457 457 137 0.00 459.00 33 165 2.75 1.0 0.16 0.25 0.14 0.02 1.77 530 667 65,873 457 457 210 0.00 459.00 34 170 2.83 1.0 0.16 0.25 0.14 0.02 1.77 530 740 65,885 458 458 282 0.01 459.00 35 175 2.92 1.0 0.16 0.25 0.14 0.02 1.77 530 812 65,896 458 458 355 0.01 459.00 36 180 3.00 1.0 0.16 0.25 0.14 0.02 1.77 530 885 65,908 458 458 427 0.01 459.01 37 185 3.08 1.0 0.16 0.25 0.14 0.02 1.77 530 957 65,920 458 458 499 0.01 459.01 38 190 3.17 1.1 0.18 0.25 0.16 0.02 1.94 583 1,082 65,940 458 458 624 0.01 459.01 39 195 3.25 1.1 0.18 0.25 0.16 0.02 1.94 583 1,207 65,960 458 458 749 0.02 459.01 40 200 3.33 1.1 0.18 0.25 0.16 0.02 1.94 583 1,332 65,980 458 458 874 0.02 459.01 41 205 3.42 1.2 0.20 0.25 0.17 0.02 2.12 636 1,510 66,009 458 458 1,051 0.02 459.01 42 210 3.50 1.3 0.21 0.25 0.19 0.03 2.30 689 1,740 66,046 459 459 1,282 0.03 459.02 43 215 3.58 1.4 0.23 0.25 0.20 0.03 2.47 742 2,023 66,092 459 459 1,564 0.04 459.02 44 220 3.67 1.4 0.23 0.25 0.20 0.03 2.47 742 2,306 66,138 459 459 1,847 0.04 459.03 45 225 3.75 1.5 0.24 0.25 0.22 0.03 2.65 795 2,642 66,192 460 460 2,182 0.05 459.03 46 230 3.83 1.5 0.24 0.25 0.22 0.03 2.65 795 2,977 66,246 460 460 2,517 0.06 459.04 47 235 3.92 1.6 0.26 0.25 0.23 0.01 0.75 224 2,741 66,208 460 460 2,281 0.05 459.03 48 240 4.00 1.6 0.26 0.25 0.23 0.01 0.75 224 2,504 66,170 460 460 2,045 0.05 459.03 49 245 4.08 1.7 0.28 0.25 0.24 0.02 2.20 660 2,705 66,202 460 460 2,245 0.05 459.03 50 250 4.17 1.8 0.29 0.25 0.26 0.04 3.65 1,096 3,342 66,305 460 460 2,881 0.07 459.04 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 88.41 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.46 Maxwell Drywells UNIT TIME-PERCENT OF LAG 203.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.36 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.25 LOW LOSS RATE - PERCENT 87.86% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.31 0.25 0.27 0.06 5.11 1,533 4,414 66,478 462 462 3,952 0.09 459.06 52 260 4.33 2.0 0.33 0.25 0.29 0.07 6.56 1,969 5,922 66,722 463 463 5,459 0.13 459.08 53 265 4.42 2.1 0.34 0.25 0.30 0.09 8.02 2,406 7,864 67,036 466 466 7,399 0.17 459.10 54 270 4.50 2.1 0.34 0.25 0.30 0.09 8.02 2,406 9,805 67,349 468 468 9,337 0.21 459.13 55 275 4.58 2.2 0.36 0.25 0.32 0.11 9.47 2,842 12,179 67,733 470 470 11,709 0.27 459.16 56 280 4.67 2.3 0.38 0.25 0.33 0.12 10.93 3,279 14,988 68,186 474 474 14,514 0.33 459.20 57 285 4.75 2.4 0.39 0.25 0.34 0.14 12.38 3,715 18,230 68,710 477 477 17,753 0.41 459.25 58 290 4.83 2.4 0.39 0.25 0.34 0.14 12.38 3,715 21,468 69,233 481 481 20,987 0.48 459.29 59 295 4.92 2.5 0.41 0.25 0.36 0.16 13.84 4,152 25,139 69,826 485 485 24,654 0.57 459.35 60 300 5.00 2.6 0.42 0.25 0.37 0.17 15.29 4,588 29,242 70,489 490 490 28,753 0.66 459.40 61 305 5.08 3.1 0.51 0.25 0.44 0.25 22.57 6,771 35,523 71,504 497 497 35,027 0.80 459.49 62 310 5.17 3.6 0.59 0.25 0.52 0.33 29.84 8,953 43,980 72,870 506 506 43,474 1.00 459.61 63 315 5.25 3.9 0.64 0.25 0.56 0.38 34.21 10,262 53,736 74,447 517 517 53,219 1.22 459.74 64 320 5.33 4.2 0.69 0.25 0.60 0.43 38.57 11,572 64,791 76,233 529 529 64,262 1.48 459.90 65 325 5.42 4.7 0.77 0.25 0.67 0.51 45.85 13,754 78,016 78,268 544 544 77,472 1.78 460.07 66 330 5.50 5.6 0.91 0.25 0.80 0.66 58.94 17,682 95,155 80,771 561 561 94,594 2.17 460.28 67 335 5.58 1.9 0.31 0.25 0.27 0.06 5.11 1,533 96,127 80,913 562 562 95,565 2.19 460.29 68 340 5.67 0.9 0.15 0.25 0.13 0.02 1.59 477 96,042 80,900 562 562 95,480 2.19 460.29 69 345 5.75 0.6 0.10 0.25 0.09 0.01 1.06 318 95,798 80,865 562 562 95,236 2.19 460.29 70 350 5.83 0.5 0.08 0.25 0.07 0.01 0.88 265 95,501 80,822 561 561 94,940 2.18 460.28 71 355 5.92 0.3 0.05 0.25 0.04 0.01 0.53 159 95,099 80,763 561 561 94,538 2.17 460.28 72 360 6.00 0.2 0.03 0.25 0.03 0.00 0.35 106 94,644 80,696 560 560 94,084 2.16 460.27 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 436,474 cu-ft 1.36 in 309,926 cu-ft 460.29 ft 58.94 cfs 90.18 cf/min 32,464 cu-ft 0.39 in 2.91 acft 126,548 cu-ft 2.19 acft 95,565 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 88.41 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.13 LAG TIME - MINUTES 2.46 C 0.00234 Maxwell Drywells UNIT TIME-PERCENT OF LAG 611%Low Loss Rate (percent)87.86%Number 0 TOTAL ADJUSTED STORM RAIN (in)2.23 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.018 0.446 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 2 30 0.50 0.3 0.027 0.441 0.024 0.00 0.29 261 261 65,807 1,371 261 0 0.00 459.00 3 45 0.75 0.3 0.027 0.436 0.024 0.00 0.29 261 261 65,807 1,371 261 0 0.00 459.00 4 60 1.00 0.4 0.036 0.431 0.031 0.00 0.39 348 348 65,821 1,371 348 0 0.00 459.00 5 75 1.25 0.3 0.027 0.426 0.024 0.00 0.29 261 261 65,807 1,371 261 0 0.00 459.00 6 90 1.50 0.3 0.027 0.421 0.024 0.00 0.29 261 261 65,807 1,371 261 0 0.00 459.00 7 105 1.75 0.3 0.027 0.416 0.024 0.00 0.29 261 261 65,807 1,371 261 0 0.00 459.00 8 120 2.00 0.4 0.036 0.411 0.031 0.00 0.39 348 348 65,821 1,371 348 0 0.00 459.00 9 135 2.25 0.4 0.036 0.406 0.031 0.00 0.39 348 348 65,821 1,371 348 0 0.00 459.00 10 150 2.50 0.4 0.036 0.401 0.031 0.00 0.39 348 348 65,821 1,371 348 0 0.00 459.00 11 165 2.75 0.5 0.045 0.396 0.039 0.01 0.48 434 434 65,835 1,372 434 0 0.00 459.00 12 180 3.00 0.5 0.045 0.391 0.039 0.01 0.48 434 434 65,835 1,372 434 0 0.00 459.00 13 195 3.25 0.5 0.045 0.386 0.039 0.01 0.48 434 434 65,835 1,372 434 0 0.00 459.00 14 210 3.50 0.5 0.045 0.381 0.039 0.01 0.48 434 434 65,835 1,372 434 0 0.00 459.00 15 225 3.75 0.5 0.045 0.377 0.039 0.01 0.48 434 434 65,835 1,372 434 0 0.00 459.00 16 240 4.00 0.6 0.054 0.372 0.047 0.01 0.58 521 521 65,849 1,372 521 0 0.00 459.00 17 255 4.25 0.6 0.054 0.367 0.047 0.01 0.58 521 521 65,849 1,372 521 0 0.00 459.00 18 270 4.50 0.7 0.062 0.363 0.055 0.01 0.68 608 608 65,863 1,372 608 0 0.00 459.00 19 285 4.75 0.7 0.062 0.358 0.055 0.01 0.68 608 608 65,863 1,372 608 0 0.00 459.00 20 300 5.00 0.8 0.071 0.353 0.063 0.01 0.77 695 695 65,877 1,372 695 0 0.00 459.00 21 315 5.25 0.6 0.054 0.349 0.047 0.01 0.58 521 521 65,849 1,372 521 0 0.00 459.00 22 330 5.50 0.7 0.062 0.344 0.055 0.01 0.68 608 608 65,863 1,372 608 0 0.00 459.00 23 345 5.75 0.8 0.071 0.340 0.063 0.01 0.77 695 695 65,877 1,372 695 0 0.00 459.00 24 360 6.00 0.8 0.071 0.335 0.063 0.01 0.77 695 695 65,877 1,372 695 0 0.00 459.00 25 375 6.25 0.9 0.080 0.331 0.071 0.01 0.87 782 782 65,891 1,373 782 0 0.00 459.00 26 390 6.50 0.9 0.080 0.326 0.071 0.01 0.87 782 782 65,891 1,373 782 0 0.00 459.00 27 405 6.75 1.0 0.089 0.322 0.078 0.01 0.97 869 869 65,905 1,373 869 0 0.00 459.00 28 420 7.00 1.0 0.089 0.318 0.078 0.01 0.97 869 869 65,905 1,373 869 0 0.00 459.00 29 435 7.25 1.0 0.089 0.313 0.078 0.01 0.97 869 869 65,905 1,373 869 0 0.00 459.00 30 450 7.50 1.1 0.098 0.309 0.086 0.01 1.06 956 956 65,919 1,373 956 0 0.00 459.00 31 465 7.75 1.2 0.107 0.305 0.094 0.01 1.16 1,043 1,043 65,933 1,374 1,043 0 0.00 459.00 32 480 8.00 1.3 0.116 0.301 0.102 0.01 1.26 1,130 1,130 65,948 1,374 1,130 0 0.00 459.00 33 495 8.25 1.5 0.134 0.296 0.118 0.02 1.45 1,303 1,303 65,976 1,374 1,303 0 0.00 459.00 34 510 8.50 1.5 0.134 0.292 0.118 0.02 1.45 1,303 1,303 65,976 1,374 1,303 0 0.00 459.00 35 525 8.75 1.6 0.143 0.288 0.125 0.02 1.54 1,390 1,390 65,990 1,375 1,375 16 0.00 459.00 36 540 9.00 1.7 0.152 0.284 0.133 0.02 1.64 1,477 1,493 66,006 1,375 1,375 118 0.00 459.00 37 555 9.25 1.9 0.169 0.280 0.149 0.02 1.83 1,651 1,769 66,051 1,376 1,376 393 0.01 459.01 38 570 9.50 2.0 0.178 0.276 0.157 0.02 1.93 1,738 2,130 66,109 1,377 1,377 753 0.02 459.01 39 585 9.75 2.1 0.187 0.272 0.165 0.02 2.03 1,825 2,578 66,181 1,379 1,379 1,199 0.03 459.02 40 600 10.00 2.2 0.196 0.268 0.172 0.02 2.12 1,912 3,111 66,268 1,381 1,381 1,730 0.04 459.02 41 615 10.25 1.5 0.134 0.264 0.118 0.02 1.45 1,303 3,034 66,255 1,380 1,380 1,653 0.04 459.02 42 630 10.50 1.5 0.134 0.261 0.118 0.02 1.45 1,303 2,957 66,243 1,380 1,380 1,577 0.04 459.02 43 645 10.75 2.0 0.178 0.257 0.157 0.02 1.93 1,738 3,315 66,301 1,381 1,381 1,933 0.04 459.03 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 88.41 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.13 LAG TIME - MINUTES 2.46 C 0.00234 Maxwell Drywells UNIT TIME-PERCENT OF LAG 611%Low Loss Rate (percent)87.86%Number 0 TOTAL ADJUSTED STORM RAIN (in)2.23 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 44 660 11.00 2.0 0.178 0.253 0.157 0.02 1.93 1,738 3,671 66,358 1,382 1,382 2,289 0.05 459.03 45 675 11.25 1.9 0.169 0.249 0.149 0.02 1.83 1,651 3,940 66,402 1,383 1,383 2,556 0.06 459.04 46 690 11.50 1.9 0.169 0.246 0.149 0.02 1.83 1,651 4,207 66,445 1,384 1,384 2,823 0.06 459.04 47 705 11.75 1.7 0.152 0.242 0.133 0.02 1.64 1,477 4,300 66,460 1,385 1,385 2,916 0.07 459.04 48 720 12.00 1.8 0.161 0.238 0.141 0.02 1.74 1,564 4,480 66,489 1,385 1,385 3,095 0.07 459.04 49 735 12.25 2.5 0.223 0.235 0.196 0.03 2.41 2,172 5,267 66,616 1,388 1,388 3,879 0.09 459.05 50 750 12.50 2.6 0.232 0.231 0.204 0.00 0.06 54 3,933 66,400 1,383 1,383 2,550 0.06 459.04 51 765 12.75 2.8 0.250 0.228 0.219 0.02 1.96 1,764 4,313 66,462 1,385 1,385 2,929 0.07 459.04 52 780 13.00 2.9 0.259 0.224 0.227 0.03 3.06 2,755 5,684 66,683 1,389 1,389 4,295 0.10 459.06 53 795 13.25 3.4 0.303 0.221 0.266 0.08 7.34 6,606 10,900 67,526 1,407 1,407 9,493 0.22 459.13 54 810 13.50 3.4 0.303 0.218 0.266 0.09 7.64 6,874 16,368 68,409 1,425 1,425 14,942 0.34 459.21 55 825 13.75 2.3 0.205 0.214 0.180 0.02 2.22 1,999 16,941 68,502 1,427 1,427 15,514 0.36 459.22 56 840 14.00 2.3 0.205 0.211 0.180 0.02 2.22 1,999 17,512 68,594 1,429 1,429 16,083 0.37 459.23 57 855 14.25 2.7 0.241 0.208 0.212 0.03 2.94 2,649 18,733 68,791 1,433 1,433 17,300 0.40 459.24 58 870 14.50 2.6 0.232 0.205 0.204 0.03 2.43 2,188 19,488 68,913 1,436 1,436 18,052 0.41 459.25 59 885 14.75 2.6 0.232 0.202 0.204 0.03 2.71 2,439 20,492 69,076 1,439 1,439 19,053 0.44 459.27 60 900 15.00 2.5 0.223 0.198 0.196 0.02 2.19 1,971 21,024 69,162 1,441 1,441 19,583 0.45 459.27 61 915 15.25 2.4 0.214 0.195 0.188 0.02 1.67 1,499 21,082 69,171 1,441 1,441 19,641 0.45 459.27 62 930 15.50 2.3 0.205 0.192 0.180 0.01 1.14 1,023 20,664 69,103 1,440 1,440 19,224 0.44 459.27 63 945 15.75 1.9 0.169 0.189 0.149 0.02 1.83 1,651 20,875 69,138 1,440 1,440 19,435 0.45 459.27 64 960 16.00 1.9 0.169 0.187 0.149 0.02 1.83 1,651 21,086 69,172 1,441 1,441 19,645 0.45 459.27 65 975 16.25 0.4 0.036 0.184 0.031 0.00 0.39 348 19,992 68,995 1,437 1,437 18,555 0.43 459.26 66 990 16.50 0.4 0.036 0.181 0.031 0.00 0.39 348 18,902 68,819 1,434 1,434 17,469 0.40 459.24 67 1005 16.75 0.3 0.027 0.178 0.024 0.00 0.29 261 17,729 68,629 1,430 1,430 16,300 0.37 459.23 68 1020 17.00 0.3 0.027 0.175 0.024 0.00 0.29 261 16,560 68,440 1,426 1,426 15,134 0.35 459.21 69 1035 17.25 0.5 0.045 0.173 0.039 0.01 0.48 434 15,569 68,280 1,423 1,423 14,146 0.32 459.20 70 1050 17.50 0.5 0.045 0.170 0.039 0.01 0.48 434 14,581 68,121 1,419 1,419 13,162 0.30 459.18 71 1065 17.75 0.5 0.045 0.168 0.039 0.01 0.48 434 13,596 67,962 1,416 1,416 12,180 0.28 459.17 72 1080 18.00 0.4 0.036 0.165 0.031 0.00 0.39 348 12,528 67,789 1,412 1,412 11,116 0.26 459.16 73 1095 18.25 0.4 0.036 0.163 0.031 0.00 0.39 348 11,463 67,617 1,409 1,409 10,055 0.23 459.14 74 1110 18.50 0.4 0.036 0.160 0.031 0.00 0.39 348 10,402 67,446 1,405 1,405 8,997 0.21 459.13 75 1125 18.75 0.3 0.027 0.158 0.024 0.00 0.29 261 9,258 67,261 1,401 1,401 7,856 0.18 459.11 76 1140 19.00 0.2 0.018 0.156 0.016 0.00 0.19 174 8,030 67,062 1,397 1,397 6,633 0.15 459.09 77 1155 19.25 0.3 0.027 0.154 0.024 0.00 0.29 261 6,894 66,879 1,393 1,393 5,500 0.13 459.08 78 1170 19.50 0.4 0.036 0.152 0.031 0.00 0.39 348 5,848 66,710 1,390 1,390 4,458 0.10 459.06 79 1185 19.75 0.3 0.027 0.149 0.024 0.00 0.29 261 4,719 66,527 1,386 1,386 3,333 0.08 459.05 80 1200 20.00 0.2 0.018 0.147 0.016 0.00 0.19 174 3,507 66,332 1,382 1,382 2,125 0.05 459.03 81 1215 20.25 0.3 0.027 0.145 0.024 0.00 0.29 261 2,386 66,150 1,378 1,378 1,007 0.02 459.01 82 1230 20.50 0.3 0.027 0.144 0.024 0.00 0.29 261 1,268 65,970 1,374 1,268 0 0.00 459.00 83 1245 20.75 0.3 0.027 0.142 0.024 0.00 0.29 261 261 65,807 1,371 261 0 0.00 459.00 84 1260 21.00 0.2 0.018 0.140 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 85 1275 21.25 0.3 0.027 0.138 0.024 0.00 0.29 261 261 65,807 1,371 261 0 0.00 459.00 86 1290 21.50 0.2 0.018 0.137 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 88.41 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.13 LAG TIME - MINUTES 2.46 C 0.00234 Maxwell Drywells UNIT TIME-PERCENT OF LAG 611%Low Loss Rate (percent)87.86%Number 0 TOTAL ADJUSTED STORM RAIN (in)2.23 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 87 1305 21.75 0.3 0.027 0.135 0.024 0.00 0.29 261 261 65,807 1,371 261 0 0.00 459.00 88 1320 22.00 0.2 0.018 0.134 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 89 1335 22.25 0.3 0.027 0.133 0.024 0.00 0.29 261 261 65,807 1,371 261 0 0.00 459.00 90 1350 22.50 0.2 0.018 0.131 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 91 1365 22.75 0.2 0.018 0.130 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 92 1380 23.00 0.2 0.018 0.129 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 93 1395 23.25 0.2 0.018 0.128 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 94 1410 23.50 0.2 0.018 0.128 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 95 1425 23.75 0.2 0.018 0.127 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 96 1440 24.00 0.2 0.018 0.126 0.016 0.00 0.19 174 174 65,793 1,371 174 0 0.00 459.00 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 2.23 in 715,689 cu-ft 625,214 cu-ft 459.27 ft 7.64 cfs 90,475 cu-ft 62.83 cf/min 0.28 in 2.08 acft 90,475 cu-ft 0.45 acft 19,645 cu-ft Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 459 0 0 65,765 0 0 0.00 460 1 1 11,545 77,310 71,460 71,460 1.64 461 1 2 12,170 89,480 83,321 154,781 3.55 WHERE: TOTAL 10 YEAR BASIN BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2553 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 2 B PAVING/HARDSCAPE 2.071 D 56 0.51 1.00 1 B COMMERCIAL 5.752 D 56 0.51 0.90 6 B SF - HIGH DENSITY 8.141 D 56 0.51 0.50 9 B LANDSCAPING 1.350 D 56 0.51 0.10 1,260 ft 630 ft 465.3 ft ELEVATION OF CONCENTRATION POINT 458.0 ft 0.02 10 LOW LOSS RATE (For Storms Greater Than 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 0.71 in 3-HOUR 1.06 in 6-HOUR 1.36 in 24-HOUR 2.23 in ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) AMC NUMBER LENGTH OF WATERCOURSE (L) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME March 30, 2020 PROJECT NUMBER CONCENTRATION POINT DESIGNATION DATE: AREA DESIGNATION CORAL MOUNTAIN REQUIRED 10 YEAR STORAGE DA-A2 PROJECT: Job No.: BY:DATE:3/30/20 [1] AMC [2] FREQUENCY-YEARS NOAA ATLAS [3] DURATION: 1-HOUR 3-HOUR 6-HOUR 24-HOUR DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR TOTAL RAINFALL (in)0.71 1.06 1.36 2.23 RAINFALL VOLUME (cuft)44,624 66,621 85,476 140,156 SOIL LOSSES (cuft)12,970 32,123 39,734 73,692 EFFECTIVE RAIN (in)0.50 0.55 0.73 1.06 FLOOD VOLUME (cu-ft)31,653 34,498 45,742 66,464 (acre-ft)0.73 0.79 1.05 1.53 PEAK FLOW (cfs)N/A 14.61 12.35 2.19 RAINFALL DATA [18] 200% OF LAG-MINUTES STORM EVENT SUMMARY 7.8 II 10 14 Point Rain 0.71 in 1.06 in 1.36 in 2.23 in [8] ELEVATION OF HEADWATER 0.005 630.00 [12] S^0.5 0.119 0.02 [17] 100% OF LAG-MINUTES 3.9 3.9 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.06 [16] LAG TIME-MINUTES 1260 DLS 0.239 465.3 458 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD REQUIRED 10 YEAR STORAGE DA-A2 CORAL MOUNTAIN [2] AREA DESIGNATION HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. 17.314 PHYSICAL DATA [1] CONCENTRATION POINT [10] H-FEET 30.6 [3] AREA - ACRES [4] L-FEET [5] L-MILES [13] L*LCA/S^0.5 5.53 [11] S-FEET/MILE [6] La-FEET [7] La-MILES 7.3 [9] ELEVATION OF CONCENTRATION POINT Plate E-2.1 Page 2 of 9 PROJECT: Job No.: BY:DATE:3/30/20 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 100%0.05 2.071 0.120 0.0061 DEVELOPED 0.1000 0.0120 B 56 0.51 90%0.10 5.752 0.332 0.0322 DEVELOPED 0.1800 0.0598 B 56 0.51 50%0.28 8.141 0.470 0.1319 DEVELOPED 0.5000 0.2351 B 56 0.51 10%0.46 1.350 0.078 0.0362 DEVELOPED 0.8200 0.0639 SUM 17.314 SUM 0.2064 0.3708 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.10318457 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00191 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55 =0.00191 0.10 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.2064 in/hr Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.3708 in/hr Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AMC II AVERAGE ADJUSTED LOSS RATE (24-(T/60))^1.55 + LAND USE PAVING/HARDSCAPE COMMERCIAL SF - HIGH DENSITY LANDSCAPING CORAL MOUNTAIN DLS 2553 RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM Plate E-2.1 Page 3 of 9 PROJECT: Job No.:2553 DATE BY:DLS 3/30/20 DRAINAGE AREA-ACRES 17.31 UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.89 UNIT TIME-PERCENT OF LAG 128.6 TOTAL ADJUSTED STORM RAIN-INCHES 0.71 CONSTANT LOSS RATE-in/hr 0.21 LOW LOSS RATE - PERCENT 37% Unit Time Pattern Storm Effective Flood Period Minutes Hours Percent Rain Rain Hydrograph in/hr Flow (Plate E-5.9)Max Low in/hr cfs 1 5 0.08 3.6 0.31 0.21 0.11 0.10 1.75 2 10 0.17 4.2 0.36 0.21 0.13 0.15 2.64 3 15 0.25 4.4 0.37 0.21 0.14 0.17 2.94 4 20 0.33 4.6 0.39 0.21 0.15 0.19 3.24 5 25 0.42 5.0 0.43 0.21 0.16 0.22 3.83 6 30 0.50 5.6 0.48 0.21 0.18 0.27 4.73 7 35 0.58 6.4 0.55 0.21 0.20 0.34 5.92 8 40 0.67 8.1 0.69 0.21 0.26 0.48 8.45 9 45 0.75 13.1 1.12 0.21 0.41 0.91 15.88 10 50 0.83 34.5 2.94 0.21 1.09 2.73 47.71 11 55 0.92 6.7 0.57 0.21 0.21 0.36 6.36 12 60 1.00 3.8 0.32 0.21 0.12 0.12 2.05 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL (in)0.71 RAINFALL VOLUME (cuft)44,624 SOIL LOSSES (cuft)12,970 EFFECTIVE RAIN (in)0.50 FLOOD VOLUME (acft)0.73 FLOOD VOLUME (cuft)31,653 PEAK FLOW RATE (cfs)47.71 in/hr MANUAL 1-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 1 Hour Storm Page 4 of 9 PROJECT: Job No.:2553 DATE BY:DLS 3/30/20 DRAINAGE AREA-ACRES 17.31 UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.89 UNIT TIME-PERCENT OF LAG 128.6 TOTAL ADJUSTED STORM RAIN-INCHES 1.06 CONSTANT LOSS RATE-in/hr 0.21 LOW LOSS RATE - PERCENT 37% Unit Time Pattern Storm Effective Flood Period Minutes Hours Percent Rain Rain Hydrograph in/hr Flow (Plate E-5.9)Max Low in/hr cfs 1 5 0.08 1.3 0.17 0.21 0.06 0.10 1.82 2 10 0.17 1.3 0.17 0.21 0.06 0.10 1.82 3 15 0.25 1.1 0.14 0.21 0.05 0.09 1.54 4 20 0.33 1.5 0.19 0.21 0.07 0.12 2.10 5 25 0.42 1.5 0.19 0.21 0.07 0.12 2.10 6 30 0.50 1.8 0.23 0.21 0.08 0.02 0.39 7 35 0.58 1.5 0.19 0.21 0.07 0.12 2.10 8 40 0.67 1.8 0.23 0.21 0.08 0.02 0.39 9 45 0.75 1.8 0.23 0.21 0.08 0.02 0.39 10 50 0.83 1.5 0.19 0.21 0.07 0.12 2.10 11 55 0.92 1.6 0.20 0.21 0.08 0.13 2.24 12 60 1.00 1.8 0.23 0.21 0.08 0.02 0.39 13 65 1.08 2.2 0.28 0.21 0.10 0.07 1.28 14 70 1.17 2.2 0.28 0.21 0.10 0.07 1.28 15 75 1.25 2.2 0.28 0.21 0.10 0.07 1.28 16 80 1.33 2.0 0.25 0.21 0.09 0.05 0.84 17 85 1.42 2.6 0.33 0.21 0.12 0.12 2.17 18 90 1.50 2.7 0.34 0.21 0.13 0.14 2.39 19 95 1.58 2.4 0.31 0.21 0.11 0.10 1.73 20 100 1.67 2.7 0.34 0.21 0.13 0.14 2.39 21 105 1.75 3.3 0.42 0.21 0.16 0.21 3.73 22 110 1.83 3.1 0.39 0.21 0.15 0.19 3.28 23 115 1.92 2.9 0.37 0.21 0.14 0.16 2.84 24 120 2.00 3.0 0.38 0.21 0.14 0.18 3.06 25 125 2.08 3.1 0.39 0.21 0.15 0.19 3.28 26 130 2.17 4.2 0.53 0.21 0.20 0.33 5.72 27 135 2.25 5.0 0.64 0.21 0.24 0.43 7.50 28 140 2.33 3.5 0.45 0.21 0.17 0.24 4.17 29 145 2.42 6.8 0.86 0.21 0.32 0.66 11.50 30 150 2.50 7.3 0.93 0.21 0.34 0.72 12.61 31 155 2.58 8.2 1.04 0.21 0.39 0.84 14.61 32 160 2.67 5.9 0.75 0.21 0.28 0.54 9.50 33 165 2.75 2.0 0.25 0.21 0.09 0.05 0.84 34 170 2.83 1.8 0.23 0.21 0.08 0.02 0.39 35 175 2.92 1.8 0.23 0.21 0.08 0.02 0.39 36 180 3.00 0.6 0.08 0.21 0.03 0.05 0.84 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL (in)1.06 RAINFALL VOLUME (cuft)66,621 SOIL LOSSES (cuft)32,123 EFFECTIVE RAIN (in)0.55 FLOOD VOLUME (acft)0.79 FLOOD VOLUME (cuft)34,498 PEAK FLOW RATE (cfs)14.61 Loss Rate in/hr Time UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM CORAL MOUNTAIN MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 3-HOUR STORM RCFC & WCD HYDROLOGY Plate E-2.2 3-Hour Storm Page 5 of 9 PROJECT: Job No.:2553 DATE BY:DLS 3/30/20 DRAINAGE AREA-ACRES 17.31 UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.89 UNIT TIME-PERCENT OF LAG 128.6 TOTAL ADJUSTED STORM RAIN-INCHES 1.36 CONSTANT LOSS RATE-in/hr 0.206 LOW LOSS RATE - PERCENT 37% Unit Time Pattern Storm Effective Flood Period Minutes Hours Percent Rain Rain Hydrograph in/hr Flow (Plate E-5.9)Max Low in/hr cfs 1 5 0.08 0.5 0.082 0.21 0.03 0.05 0.90 2 10 0.17 0.6 0.098 0.21 0.04 0.06 1.08 3 15 0.25 0.6 0.098 0.21 0.04 0.06 1.08 4 20 0.33 0.6 0.098 0.21 0.04 0.06 1.08 5 25 0.42 0.6 0.098 0.21 0.04 0.06 1.08 6 30 0.50 0.7 0.114 0.21 0.04 0.07 1.25 7 35 0.58 0.7 0.114 0.21 0.04 0.07 1.25 8 40 0.67 0.7 0.114 0.21 0.04 0.07 1.25 9 45 0.75 0.7 0.114 0.21 0.04 0.07 1.25 10 50 0.83 0.7 0.114 0.21 0.04 0.07 1.25 11 55 0.92 0.7 0.114 0.21 0.04 0.07 1.25 12 60 1.00 0.8 0.131 0.21 0.05 0.08 1.43 13 65 1.08 0.8 0.131 0.21 0.05 0.08 1.43 14 70 1.17 0.8 0.131 0.21 0.05 0.08 1.43 15 75 1.25 0.8 0.131 0.21 0.05 0.08 1.43 16 80 1.33 0.8 0.131 0.21 0.05 0.08 1.43 17 85 1.42 0.8 0.131 0.21 0.05 0.08 1.43 18 90 1.50 0.8 0.131 0.21 0.05 0.08 1.43 19 95 1.58 0.8 0.131 0.21 0.05 0.08 1.43 20 100 1.67 0.8 0.131 0.21 0.05 0.08 1.43 21 105 1.75 0.8 0.131 0.21 0.05 0.08 1.43 22 110 1.83 0.8 0.131 0.21 0.05 0.08 1.43 23 115 1.92 0.8 0.131 0.21 0.05 0.08 1.43 24 120 2.00 0.9 0.147 0.21 0.05 0.09 1.61 25 125 2.08 0.8 0.131 0.21 0.05 0.08 1.43 26 130 2.17 0.9 0.147 0.21 0.05 0.09 1.61 27 135 2.25 0.9 0.147 0.21 0.05 0.09 1.61 28 140 2.33 0.9 0.147 0.21 0.05 0.09 1.61 29 145 2.42 0.9 0.147 0.21 0.05 0.09 1.61 30 150 2.50 0.9 0.147 0.21 0.05 0.09 1.61 31 155 2.58 0.9 0.147 0.21 0.05 0.09 1.61 32 160 2.67 0.9 0.147 0.21 0.05 0.09 1.61 33 165 2.75 1.0 0.163 0.21 0.06 0.10 1.79 34 170 2.83 1.0 0.163 0.21 0.06 0.10 1.79 35 175 2.92 1.0 0.163 0.21 0.06 0.10 1.79 36 180 3.00 1.0 0.163 0.21 0.06 0.10 1.79 37 185 3.08 1.0 0.163 0.21 0.06 0.10 1.79 38 190 3.17 1.1 0.180 0.21 0.07 0.11 1.97 39 195 3.25 1.1 0.180 0.21 0.07 0.11 1.97 40 200 3.33 1.1 0.180 0.21 0.07 0.11 1.97 41 205 3.42 1.2 0.196 0.21 0.07 0.12 2.15 42 210 3.50 1.3 0.212 0.21 0.08 0.01 0.10 43 215 3.58 1.4 0.228 0.21 0.08 0.02 0.39 44 220 3.67 1.4 0.228 0.21 0.08 0.02 0.39 45 225 3.75 1.5 0.245 0.21 0.09 0.04 0.67 46 230 3.83 1.5 0.245 0.21 0.09 0.04 0.67 47 235 3.92 1.6 0.261 0.21 0.10 0.05 0.96 48 240 4.00 1.6 0.261 0.21 0.10 0.05 0.96 49 245 4.08 1.7 0.277 0.21 0.10 0.07 1.24 50 250 4.17 1.8 0.294 0.21 0.11 0.09 1.53 51 255 4.25 1.9 0.310 0.21 0.11 0.10 1.81 52 260 4.33 2.0 0.326 0.21 0.12 0.12 2.10 53 265 4.42 2.1 0.343 0.21 0.13 0.14 2.38 54 270 4.50 2.1 0.343 0.21 0.13 0.14 2.38 UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate in/hr MANUAL 6-HOUR STORM CORAL MOUNTAINRCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD HYDROLOGY SHORTCUT METHOD Plate E-2.2 6-Hour Storm Page 6 of 9 PROJECT: Job No.:2553 DATE BY:DLS 3/30/20 DRAINAGE AREA-ACRES 17.31 UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.89 UNIT TIME-PERCENT OF LAG 128.6 TOTAL ADJUSTED STORM RAIN-INCHES 1.36 CONSTANT LOSS RATE-in/hr 0.206 LOW LOSS RATE - PERCENT 37% Unit Time Pattern Storm Effective Flood Period Minutes Hours Percent Rain Rain Hydrograph in/hr Flow (Plate E-5.9)Max Low in/hr cfs UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate in/hr MANUAL 6-HOUR STORM CORAL MOUNTAINRCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD HYDROLOGY SHORTCUT METHOD 55 275 4.58 2.2 0.359 0.21 0.13 0.15 2.67 56 280 4.67 2.3 0.375 0.21 0.14 0.17 2.95 57 285 4.75 2.4 0.392 0.21 0.15 0.19 3.24 58 290 4.83 2.4 0.392 0.21 0.15 0.19 3.24 59 295 4.92 2.5 0.408 0.21 0.15 0.20 3.52 60 300 5.00 2.6 0.424 0.21 0.16 0.22 3.81 61 305 5.08 3.1 0.506 0.21 0.19 0.30 5.23 62 310 5.17 3.6 0.588 0.21 0.22 0.38 6.65 63 315 5.25 3.9 0.636 0.21 0.24 0.43 7.51 64 320 5.33 4.2 0.685 0.21 0.25 0.48 8.36 65 325 5.42 4.7 0.767 0.21 0.28 0.56 9.79 66 330 5.50 5.6 0.914 0.21 0.34 0.71 12.35 67 335 5.58 1.9 0.310 0.21 0.11 0.10 1.81 68 340 5.67 0.9 0.147 0.21 0.05 0.09 1.61 69 345 5.75 0.6 0.098 0.21 0.04 0.06 1.08 70 350 5.83 0.5 0.082 0.21 0.03 0.05 0.90 71 355 5.92 0.3 0.049 0.21 0.02 0.03 0.54 72 360 6.00 0.2 0.033 0.21 0.01 0.02 0.36 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL (in)1.36 RAINFALL VOLUME (cuft)85,476 SOIL LOSSES (cuft)39,734 EFFECTIVE RAIN (in)0.73 FLOOD VOLUME (acft)1.05 FLOOD VOLUME (cuft)45,742 PEAK FLOW RATE (cfs)12.35 Plate E-2.2 6-Hour Storm Page 7 of 9 PROJECT: Job No.:2553 DATE: BY:DLS 3/30/20 DRAINAGE AREA-ACRES 17.314 CONSTANT LOSS RATE-in/hr n/a UNIT TIME-MINUTES 15 VARIABLE LOSS RATE (AVG) in/hr 0.2064 LAG TIME - MINUTES 3.89 MINIMUM LOSS RATE (for var. loss) - in/hr 0.103 UNIT TIME-PERCENT OF LAG 385.7 LOW LOSS RATE - DECIMAL 0.37 TOTAL ADJUSTED STORM RAIN-INCHES 2.23 C 0.00191 Unit Time Pattern Storm Effective Flood Period Minutes Hours Percent Rain Rain Hydrograph in/hr Flow (Plate E-5.9)Max Low in/hr cfs 1 15 0.25 0.2 0.018 0.364 0.007 0.011 0.20 2 30 0.50 0.3 0.027 0.360 0.010 0.017 0.29 3 45 0.75 0.3 0.027 0.356 0.010 0.017 0.29 4 60 1.00 0.4 0.036 0.352 0.013 0.022 0.39 5 75 1.25 0.3 0.027 0.348 0.010 0.017 0.29 6 90 1.50 0.3 0.027 0.344 0.010 0.017 0.29 7 105 1.75 0.3 0.027 0.339 0.010 0.017 0.29 8 120 2.00 0.4 0.036 0.335 0.013 0.022 0.39 9 135 2.25 0.4 0.036 0.331 0.013 0.022 0.39 10 150 2.50 0.4 0.036 0.327 0.013 0.022 0.39 11 165 2.75 0.5 0.045 0.323 0.017 0.028 0.49 12 180 3.00 0.5 0.045 0.319 0.017 0.028 0.49 13 195 3.25 0.5 0.045 0.315 0.017 0.028 0.49 14 210 3.50 0.5 0.045 0.311 0.017 0.028 0.49 15 225 3.75 0.5 0.045 0.308 0.017 0.028 0.49 16 240 4.00 0.6 0.054 0.304 0.020 0.034 0.59 17 255 4.25 0.6 0.054 0.300 0.020 0.034 0.59 18 270 4.50 0.7 0.062 0.296 0.023 0.039 0.69 19 285 4.75 0.7 0.062 0.292 0.023 0.039 0.69 20 300 5.00 0.8 0.071 0.288 0.026 0.045 0.78 21 315 5.25 0.6 0.054 0.285 0.020 0.034 0.59 22 330 5.50 0.7 0.062 0.281 0.023 0.039 0.69 23 345 5.75 0.8 0.071 0.277 0.026 0.045 0.78 24 360 6.00 0.8 0.071 0.274 0.026 0.045 0.78 25 375 6.25 0.9 0.080 0.270 0.030 0.051 0.88 26 390 6.50 0.9 0.080 0.266 0.030 0.051 0.88 27 405 6.75 1.0 0.089 0.263 0.033 0.056 0.98 28 420 7.00 1.0 0.089 0.259 0.033 0.056 0.98 29 435 7.25 1.0 0.089 0.256 0.033 0.056 0.98 30 450 7.50 1.1 0.098 0.252 0.036 0.062 1.08 31 465 7.75 1.2 0.107 0.249 0.040 0.067 1.18 32 480 8.00 1.3 0.116 0.245 0.043 0.073 1.27 33 495 8.25 1.5 0.134 0.242 0.050 0.084 1.47 34 510 8.50 1.5 0.134 0.239 0.050 0.084 1.47 35 525 8.75 1.6 0.143 0.235 0.053 0.090 1.57 36 540 9.00 1.7 0.152 0.232 0.056 0.095 1.67 37 555 9.25 1.9 0.169 0.229 0.063 0.107 1.86 38 570 9.50 2.0 0.178 0.225 0.066 0.112 1.96 39 585 9.75 2.1 0.187 0.222 0.069 0.118 2.06 40 600 10.00 2.2 0.196 0.219 0.073 0.123 2.16 41 615 10.25 1.5 0.134 0.216 0.050 0.084 1.47 42 630 10.50 1.5 0.134 0.213 0.050 0.084 1.47 43 645 10.75 2.0 0.178 0.210 0.066 0.112 1.96 44 660 11.00 2.0 0.178 0.207 0.066 0.112 1.96 45 675 11.25 1.9 0.169 0.203 0.063 0.107 1.86 46 690 11.50 1.9 0.169 0.200 0.063 0.107 1.86 47 705 11.75 1.7 0.152 0.198 0.056 0.095 1.67 48 720 12.00 1.8 0.161 0.195 0.060 0.101 1.76 49 735 12.25 2.5 0.223 0.192 0.083 0.031 0.55 50 750 12.50 2.6 0.232 0.189 0.086 0.043 0.75 51 765 12.75 2.8 0.250 0.186 0.093 0.064 1.11 52 780 13.00 2.9 0.259 0.183 0.096 0.076 1.32 53 795 13.25 3.4 0.303 0.180 0.112 0.123 2.15 54 810 13.50 3.4 0.303 0.178 0.112 0.126 2.19 55 825 13.75 2.3 0.205 0.175 0.076 0.030 0.53 56 840 14.00 2.3 0.205 0.172 0.076 0.033 0.57 57 855 14.25 2.7 0.241 0.170 0.089 0.071 1.24 58 870 14.50 2.6 0.232 0.167 0.086 0.065 1.13 59 885 14.75 2.6 0.232 0.165 0.086 0.067 1.18 60 900 15.00 2.5 0.223 0.162 0.083 0.061 1.06 61 915 15.25 2.4 0.214 0.160 0.079 0.055 0.95 62 930 15.50 2.3 0.205 0.157 0.076 0.048 0.84 63 945 15.75 1.9 0.169 0.155 0.063 0.015 0.26 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD in/hr UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Time Loss Rate MANUAL 24-HOUR STORM Plate E-2.2 24 Hour Storm Page 8 of 9 PROJECT: Job No.:2553 DATE: BY:DLS 3/30/20 DRAINAGE AREA-ACRES 17.314 CONSTANT LOSS RATE-in/hr n/a UNIT TIME-MINUTES 15 VARIABLE LOSS RATE (AVG) in/hr 0.2064 LAG TIME - MINUTES 3.89 MINIMUM LOSS RATE (for var. loss) - in/hr 0.103 UNIT TIME-PERCENT OF LAG 385.7 LOW LOSS RATE - DECIMAL 0.37 TOTAL ADJUSTED STORM RAIN-INCHES 2.23 C 0.00191 Unit Time Pattern Storm Effective Flood Period Minutes Hours Percent Rain Rain Hydrograph in/hr Flow (Plate E-5.9)Max Low in/hr cfs RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD in/hr UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Time Loss Rate MANUAL 24-HOUR STORM 64 960 16.00 1.9 0.169 0.152 0.063 0.017 0.30 65 975 16.25 0.4 0.036 0.150 0.013 0.022 0.39 66 990 16.50 0.4 0.036 0.148 0.013 0.022 0.39 67 1005 16.75 0.3 0.027 0.145 0.010 0.017 0.29 68 1020 17.00 0.3 0.027 0.143 0.010 0.017 0.29 69 1035 17.25 0.5 0.045 0.141 0.017 0.028 0.49 70 1050 17.50 0.5 0.045 0.139 0.017 0.028 0.49 71 1065 17.75 0.5 0.045 0.137 0.017 0.028 0.49 72 1080 18.00 0.4 0.036 0.135 0.013 0.022 0.39 73 1095 18.25 0.4 0.036 0.133 0.013 0.022 0.39 74 1110 18.50 0.4 0.036 0.131 0.013 0.022 0.39 75 1125 18.75 0.3 0.027 0.129 0.010 0.017 0.29 76 1140 19.00 0.2 0.018 0.127 0.007 0.011 0.20 77 1155 19.25 0.3 0.027 0.125 0.010 0.017 0.29 78 1170 19.50 0.4 0.036 0.124 0.013 0.022 0.39 79 1185 19.75 0.3 0.027 0.122 0.010 0.017 0.29 80 1200 20.00 0.2 0.018 0.120 0.007 0.011 0.20 81 1215 20.25 0.3 0.027 0.119 0.010 0.017 0.29 82 1230 20.50 0.3 0.027 0.117 0.010 0.017 0.29 83 1245 20.75 0.3 0.027 0.116 0.010 0.017 0.29 84 1260 21.00 0.2 0.018 0.114 0.007 0.011 0.20 85 1275 21.25 0.3 0.027 0.113 0.010 0.017 0.29 86 1290 21.50 0.2 0.018 0.112 0.007 0.011 0.20 87 1305 21.75 0.3 0.027 0.110 0.010 0.017 0.29 88 1320 22.00 0.2 0.018 0.109 0.007 0.011 0.20 89 1335 22.25 0.3 0.027 0.108 0.010 0.017 0.29 90 1350 22.50 0.2 0.018 0.107 0.007 0.011 0.20 91 1365 22.75 0.2 0.018 0.106 0.007 0.011 0.20 92 1380 23.00 0.2 0.018 0.105 0.007 0.011 0.20 93 1395 23.25 0.2 0.018 0.105 0.007 0.011 0.20 94 1410 23.50 0.2 0.018 0.104 0.007 0.011 0.20 95 1425 23.75 0.2 0.018 0.104 0.007 0.011 0.20 96 1440 24.00 0.2 0.018 0.103 0.007 0.011 0.20 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL (in)2.23 RAINFALL VOLUME (cuft)140,156 SOIL LOSSES (cuft)73,692 EFFECTIVE RAIN (in)1.06 FLOOD VOLUME (acft)1.53 FLOOD VOLUME (cuft)66,464 PEAK FLOW (cfs)2.19 Plate E-2.2 24 Hour Storm Page 9 of 9 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 11 D EXISTING BARREN 1.268 X 93 0.09 0.05 12 B EXISTING OPEN BRUSH - POOR 4.870 X 76 0.29 0.05 2 B PAVING/HARDSCAPE 0.011 D 56 0.51 1.00 3 B WATER FEATURE 0.000 D 56 0.51 1.00 1 B COMMERCIAL 0.000 D 56 0.51 0.90 6 B SF - HIGH DENSITY 0.000 D 56 0.51 0.50 9 B LANDSCAPING 18.819 D 56 0.51 0.10 1,050 ft 525 ft 520.0 ft ELEVATION OF CONCENTRATION POINT 472.0 ft 0.03 10 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 0.71 in 3-HOUR 1.06 in 6-HOUR 1.36 in 24-HOUR 2.23 in BASIN CHARACTERISTICS:ELEVATION AREA 468.0 ft 10,730 sf 469.0 ft 17,060 sf 470.0 ft 24,025 sf PERCOLATION RATE (in/hr)1.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 10 YEAR BASIN AMC NUMBER RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE March 30, 2020 CORAL MOUNTAIN LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-A3 Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:3/30/20 [1] AMC II [2] FREQUENCY-YEARS 10 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 0.71 in 3-HOUR 1.06 in 6-HOUR 1.36 in 24-HOUR 2.23 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)64,441 96,072 123,263 202,114 SOIL LOSSES (cu-ft)32,724 69,661 96,384 169,645 EFFECTIVE RAIN (in)0.35 0.29 0.30 0.36 FLOOD VOLUME (cu-ft)31,717 26,411 26,879 32,470 (acre-ft)0.73 0.61 0.62 0.75 REQUIRED STORAGE (cu-ft)30,493 23,026 20,546 14,184 (acre-ft)0.70 0.53 0.47 0.33 FACTOR OF SAFETY 1.12 1.49 1.67 2.41 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 15.98 12.73 1.23 MAXIMUM WSEL (ft)469.82 469.45 469.33 469.02 DEPTH (ft)1.82 1.45 1.33 1.02 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days)1.1 1.0 1.0 1.3 10 YEAR BASIN DA-A3 CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 24.968 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION [3] AREA - ACRES [4] L-FEET [5] L-MILES 1050 0.199 [13] L*LCA/S^0.5 15.54 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.001 525.00 [12] S^0.5 0.099 241.4 520 472 48 0.03 [17] 100% OF LAG-MINUTES 3.4 3.4 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.06 [16] LAG TIME-MINUTES [18] 200% OF LAG-MINUTES RAINFALL DATA 6.9 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 34,217 0.79 Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:3/30/20 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] D 93 0.09 5%0.09 1.268 0.051 0.0044 UNDEVELOPED 0.9000 0.0457 B 76 0.29 5%0.28 4.870 0.195 0.0540 UNDEVELOPED 0.9000 0.1755 B 56 0.51 100%0.05 0.011 0.000 0.0000 DEVELOPED 0.1000 0.0000 B 56 0.51 100%0.05 0.000 0.000 0.0000 DEVELOPED 0.1000 0.0000 B 56 0.51 90%0.10 0.000 0.000 0.0000 DEVELOPED 0.1800 0.0000 B 56 0.51 50%0.28 0.000 0.000 0.0000 DEVELOPED 0.5000 0.0000 B 56 0.51 10%0.46 18.819 0.754 0.3498 DEVELOPED 0.8200 0.6181 SUM 24.968 SUM 0.4082 0.8393 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.204105054 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00378 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00378 0.20 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.4082 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8393 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II (24-(T/60))^1.55 + LAND USE EXISTING BARREN EXISTING OPEN BRUSH - POOR PAVING/HARDSCAPE WATER FEATURE COMMERCIAL SF - HIGH DENSITY LANDSCAPING Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 24.97 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.43 Maxwell Drywells UNIT TIME-PERCENT OF LAG 145.8 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 0.71 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.41 LOW LOSS RATE - PERCENT 83.93% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.31 0.41 0.26 0.05 1.24 373 373 10,901 76 76 297 0.01 468.02 2 10 0.17 4.2 0.36 0.41 0.30 0.06 1.45 435 732 11,066 77 77 655 0.02 468.05 3 15 0.25 4.4 0.38 0.41 0.32 0.06 1.52 456 1,110 11,240 78 78 1,032 0.02 468.07 4 20 0.33 4.6 0.39 0.41 0.33 0.06 1.59 476 1,509 11,423 79 79 1,429 0.03 468.10 5 25 0.42 5.0 0.43 0.41 0.36 0.02 0.46 139 1,568 11,451 80 80 1,489 0.03 468.11 6 30 0.50 5.6 0.48 0.41 0.40 0.07 1.75 526 2,014 11,656 81 81 1,933 0.04 468.14 7 35 0.58 6.4 0.55 0.41 0.46 0.14 3.47 1,041 2,974 12,097 84 84 2,890 0.07 468.21 8 40 0.67 8.1 0.69 0.41 0.58 0.28 7.12 2,137 5,027 13,040 91 91 4,936 0.11 468.36 9 45 0.75 13.1 1.12 0.41 0.94 0.71 17.86 5,359 10,295 15,461 107 107 10,188 0.23 468.74 10 50 0.83 34.5 2.94 0.41 2.47 2.54 63.83 19,149 29,337 22,362 155 155 29,181 0.67 469.75 11 55 0.92 6.7 0.57 0.41 0.48 0.16 4.11 1,234 30,416 22,730 158 158 30,258 0.69 469.81 12 60 1.00 3.8 0.32 0.41 0.27 0.05 1.31 393 30,651 22,810 158 158 30,493 0.70 469.82 TOTAL RAINFALL 0.71 in RAINFALL VOLUME 64,441 cu-ft SOIL LOSSES 32,724 cu-ft EFFECTIVE RAIN 0.35 in FLOOD VOLUME 0.73 acft FLOOD VOLUME 31,717 cu-ft REQUIRED STORAGE 0.70 REQUIRED STORAGE 30,493 cu-ft MAX WSEL 469.82 ft PEAK FLOW RATE 63.83 cfs TOTAL BASIN LOSSES 1,224 cu-ft AVERAGE PERCOLATION RATE 20.40 cf/min CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 24.97 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.43 Maxwell Drywells UNIT TIME-PERCENT OF LAG 145.8 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.06 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.41 LOW LOSS RATE - PERCENT 83.93% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.17 0.41 0.14 0.03 0.67 201 201 10,822 75 75 125 0.00 468.01 2 10 0.17 1.3 0.17 0.41 0.14 0.03 0.67 201 326 10,880 76 76 251 0.01 468.02 3 15 0.25 1.1 0.14 0.41 0.12 0.02 0.57 170 420 10,923 76 76 344 0.01 468.03 4 20 0.33 1.5 0.19 0.41 0.16 0.03 0.77 232 576 10,995 76 76 500 0.01 468.04 5 25 0.42 1.5 0.19 0.41 0.16 0.03 0.77 232 731 11,066 77 77 654 0.02 468.05 6 30 0.50 1.8 0.23 0.41 0.19 0.04 0.93 278 932 11,158 77 77 855 0.02 468.06 7 35 0.58 1.5 0.19 0.41 0.16 0.03 0.77 232 1,086 11,229 78 78 1,008 0.02 468.07 8 40 0.67 1.8 0.23 0.41 0.19 0.04 0.93 278 1,286 11,321 79 79 1,207 0.03 468.09 9 45 0.75 1.8 0.23 0.41 0.19 0.04 0.93 278 1,485 11,413 79 79 1,406 0.03 468.10 10 50 0.83 1.5 0.19 0.41 0.16 0.03 0.77 232 1,637 11,483 80 80 1,558 0.04 468.11 11 55 0.92 1.6 0.20 0.41 0.17 0.03 0.82 247 1,805 11,559 80 80 1,724 0.04 468.13 12 60 1.00 1.8 0.23 0.41 0.19 0.04 0.93 278 2,002 11,650 81 81 1,921 0.04 468.14 13 65 1.08 2.2 0.28 0.41 0.23 0.04 1.13 340 2,261 11,769 82 82 2,179 0.05 468.16 14 70 1.17 2.2 0.28 0.41 0.23 0.04 1.13 340 2,519 11,888 83 83 2,436 0.06 468.18 15 75 1.25 2.2 0.28 0.41 0.23 0.04 1.13 340 2,776 12,006 83 83 2,692 0.06 468.20 16 80 1.33 2.0 0.25 0.41 0.21 0.04 1.03 309 3,001 12,109 84 84 2,917 0.07 468.21 17 85 1.42 2.6 0.33 0.41 0.28 0.05 1.34 401 3,318 12,255 85 85 3,233 0.07 468.23 18 90 1.50 2.7 0.34 0.41 0.29 0.06 1.39 417 3,650 12,407 86 86 3,564 0.08 468.26 19 95 1.58 2.4 0.31 0.41 0.26 0.05 1.23 370 3,934 12,538 87 87 3,847 0.09 468.28 20 100 1.67 2.7 0.34 0.41 0.29 0.06 1.39 417 4,264 12,690 88 88 4,176 0.10 468.30 21 105 1.75 3.3 0.42 0.41 0.35 0.01 0.29 87 4,263 12,689 88 88 4,175 0.10 468.30 22 110 1.83 3.1 0.39 0.41 0.33 0.06 1.59 478 4,653 12,869 89 89 4,564 0.10 468.33 23 115 1.92 2.9 0.37 0.41 0.31 0.06 1.49 448 5,011 13,033 91 91 4,921 0.11 468.36 24 120 2.00 3.0 0.38 0.41 0.32 0.06 1.54 463 5,384 13,204 92 92 5,292 0.12 468.38 25 125 2.08 3.1 0.39 0.41 0.33 0.06 1.59 478 5,771 13,382 93 93 5,678 0.13 468.41 Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 24.97 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.43 Maxwell Drywells UNIT TIME-PERCENT OF LAG 145.8 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.06 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.41 LOW LOSS RATE - PERCENT 83.93% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD 26 130 2.17 4.2 0.53 0.41 0.45 0.13 3.17 952 6,630 13,777 96 96 6,534 0.15 468.47 27 135 2.25 5.0 0.64 0.41 0.53 0.23 5.73 1,720 8,254 14,524 101 101 8,153 0.19 468.59 28 140 2.33 3.5 0.45 0.41 0.37 0.04 0.93 279 8,433 14,606 101 101 8,331 0.19 468.60 29 145 2.42 6.8 0.86 0.41 0.73 0.46 11.50 3,450 11,781 16,144 112 112 11,669 0.27 468.85 30 150 2.50 7.3 0.93 0.41 0.78 0.52 13.10 3,930 15,599 17,682 123 123 15,476 0.36 469.08 31 155 2.58 8.2 1.04 0.41 0.88 0.63 15.98 4,795 20,271 19,274 134 134 20,137 0.46 469.31 32 160 2.67 5.9 0.75 0.41 0.63 0.34 8.62 2,585 22,722 20,109 140 140 22,583 0.52 469.43 33 165 2.75 2.0 0.25 0.41 0.21 0.04 1.03 309 22,892 20,167 140 140 22,751 0.52 469.44 34 170 2.83 1.8 0.23 0.41 0.19 0.04 0.93 278 23,029 20,213 140 140 22,889 0.53 469.45 35 175 2.92 1.8 0.23 0.41 0.19 0.04 0.93 278 23,167 20,260 141 141 23,026 0.53 469.45 36 180 3.00 0.6 0.08 0.41 0.06 0.01 0.31 93 23,119 20,244 141 141 22,978 0.53 469.45 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 69,661 cu-ft 1.06 in 96,072 cu-ft 469.45 ft 15.98 cfs 3,433 cu-ft 19.07 cf/min 0.29 in 0.61 acft 26,411 cu-ft 0.53 acft 23,026 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 24.97 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.43 Maxwell Drywells UNIT TIME-PERCENT OF LAG 145.8 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.36 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.41 LOW LOSS RATE - PERCENT 83.93% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.08 0.41 0.07 0.01 0.33 99 99 10,776 75 75 24 0.00 468.00 2 10 0.17 0.6 0.10 0.41 0.08 0.02 0.40 119 143 10,796 75 75 68 0.00 468.00 3 15 0.25 0.6 0.10 0.41 0.08 0.02 0.40 119 187 10,816 75 75 112 0.00 468.01 4 20 0.33 0.6 0.10 0.41 0.08 0.02 0.40 119 231 10,836 75 75 155 0.00 468.01 5 25 0.42 0.6 0.10 0.41 0.08 0.02 0.40 119 274 10,856 75 75 199 0.00 468.01 6 30 0.50 0.7 0.11 0.41 0.10 0.02 0.46 139 337 10,885 76 76 262 0.01 468.02 7 35 0.58 0.7 0.11 0.41 0.10 0.02 0.46 139 400 10,914 76 76 325 0.01 468.02 8 40 0.67 0.7 0.11 0.41 0.10 0.02 0.46 139 463 10,943 76 76 387 0.01 468.03 9 45 0.75 0.7 0.11 0.41 0.10 0.02 0.46 139 526 10,972 76 76 450 0.01 468.03 10 50 0.83 0.7 0.11 0.41 0.10 0.02 0.46 139 588 11,000 76 76 512 0.01 468.04 11 55 0.92 0.7 0.11 0.41 0.10 0.02 0.46 139 650 11,029 77 77 574 0.01 468.04 12 60 1.00 0.8 0.13 0.41 0.11 0.02 0.53 158 732 11,067 77 77 655 0.02 468.05 13 65 1.08 0.8 0.13 0.41 0.11 0.02 0.53 158 814 11,104 77 77 737 0.02 468.05 14 70 1.17 0.8 0.13 0.41 0.11 0.02 0.53 158 895 11,141 77 77 818 0.02 468.06 15 75 1.25 0.8 0.13 0.41 0.11 0.02 0.53 158 976 11,179 78 78 899 0.02 468.07 16 80 1.33 0.8 0.13 0.41 0.11 0.02 0.53 158 1,057 11,216 78 78 979 0.02 468.07 17 85 1.42 0.8 0.13 0.41 0.11 0.02 0.53 158 1,138 11,253 78 78 1,059 0.02 468.08 18 90 1.50 0.8 0.13 0.41 0.11 0.02 0.53 158 1,218 11,290 78 78 1,139 0.03 468.08 19 95 1.58 0.8 0.13 0.41 0.11 0.02 0.53 158 1,298 11,326 79 79 1,219 0.03 468.09 20 100 1.67 0.8 0.13 0.41 0.11 0.02 0.53 158 1,378 11,363 79 79 1,299 0.03 468.09 21 105 1.75 0.8 0.13 0.41 0.11 0.02 0.53 158 1,457 11,400 79 79 1,378 0.03 468.10 22 110 1.83 0.8 0.13 0.41 0.11 0.02 0.53 158 1,536 11,436 79 79 1,457 0.03 468.11 23 115 1.92 0.8 0.13 0.41 0.11 0.02 0.53 158 1,615 11,472 80 80 1,536 0.04 468.11 24 120 2.00 0.9 0.15 0.41 0.12 0.02 0.59 178 1,714 11,518 80 80 1,634 0.04 468.12 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 24.97 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.43 Maxwell Drywells UNIT TIME-PERCENT OF LAG 145.8 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.36 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.41 LOW LOSS RATE - PERCENT 83.93% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.13 0.41 0.11 0.02 0.53 158 1,792 11,554 80 80 1,712 0.04 468.12 26 130 2.17 0.9 0.15 0.41 0.12 0.02 0.59 178 1,890 11,599 81 81 1,810 0.04 468.13 27 135 2.25 0.9 0.15 0.41 0.12 0.02 0.59 178 1,988 11,644 81 81 1,907 0.04 468.14 28 140 2.33 0.9 0.15 0.41 0.12 0.02 0.59 178 2,085 11,688 81 81 2,004 0.05 468.15 29 145 2.42 0.9 0.15 0.41 0.12 0.02 0.59 178 2,182 11,733 81 81 2,101 0.05 468.15 30 150 2.50 0.9 0.15 0.41 0.12 0.02 0.59 178 2,279 11,777 82 82 2,197 0.05 468.16 31 155 2.58 0.9 0.15 0.41 0.12 0.02 0.59 178 2,376 11,822 82 82 2,293 0.05 468.17 32 160 2.67 0.9 0.15 0.41 0.12 0.02 0.59 178 2,472 11,866 82 82 2,389 0.05 468.17 33 165 2.75 1.0 0.16 0.41 0.14 0.03 0.66 198 2,587 11,919 83 83 2,505 0.06 468.18 34 170 2.83 1.0 0.16 0.41 0.14 0.03 0.66 198 2,703 11,972 83 83 2,619 0.06 468.19 35 175 2.92 1.0 0.16 0.41 0.14 0.03 0.66 198 2,817 12,025 84 84 2,734 0.06 468.20 36 180 3.00 1.0 0.16 0.41 0.14 0.03 0.66 198 2,932 12,077 84 84 2,848 0.07 468.21 37 185 3.08 1.0 0.16 0.41 0.14 0.03 0.66 198 3,046 12,130 84 84 2,962 0.07 468.22 38 190 3.17 1.1 0.18 0.41 0.15 0.03 0.73 218 3,180 12,191 85 85 3,095 0.07 468.22 39 195 3.25 1.1 0.18 0.41 0.15 0.03 0.73 218 3,313 12,253 85 85 3,228 0.07 468.23 40 200 3.33 1.1 0.18 0.41 0.15 0.03 0.73 218 3,446 12,314 86 86 3,360 0.08 468.24 41 205 3.42 1.2 0.20 0.41 0.16 0.03 0.79 238 3,598 12,383 86 86 3,512 0.08 468.25 42 210 3.50 1.3 0.21 0.41 0.18 0.03 0.86 257 3,769 12,462 87 87 3,683 0.08 468.27 43 215 3.58 1.4 0.23 0.41 0.19 0.04 0.92 277 3,960 12,550 87 87 3,873 0.09 468.28 44 220 3.67 1.4 0.23 0.41 0.19 0.04 0.92 277 4,150 12,637 88 88 4,062 0.09 468.29 45 225 3.75 1.5 0.24 0.41 0.21 0.04 0.99 297 4,359 12,733 88 88 4,271 0.10 468.31 46 230 3.83 1.5 0.24 0.41 0.21 0.04 0.99 297 4,568 12,829 89 89 4,479 0.10 468.33 47 235 3.92 1.6 0.26 0.41 0.22 0.04 1.06 317 4,796 12,934 90 90 4,706 0.11 468.34 48 240 4.00 1.6 0.26 0.41 0.22 0.04 1.06 317 5,023 13,038 91 91 4,932 0.11 468.36 49 245 4.08 1.7 0.28 0.41 0.23 0.04 1.12 337 5,269 13,151 91 91 5,177 0.12 468.38 50 250 4.17 1.8 0.29 0.41 0.25 0.05 1.19 356 5,534 13,273 92 92 5,442 0.12 468.40 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 24.97 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.43 Maxwell Drywells UNIT TIME-PERCENT OF LAG 145.8 Number 0 TOTAL ADJUSTED STORM RAIN (in)1.36 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.41 LOW LOSS RATE - PERCENT 83.93% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.31 0.41 0.26 0.05 1.25 376 5,818 13,404 93 93 5,725 0.13 468.42 52 260 4.33 2.0 0.33 0.41 0.27 0.05 1.32 396 6,121 13,543 94 94 6,027 0.14 468.44 53 265 4.42 2.1 0.34 0.41 0.29 0.06 1.39 416 6,443 13,691 95 95 6,347 0.15 468.46 54 270 4.50 2.1 0.34 0.41 0.29 0.06 1.39 416 6,763 13,838 96 96 6,667 0.15 468.48 55 275 4.58 2.2 0.36 0.41 0.30 0.06 1.45 436 7,103 13,994 97 97 7,006 0.16 468.51 56 280 4.67 2.3 0.38 0.41 0.32 0.06 1.52 455 7,461 14,159 98 98 7,363 0.17 468.53 57 285 4.75 2.4 0.39 0.41 0.33 0.06 1.58 475 7,838 14,332 100 100 7,739 0.18 468.56 58 290 4.83 2.4 0.39 0.41 0.33 0.06 1.58 475 8,214 14,505 101 101 8,113 0.19 468.59 59 295 4.92 2.5 0.41 0.41 0.34 0.07 1.65 495 8,608 14,686 102 102 8,506 0.20 468.62 60 300 5.00 2.6 0.42 0.41 0.36 0.02 0.41 122 8,628 14,695 102 102 8,526 0.20 468.62 61 305 5.08 3.1 0.51 0.41 0.42 0.10 2.46 738 9,264 14,987 104 104 9,160 0.21 468.67 62 310 5.17 3.6 0.59 0.41 0.49 0.18 4.51 1,354 10,514 15,562 108 108 10,406 0.24 468.76 63 315 5.25 3.9 0.64 0.41 0.53 0.23 5.75 1,724 12,130 16,305 113 113 12,017 0.28 468.87 64 320 5.33 4.2 0.69 0.41 0.58 0.28 6.98 2,094 14,111 17,175 119 119 13,991 0.32 469.01 65 325 5.42 4.7 0.77 0.41 0.64 0.36 9.03 2,710 16,702 18,058 125 125 16,576 0.38 469.14 66 330 5.50 5.6 0.91 0.41 0.77 0.51 12.73 3,820 20,396 19,316 134 134 20,262 0.47 469.32 67 335 5.58 1.9 0.31 0.41 0.26 0.05 1.25 376 20,638 19,399 135 135 20,503 0.47 469.33 68 340 5.67 0.9 0.15 0.41 0.12 0.02 0.59 178 20,681 19,414 135 135 20,546 0.47 469.33 69 345 5.75 0.6 0.10 0.41 0.08 0.02 0.40 119 20,665 19,408 135 135 20,531 0.47 469.33 70 350 5.83 0.5 0.08 0.41 0.07 0.01 0.33 99 20,630 19,396 135 135 20,495 0.47 469.33 71 355 5.92 0.3 0.05 0.41 0.04 0.01 0.20 59 20,554 19,370 135 135 20,420 0.47 469.33 72 360 6.00 0.2 0.03 0.41 0.03 0.01 0.13 40 20,459 19,338 134 134 20,325 0.47 469.32 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 123,263 cu-ft 1.36 in 96,384 cu-ft 469.33 ft 12.73 cfs 18.20 cf/min 6,554 cu-ft 0.30 in 0.62 acft 26,879 cu-ft 0.47 acft 20,546 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 24.97 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.20 LAG TIME - MINUTES 3.43 C 0.00378 Maxwell Drywells UNIT TIME-PERCENT OF LAG 437%Low Loss Rate (percent)83.93%Number 0 TOTAL ADJUSTED STORM RAIN (in)2.23 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.018 0.721 0.015 0.00 0.07 65 65 10,760 224 65 0 0.00 468.00 2 30 0.50 0.3 0.027 0.712 0.022 0.00 0.11 97 97 10,775 224 97 0 0.00 468.00 3 45 0.75 0.3 0.027 0.704 0.022 0.00 0.11 97 97 10,775 224 97 0 0.00 468.00 4 60 1.00 0.4 0.036 0.696 0.030 0.01 0.14 130 130 10,790 225 130 0 0.00 468.00 5 75 1.25 0.3 0.027 0.688 0.022 0.00 0.11 97 97 10,775 224 97 0 0.00 468.00 6 90 1.50 0.3 0.027 0.680 0.022 0.00 0.11 97 97 10,775 224 97 0 0.00 468.00 7 105 1.75 0.3 0.027 0.671 0.022 0.00 0.11 97 97 10,775 224 97 0 0.00 468.00 8 120 2.00 0.4 0.036 0.663 0.030 0.01 0.14 130 130 10,790 225 130 0 0.00 468.00 9 135 2.25 0.4 0.036 0.655 0.030 0.01 0.14 130 130 10,790 225 130 0 0.00 468.00 10 150 2.50 0.4 0.036 0.647 0.030 0.01 0.14 130 130 10,790 225 130 0 0.00 468.00 11 165 2.75 0.5 0.045 0.639 0.037 0.01 0.18 162 162 10,805 225 162 0 0.00 468.00 12 180 3.00 0.5 0.045 0.632 0.037 0.01 0.18 162 162 10,805 225 162 0 0.00 468.00 13 195 3.25 0.5 0.045 0.624 0.037 0.01 0.18 162 162 10,805 225 162 0 0.00 468.00 14 210 3.50 0.5 0.045 0.616 0.037 0.01 0.18 162 162 10,805 225 162 0 0.00 468.00 15 225 3.75 0.5 0.045 0.608 0.037 0.01 0.18 162 162 10,805 225 162 0 0.00 468.00 16 240 4.00 0.6 0.054 0.601 0.045 0.01 0.22 195 195 10,820 225 195 0 0.00 468.00 17 255 4.25 0.6 0.054 0.593 0.045 0.01 0.22 195 195 10,820 225 195 0 0.00 468.00 18 270 4.50 0.7 0.062 0.585 0.052 0.01 0.25 227 227 10,834 226 226 2 0.00 468.00 19 285 4.75 0.7 0.062 0.578 0.052 0.01 0.25 227 229 10,835 226 226 3 0.00 468.00 20 300 5.00 0.8 0.071 0.570 0.060 0.01 0.29 260 263 10,851 226 226 37 0.00 468.00 21 315 5.25 0.6 0.054 0.563 0.045 0.01 0.22 195 232 10,836 226 226 6 0.00 468.00 22 330 5.50 0.7 0.062 0.556 0.052 0.01 0.25 227 233 10,837 226 226 7 0.00 468.00 23 345 5.75 0.8 0.071 0.548 0.060 0.01 0.29 260 267 10,853 226 226 41 0.00 468.00 24 360 6.00 0.8 0.071 0.541 0.060 0.01 0.29 260 301 10,868 226 226 74 0.00 468.01 25 375 6.25 0.9 0.080 0.534 0.067 0.01 0.32 292 367 10,898 227 227 140 0.00 468.01 26 390 6.50 0.9 0.080 0.527 0.067 0.01 0.32 292 432 10,928 228 228 204 0.00 468.01 27 405 6.75 1.0 0.089 0.520 0.075 0.01 0.36 325 529 10,973 229 229 300 0.01 468.02 28 420 7.00 1.0 0.089 0.513 0.075 0.01 0.36 325 625 11,017 230 230 395 0.01 468.03 29 435 7.25 1.0 0.089 0.506 0.075 0.01 0.36 325 720 11,061 230 230 490 0.01 468.04 30 450 7.50 1.1 0.098 0.499 0.082 0.02 0.40 357 847 11,119 232 232 615 0.01 468.04 31 465 7.75 1.2 0.107 0.492 0.090 0.02 0.43 390 1,005 11,192 233 233 772 0.02 468.06 32 480 8.00 1.3 0.116 0.485 0.097 0.02 0.47 422 1,194 11,279 235 235 959 0.02 468.07 33 495 8.25 1.5 0.134 0.479 0.112 0.02 0.54 487 1,446 11,394 237 237 1,208 0.03 468.09 34 510 8.50 1.5 0.134 0.472 0.112 0.02 0.54 487 1,695 11,509 240 240 1,456 0.03 468.11 35 525 8.75 1.6 0.143 0.465 0.120 0.02 0.58 520 1,975 11,638 242 242 1,733 0.04 468.13 36 540 9.00 1.7 0.152 0.459 0.127 0.02 0.61 552 2,285 11,780 245 245 2,039 0.05 468.15 37 555 9.25 1.9 0.169 0.452 0.142 0.03 0.69 617 2,656 11,951 249 249 2,407 0.06 468.17 38 570 9.50 2.0 0.178 0.446 0.150 0.03 0.72 649 3,057 12,135 253 253 2,804 0.06 468.20 39 585 9.75 2.1 0.187 0.439 0.157 0.03 0.76 682 3,486 12,332 257 257 3,229 0.07 468.23 40 600 10.00 2.2 0.196 0.433 0.165 0.03 0.79 714 3,943 12,542 261 261 3,682 0.08 468.27 41 615 10.25 1.5 0.134 0.427 0.112 0.02 0.54 487 4,169 12,646 263 263 3,905 0.09 468.28 42 630 10.50 1.5 0.134 0.421 0.112 0.02 0.54 487 4,392 12,749 266 266 4,127 0.09 468.30 43 645 10.75 2.0 0.178 0.415 0.150 0.03 0.72 649 4,776 12,925 269 269 4,507 0.10 468.33 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 24.97 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.20 LAG TIME - MINUTES 3.43 C 0.00378 Maxwell Drywells UNIT TIME-PERCENT OF LAG 437%Low Loss Rate (percent)83.93%Number 0 TOTAL ADJUSTED STORM RAIN (in)2.23 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 44 660 11.00 2.0 0.178 0.409 0.150 0.03 0.72 649 5,156 13,100 273 273 4,883 0.11 468.35 45 675 11.25 1.9 0.169 0.403 0.142 0.03 0.69 617 5,500 13,258 276 276 5,224 0.12 468.38 46 690 11.50 1.9 0.169 0.397 0.142 0.03 0.69 617 5,841 13,415 279 279 5,562 0.13 468.40 47 705 11.75 1.7 0.152 0.391 0.127 0.02 0.61 552 6,114 13,540 282 282 5,832 0.13 468.42 48 720 12.00 1.8 0.161 0.385 0.135 0.03 0.65 584 6,416 13,679 285 285 6,131 0.14 468.45 49 735 12.25 2.5 0.223 0.379 0.187 0.04 0.90 812 6,943 13,921 290 290 6,653 0.15 468.48 50 750 12.50 2.6 0.232 0.373 0.195 0.04 0.94 844 7,497 14,176 295 295 7,202 0.17 468.52 51 765 12.75 2.8 0.250 0.368 0.210 0.04 1.01 909 8,111 14,458 301 301 7,810 0.18 468.57 52 780 13.00 2.9 0.259 0.362 0.217 0.04 1.05 942 8,751 14,752 307 307 8,444 0.19 468.61 53 795 13.25 3.4 0.303 0.357 0.255 0.05 1.23 1,104 9,548 15,118 315 315 9,233 0.21 468.67 54 810 13.50 3.4 0.303 0.351 0.255 0.05 1.23 1,104 10,337 15,481 323 323 10,014 0.23 468.73 55 825 13.75 2.3 0.205 0.346 0.172 0.03 0.83 747 10,761 15,676 327 327 10,435 0.24 468.76 56 840 14.00 2.3 0.205 0.341 0.172 0.03 0.83 747 11,181 15,869 331 331 10,851 0.25 468.79 57 855 14.25 2.7 0.241 0.336 0.202 0.04 0.97 877 11,728 16,120 336 336 11,392 0.26 468.83 58 870 14.50 2.6 0.232 0.331 0.195 0.04 0.94 844 12,236 16,353 341 341 11,895 0.27 468.86 59 885 14.75 2.6 0.232 0.325 0.195 0.04 0.94 844 12,739 16,585 346 346 12,394 0.28 468.90 60 900 15.00 2.5 0.223 0.320 0.187 0.04 0.90 812 13,206 16,799 350 350 12,856 0.30 468.93 61 915 15.25 2.4 0.214 0.316 0.180 0.03 0.87 779 13,635 16,996 354 354 13,281 0.30 468.96 62 930 15.50 2.3 0.205 0.311 0.172 0.03 0.83 747 14,028 17,147 357 357 13,670 0.31 468.99 63 945 15.75 1.9 0.169 0.306 0.142 0.03 0.69 617 14,287 17,235 359 359 13,928 0.32 469.01 64 960 16.00 1.9 0.169 0.301 0.142 0.03 0.69 617 14,545 17,323 361 361 14,184 0.33 469.02 65 975 16.25 0.4 0.036 0.297 0.030 0.01 0.14 130 14,314 17,244 359 359 13,955 0.32 469.01 66 990 16.50 0.4 0.036 0.292 0.030 0.01 0.14 130 14,085 17,166 358 358 13,727 0.32 469.00 67 1005 16.75 0.3 0.027 0.288 0.022 0.00 0.11 97 13,825 17,077 356 356 13,469 0.31 468.98 68 1020 17.00 0.3 0.027 0.283 0.022 0.00 0.11 97 13,566 16,965 353 353 13,213 0.30 468.96 69 1035 17.25 0.5 0.045 0.279 0.037 0.01 0.18 162 13,375 16,877 352 352 13,024 0.30 468.95 70 1050 17.50 0.5 0.045 0.275 0.037 0.01 0.18 162 13,186 16,790 350 350 12,836 0.29 468.93 71 1065 17.75 0.5 0.045 0.271 0.037 0.01 0.18 162 12,998 16,704 348 348 12,650 0.29 468.92 72 1080 18.00 0.4 0.036 0.267 0.030 0.01 0.14 130 12,780 16,604 346 346 12,434 0.29 468.90 73 1095 18.25 0.4 0.036 0.263 0.030 0.01 0.14 130 12,564 16,504 344 344 12,220 0.28 468.89 74 1110 18.50 0.4 0.036 0.259 0.030 0.01 0.14 130 12,350 16,406 342 342 12,009 0.28 468.87 75 1125 18.75 0.3 0.027 0.255 0.022 0.00 0.11 97 12,106 16,294 339 339 11,766 0.27 468.85 76 1140 19.00 0.2 0.018 0.252 0.015 0.00 0.07 65 11,831 16,168 337 337 11,495 0.26 468.83 77 1155 19.25 0.3 0.027 0.248 0.022 0.00 0.11 97 11,592 16,058 335 335 11,257 0.26 468.82 78 1170 19.50 0.4 0.036 0.245 0.030 0.01 0.14 130 11,387 15,963 333 333 11,055 0.25 468.80 79 1185 19.75 0.3 0.027 0.241 0.022 0.00 0.11 97 11,152 15,855 330 330 10,822 0.25 468.79 80 1200 20.00 0.2 0.018 0.238 0.015 0.00 0.07 65 10,887 15,733 328 328 10,559 0.24 468.77 81 1215 20.25 0.3 0.027 0.235 0.022 0.00 0.11 97 10,656 15,628 326 326 10,331 0.24 468.75 82 1230 20.50 0.3 0.027 0.232 0.022 0.00 0.11 97 10,428 15,523 323 323 10,105 0.23 468.73 83 1245 20.75 0.3 0.027 0.229 0.022 0.00 0.11 97 10,202 15,419 321 321 9,881 0.23 468.72 84 1260 21.00 0.2 0.018 0.226 0.015 0.00 0.07 65 9,946 15,301 319 319 9,627 0.22 468.70 85 1275 21.25 0.3 0.027 0.224 0.022 0.00 0.11 97 9,725 15,199 317 317 9,408 0.22 468.68 86 1290 21.50 0.2 0.018 0.221 0.015 0.00 0.07 65 9,473 15,084 314 314 9,159 0.21 468.66 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 3/30/20 DRAINAGE AREA-ACRES 24.97 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.20 LAG TIME - MINUTES 3.43 C 0.00378 Maxwell Drywells UNIT TIME-PERCENT OF LAG 437%Low Loss Rate (percent)83.93%Number 0 TOTAL ADJUSTED STORM RAIN (in)2.23 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 87 1305 21.75 0.3 0.027 0.219 0.022 0.00 0.11 97 9,256 14,984 312 312 8,944 0.21 468.65 88 1320 22.00 0.2 0.018 0.216 0.015 0.00 0.07 65 9,009 14,870 310 310 8,699 0.20 468.63 89 1335 22.25 0.3 0.027 0.214 0.022 0.00 0.11 97 8,796 14,773 308 308 8,489 0.19 468.62 90 1350 22.50 0.2 0.018 0.212 0.015 0.00 0.07 65 8,554 14,661 305 305 8,248 0.19 468.60 91 1365 22.75 0.2 0.018 0.210 0.015 0.00 0.07 65 8,313 14,551 303 303 8,010 0.18 468.58 92 1380 23.00 0.2 0.018 0.209 0.015 0.00 0.07 65 8,075 14,441 301 301 7,774 0.18 468.56 93 1395 23.25 0.2 0.018 0.207 0.015 0.00 0.07 65 7,839 14,333 299 299 7,540 0.17 468.55 94 1410 23.50 0.2 0.018 0.206 0.015 0.00 0.07 65 7,605 14,225 296 296 7,309 0.17 468.53 95 1425 23.75 0.2 0.018 0.205 0.015 0.00 0.07 65 7,374 14,119 294 294 7,080 0.16 468.51 96 1440 24.00 0.2 0.018 0.204 0.015 0.00 0.07 65 7,145 14,014 292 292 6,853 0.16 468.50 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 2.23 in 202,114 cu-ft 169,645 cu-ft 469.02 ft 1.23 cfs 25,617 cu-ft 17.79 cf/min 0.36 in 0.75 acft 32,470 cu-ft 0.33 acft 14,184 cu-ft Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 468 0 0 10,730 0 0 0.00 469 1 1 6,330 17,060 13,773 13,773 0.32 470 1 2 6,965 24,025 20,443 34,217 0.79 WHERE: TOTAL 10 YEAR BASIN BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 11 D EXISTING BARREN 35.652 X 93 0.09 0.05 12 B EXISTING OPEN BRUSH - POOR 35.233 X 76 0.29 0.05 2 B PAVING/HARDSCAPE 2.082 D 56 0.51 1.00 3 B WATER FEATURE 18.699 D 56 0.51 1.00 1 B COMMERCIAL 5.752 D 56 0.51 0.90 6 B SF - HIGH DENSITY 8.141 D 56 0.51 0.50 9 B LANDSCAPING 57.186 D 56 0.51 0.10 1,180 ft 590 ft 960.0 ft ELEVATION OF CONCENTRATION POINT 456.0 ft 0.03 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 451.0 ft 707,505 sf 455.0 ft 810,350 sf PERCOLATION RATE (in/hr)0.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 WAVE LAGOON AMC NUMBER RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-A Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)850,704 1,264,241 1,630,516 2,605,281 SOIL LOSSES (cu-ft)157,045 464,495 840,545 1,801,551 EFFECTIVE RAIN (in)1.17 1.35 1.34 1.36 FLOOD VOLUME (cu-ft)693,659 799,746 789,971 803,730 (acre-ft)15.92 18.36 18.14 18.45 REQUIRED STORAGE (cu-ft)693,659 799,746 789,971 803,730 (acre-ft)15.92 18.36 18.14 18.45 FACTOR OF SAFETY 4.37 3.79 3.84 3.77 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 301.94 260.74 60.87 MAXIMUM WSEL (ft)451.91 452.05 452.04 452.06 DEPTH (ft)0.91 1.05 1.04 1.06 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days) WAVE LAGOON DA-A CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 162.745 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION [3] AREA - ACRES [4] L-FEET [5] L-MILES 1180 0.223 [13] L*LCA/S^0.5 47.49 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.001 590.00 [12] S^0.5 0.112 2255.2 960 456 504 0.03 [17] 100% OF LAG-MINUTES 2.5 2.5 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.04 [16] LAG TIME-MINUTES [18] 200% OF LAG-MINUTES RAINFALL DATA 4.9 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 3,033,385 69.64 Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] D 93 0.09 5%0.09 35.652 0.219 0.0188 UNDEVELOPED 0.9000 0.1972 B 76 0.29 5%0.28 35.233 0.216 0.0600 UNDEVELOPED 0.9000 0.1948 B 56 0.51 100%0.05 2.082 0.013 0.0007 DEVELOPED 0.1000 0.0013 B 56 0.51 100%0.05 18.699 0.115 0.0059 DEVELOPED 0.1000 0.0115 B 56 0.51 90%0.10 5.752 0.035 0.0034 DEVELOPED 0.1800 0.0064 B 56 0.51 50%0.28 8.141 0.050 0.0140 DEVELOPED 0.5000 0.0250 B 56 0.51 10%0.46 57.186 0.351 0.1631 DEVELOPED 0.8200 0.2881 SUM 162.745 SUM 0.2658 0.7243 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.132916039 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00246 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00246 0.13 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.2658 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II (24-(T/60))^1.55 + LAND USE EXISTING BARREN EXISTING OPEN BRUSH - POOR PAVING/HARDSCAPE WATER FEATURE COMMERCIAL SF - HIGH DENSITY LANDSCAPING Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 162.75 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.45 Maxwell Drywells UNIT TIME-PERCENT OF LAG 204.0 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.27 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.27 0.53 0.36 58.46 17,538 17,538 708,100 0 0 17,538 0.40 451.02 2 10 0.17 4.2 0.73 0.27 0.62 0.46 75.48 22,643 40,181 708,867 0 0 40,181 0.92 451.05 3 15 0.25 4.4 0.76 0.27 0.65 0.49 81.15 24,344 64,525 709,693 0 0 64,525 1.48 451.09 4 20 0.33 4.6 0.79 0.27 0.68 0.53 86.82 26,045 90,570 710,576 0 0 90,570 2.08 451.12 5 25 0.42 5.0 0.86 0.27 0.73 0.60 98.16 29,448 120,018 711,574 0 0 120,018 2.76 451.16 6 30 0.50 5.6 0.97 0.27 0.82 0.70 115.17 34,552 154,571 712,746 0 0 154,571 3.55 451.20 7 35 0.58 6.4 1.11 0.27 0.94 0.84 137.86 41,358 195,929 714,148 0 0 195,929 4.50 451.26 8 40 0.67 8.1 1.40 0.27 1.19 1.13 186.07 55,820 251,748 716,040 0 0 251,748 5.78 451.33 9 45 0.75 13.1 2.26 0.27 1.92 2.00 327.85 98,355 350,104 719,375 0 0 350,104 8.04 451.46 10 50 0.83 34.5 5.96 0.27 5.07 5.70 934.69 280,406 630,509 728,882 0 0 630,509 14.47 451.83 11 55 0.92 6.7 1.16 0.27 0.98 0.89 146.37 43,910 674,420 730,371 0 0 674,420 15.48 451.89 12 60 1.00 3.8 0.66 0.27 0.56 0.39 64.13 19,240 693,659 731,023 0 0 693,659 15.92 451.91 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 850,704 cu-ft SOIL LOSSES 157,045 cu-ft EFFECTIVE RAIN 1.17 in FLOOD VOLUME 15.92 acft FLOOD VOLUME 693,659 cu-ft REQUIRED STORAGE 15.92 REQUIRED STORAGE 693,659 cu-ft MAX WSEL 451.91 ft PEAK FLOW RATE 934.69 cfs TOTAL BASIN LOSSES 0 cu-ft AVERAGE PERCOLATION RATE 0.00 cf/min CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 162.75 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.45 Maxwell Drywells UNIT TIME-PERCENT OF LAG 204.0 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.27 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.27 0.28 0.07 11.16 3,348 3,348 707,619 0 0 3,348 0.08 451.00 2 10 0.17 1.3 0.33 0.27 0.28 0.07 11.16 3,348 6,696 707,732 0 0 6,696 0.15 451.01 3 15 0.25 1.1 0.28 0.27 0.24 0.02 2.73 820 7,516 707,760 0 0 7,516 0.17 451.01 4 20 0.33 1.5 0.39 0.27 0.33 0.12 19.59 5,877 13,392 707,959 0 0 13,392 0.31 451.02 5 25 0.42 1.5 0.39 0.27 0.33 0.12 19.59 5,877 19,269 708,158 0 0 19,269 0.44 451.03 6 30 0.50 1.8 0.46 0.27 0.39 0.20 32.23 9,669 28,938 708,486 0 0 28,938 0.66 451.04 7 35 0.58 1.5 0.39 0.27 0.33 0.12 19.59 5,877 34,815 708,685 0 0 34,815 0.80 451.05 8 40 0.67 1.8 0.46 0.27 0.39 0.20 32.23 9,669 44,484 709,013 0 0 44,484 1.02 451.06 9 45 0.75 1.8 0.46 0.27 0.39 0.20 32.23 9,669 54,153 709,341 0 0 54,153 1.24 451.07 10 50 0.83 1.5 0.39 0.27 0.33 0.12 19.59 5,877 60,030 709,540 0 0 60,030 1.38 451.08 11 55 0.92 1.6 0.41 0.27 0.35 0.15 23.80 7,141 67,171 709,782 0 0 67,171 1.54 451.09 12 60 1.00 1.8 0.46 0.27 0.39 0.20 32.23 9,669 76,840 710,110 0 0 76,840 1.76 451.10 13 65 1.08 2.2 0.56 0.27 0.48 0.30 49.09 14,726 91,566 710,609 0 0 91,566 2.10 451.12 14 70 1.17 2.2 0.56 0.27 0.48 0.30 49.09 14,726 106,292 711,109 0 0 106,292 2.44 451.14 15 75 1.25 2.2 0.56 0.27 0.48 0.30 49.09 14,726 121,018 711,608 0 0 121,018 2.78 451.16 16 80 1.33 2.0 0.51 0.27 0.44 0.25 40.66 12,198 133,216 712,022 0 0 133,216 3.06 451.18 17 85 1.42 2.6 0.67 0.27 0.57 0.40 65.94 19,783 152,999 712,692 0 0 152,999 3.51 451.20 18 90 1.50 2.7 0.69 0.27 0.59 0.43 70.16 21,047 174,047 713,406 0 0 174,047 4.00 451.23 19 95 1.58 2.4 0.62 0.27 0.52 0.35 57.52 17,255 191,302 713,991 0 0 191,302 4.39 451.25 20 100 1.67 2.7 0.69 0.27 0.59 0.43 70.16 21,047 212,349 714,705 0 0 212,349 4.87 451.28 21 105 1.75 3.3 0.85 0.27 0.72 0.58 95.44 28,633 240,982 715,675 0 0 240,982 5.53 451.32 22 110 1.83 3.1 0.80 0.27 0.68 0.53 87.01 26,104 267,086 716,560 0 0 267,086 6.13 451.35 23 115 1.92 2.9 0.74 0.27 0.63 0.48 78.59 23,576 290,662 717,360 0 0 290,662 6.67 451.38 24 120 2.00 3.0 0.77 0.27 0.65 0.50 82.80 24,840 315,502 718,202 0 0 315,502 7.24 451.42 25 125 2.08 3.1 0.80 0.27 0.68 0.53 87.01 26,104 341,607 719,087 0 0 341,607 7.84 451.45 Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 162.75 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.45 Maxwell Drywells UNIT TIME-PERCENT OF LAG 204.0 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.27 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD 26 130 2.17 4.2 1.08 0.27 0.92 0.81 133.37 40,011 381,618 720,444 0 0 381,618 8.76 451.50 27 135 2.25 5.0 1.28 0.27 1.09 1.02 167.08 50,125 431,743 722,143 0 0 431,743 9.91 451.57 28 140 2.33 3.5 0.90 0.27 0.76 0.63 103.87 31,161 462,904 723,199 0 0 462,904 10.63 451.61 29 145 2.42 6.8 1.75 0.27 1.48 1.48 242.94 72,881 535,785 725,670 0 0 535,785 12.30 451.71 30 150 2.50 7.3 1.87 0.27 1.59 1.61 264.01 79,203 614,988 728,356 0 0 614,988 14.12 451.81 31 155 2.58 8.2 2.11 0.27 1.79 1.84 301.94 90,581 705,569 731,427 0 0 705,569 16.20 451.93 32 160 2.67 5.9 1.52 0.27 1.29 1.25 205.01 61,503 767,072 733,512 0 0 767,072 17.61 452.01 33 165 2.75 2.0 0.51 0.27 0.44 0.25 40.66 12,198 779,270 733,926 0 0 779,270 17.89 452.03 34 170 2.83 1.8 0.46 0.27 0.39 0.20 32.23 9,669 788,939 734,253 0 0 788,939 18.11 452.04 35 175 2.92 1.8 0.46 0.27 0.39 0.20 32.23 9,669 798,608 734,581 0 0 798,608 18.33 452.05 36 180 3.00 0.6 0.15 0.27 0.13 0.02 3.79 1,138 799,746 734,620 0 0 799,746 18.36 452.05 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 464,495 cu-ft 2.14 in 1,264,241 cu-ft 452.05 ft 301.94 cfs 0 cu-ft 0.00 cf/min 1.35 in 18.36 acft 799,746 cu-ft 18.36 acft 799,746 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 162.75 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.45 Maxwell Drywells UNIT TIME-PERCENT OF LAG 204.0 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.27 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.27 0.14 0.02 4.08 1,223 1,223 707,546 0 0 1,223 0.03 451.00 2 10 0.17 0.6 0.20 0.27 0.17 0.03 4.89 1,467 2,690 707,596 0 0 2,690 0.06 451.00 3 15 0.25 0.6 0.20 0.27 0.17 0.03 4.89 1,467 4,158 707,646 0 0 4,158 0.10 451.01 4 20 0.33 0.6 0.20 0.27 0.17 0.03 4.89 1,467 5,625 707,696 0 0 5,625 0.13 451.01 5 25 0.42 0.6 0.20 0.27 0.17 0.03 4.89 1,467 7,093 707,745 0 0 7,093 0.16 451.01 6 30 0.50 0.7 0.23 0.27 0.20 0.03 5.71 1,712 8,805 707,804 0 0 8,805 0.20 451.01 7 35 0.58 0.7 0.23 0.27 0.20 0.03 5.71 1,712 10,517 707,862 0 0 10,517 0.24 451.01 8 40 0.67 0.7 0.23 0.27 0.20 0.03 5.71 1,712 12,229 707,920 0 0 12,229 0.28 451.02 9 45 0.75 0.7 0.23 0.27 0.20 0.03 5.71 1,712 13,941 707,978 0 0 13,941 0.32 451.02 10 50 0.83 0.7 0.23 0.27 0.20 0.03 5.71 1,712 15,653 708,036 0 0 15,653 0.36 451.02 11 55 0.92 0.7 0.23 0.27 0.20 0.03 5.71 1,712 17,365 708,094 0 0 17,365 0.40 451.02 12 60 1.00 0.8 0.26 0.27 0.23 0.04 6.52 1,957 19,322 708,160 0 0 19,322 0.44 451.03 13 65 1.08 0.8 0.26 0.27 0.23 0.04 6.52 1,957 21,278 708,226 0 0 21,278 0.49 451.03 14 70 1.17 0.8 0.26 0.27 0.23 0.04 6.52 1,957 23,235 708,293 0 0 23,235 0.53 451.03 15 75 1.25 0.8 0.26 0.27 0.23 0.04 6.52 1,957 25,191 708,359 0 0 25,191 0.58 451.03 16 80 1.33 0.8 0.26 0.27 0.23 0.04 6.52 1,957 27,148 708,425 0 0 27,148 0.62 451.04 17 85 1.42 0.8 0.26 0.27 0.23 0.04 6.52 1,957 29,105 708,492 0 0 29,105 0.67 451.04 18 90 1.50 0.8 0.26 0.27 0.23 0.04 6.52 1,957 31,061 708,558 0 0 31,061 0.71 451.04 19 95 1.58 0.8 0.26 0.27 0.23 0.04 6.52 1,957 33,018 708,624 0 0 33,018 0.76 451.04 20 100 1.67 0.8 0.26 0.27 0.23 0.04 6.52 1,957 34,975 708,691 0 0 34,975 0.80 451.05 21 105 1.75 0.8 0.26 0.27 0.23 0.04 6.52 1,957 36,931 708,757 0 0 36,931 0.85 451.05 22 110 1.83 0.8 0.26 0.27 0.23 0.04 6.52 1,957 38,888 708,823 0 0 38,888 0.89 451.05 23 115 1.92 0.8 0.26 0.27 0.23 0.04 6.52 1,957 40,844 708,890 0 0 40,844 0.94 451.05 24 120 2.00 0.9 0.30 0.27 0.25 0.03 5.29 1,588 42,432 708,944 0 0 42,432 0.97 451.06 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 162.75 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.45 Maxwell Drywells UNIT TIME-PERCENT OF LAG 204.0 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.27 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.27 0.23 0.04 6.52 1,957 44,389 709,010 0 0 44,389 1.02 451.06 26 130 2.17 0.9 0.30 0.27 0.25 0.03 5.29 1,588 45,976 709,064 0 0 45,976 1.06 451.06 27 135 2.25 0.9 0.30 0.27 0.25 0.03 5.29 1,588 47,564 709,118 0 0 47,564 1.09 451.06 28 140 2.33 0.9 0.30 0.27 0.25 0.03 5.29 1,588 49,151 709,171 0 0 49,151 1.13 451.06 29 145 2.42 0.9 0.30 0.27 0.25 0.03 5.29 1,588 50,739 709,225 0 0 50,739 1.16 451.07 30 150 2.50 0.9 0.30 0.27 0.25 0.03 5.29 1,588 52,327 709,279 0 0 52,327 1.20 451.07 31 155 2.58 0.9 0.30 0.27 0.25 0.03 5.29 1,588 53,914 709,333 0 0 53,914 1.24 451.07 32 160 2.67 0.9 0.30 0.27 0.25 0.03 5.29 1,588 55,502 709,387 0 0 55,502 1.27 451.07 33 165 2.75 1.0 0.33 0.27 0.28 0.07 10.73 3,218 58,720 709,496 0 0 58,720 1.35 451.08 34 170 2.83 1.0 0.33 0.27 0.28 0.07 10.73 3,218 61,938 709,605 0 0 61,938 1.42 451.08 35 175 2.92 1.0 0.33 0.27 0.28 0.07 10.73 3,218 65,156 709,714 0 0 65,156 1.50 451.09 36 180 3.00 1.0 0.33 0.27 0.28 0.07 10.73 3,218 68,374 709,823 0 0 68,374 1.57 451.09 37 185 3.08 1.0 0.33 0.27 0.28 0.07 10.73 3,218 71,592 709,932 0 0 71,592 1.64 451.09 38 190 3.17 1.1 0.36 0.27 0.31 0.10 16.16 4,849 76,441 710,097 0 0 76,441 1.75 451.10 39 195 3.25 1.1 0.36 0.27 0.31 0.10 16.16 4,849 81,289 710,261 0 0 81,289 1.87 451.11 40 200 3.33 1.1 0.36 0.27 0.31 0.10 16.16 4,849 86,138 710,425 0 0 86,138 1.98 451.11 41 205 3.42 1.2 0.40 0.27 0.34 0.13 21.60 6,479 92,617 710,645 0 0 92,617 2.13 451.12 42 210 3.50 1.3 0.43 0.27 0.37 0.16 27.03 8,110 100,727 710,920 0 0 100,727 2.31 451.13 43 215 3.58 1.4 0.46 0.27 0.39 0.20 32.47 9,740 110,467 711,250 0 0 110,467 2.54 451.15 44 220 3.67 1.4 0.46 0.27 0.39 0.20 32.47 9,740 120,207 711,581 0 0 120,207 2.76 451.16 45 225 3.75 1.5 0.50 0.27 0.42 0.23 37.90 11,371 131,578 711,966 0 0 131,578 3.02 451.17 46 230 3.83 1.5 0.50 0.27 0.42 0.23 37.90 11,371 142,949 712,352 0 0 142,949 3.28 451.19 47 235 3.92 1.6 0.53 0.27 0.45 0.26 43.34 13,001 155,950 712,792 0 0 155,950 3.58 451.21 48 240 4.00 1.6 0.53 0.27 0.45 0.26 43.34 13,001 168,951 713,233 0 0 168,951 3.88 451.22 49 245 4.08 1.7 0.56 0.27 0.48 0.30 48.77 14,632 183,583 713,729 0 0 183,583 4.21 451.24 50 250 4.17 1.8 0.60 0.27 0.51 0.33 54.21 16,262 199,845 714,281 0 0 199,845 4.59 451.26 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 162.75 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.45 Maxwell Drywells UNIT TIME-PERCENT OF LAG 204.0 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.27 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.27 0.53 0.36 59.64 17,893 217,738 714,887 0 0 217,738 5.00 451.29 52 260 4.33 2.0 0.66 0.27 0.56 0.40 65.08 19,523 237,261 715,549 0 0 237,261 5.45 451.31 53 265 4.42 2.1 0.70 0.27 0.59 0.43 70.51 21,154 258,415 716,266 0 0 258,415 5.93 451.34 54 270 4.50 2.1 0.70 0.27 0.59 0.43 70.51 21,154 279,568 716,984 0 0 279,568 6.42 451.37 55 275 4.58 2.2 0.73 0.27 0.62 0.46 75.95 22,784 302,353 717,756 0 0 302,353 6.94 451.40 56 280 4.67 2.3 0.76 0.27 0.65 0.50 81.38 24,415 326,767 718,584 0 0 326,767 7.50 451.43 57 285 4.75 2.4 0.79 0.27 0.68 0.53 86.82 26,045 352,813 719,467 0 0 352,813 8.10 451.47 58 290 4.83 2.4 0.79 0.27 0.68 0.53 86.82 26,045 378,858 720,350 0 0 378,858 8.70 451.50 59 295 4.92 2.5 0.83 0.27 0.70 0.56 92.25 27,676 406,534 721,288 0 0 406,534 9.33 451.54 60 300 5.00 2.6 0.86 0.27 0.73 0.60 97.69 29,306 435,840 722,282 0 0 435,840 10.01 451.57 61 305 5.08 3.1 1.03 0.27 0.87 0.76 124.86 37,459 473,299 723,552 0 0 473,299 10.87 451.62 62 310 5.17 3.6 1.19 0.27 1.01 0.93 152.04 45,612 518,911 725,098 0 0 518,911 11.91 451.68 63 315 5.25 3.9 1.29 0.27 1.10 1.03 168.34 50,503 569,414 726,811 0 0 569,414 13.07 451.75 64 320 5.33 4.2 1.39 0.27 1.18 1.13 184.65 55,395 624,808 728,689 0 0 624,808 14.34 451.82 65 325 5.42 4.7 1.56 0.27 1.32 1.29 211.82 63,547 688,356 730,843 0 0 688,356 15.80 451.91 66 330 5.50 5.6 1.85 0.27 1.58 1.59 260.74 78,222 766,577 733,495 0 0 766,577 17.60 452.01 67 335 5.58 1.9 0.63 0.27 0.53 0.36 59.64 17,893 784,470 734,102 0 0 784,470 18.01 452.03 68 340 5.67 0.9 0.30 0.27 0.25 0.03 5.29 1,588 786,058 734,156 0 0 786,058 18.05 452.04 69 345 5.75 0.6 0.20 0.27 0.17 0.03 4.89 1,467 787,525 734,206 0 0 787,525 18.08 452.04 70 350 5.83 0.5 0.17 0.27 0.14 0.02 4.08 1,223 788,748 734,247 0 0 788,748 18.11 452.04 71 355 5.92 0.3 0.10 0.27 0.08 0.01 2.45 734 789,482 734,272 0 0 789,482 18.12 452.04 72 360 6.00 0.2 0.07 0.27 0.06 0.01 1.63 489 789,971 734,288 0 0 789,971 18.14 452.04 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 1,630,516 cu-ft 2.76 in 840,545 cu-ft 452.04 ft 260.74 cfs 0.00 cf/min 0 cu-ft 1.34 in 18.14 acft 789,971 cu-ft 18.14 acft 789,971 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 162.75 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.13 LAG TIME - MINUTES 2.45 C 0.00246 Maxwell Drywells UNIT TIME-PERCENT OF LAG 612%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.469 0.030 0.01 0.87 782 782 707,531 0 0 782 0.02 451.00 2 30 0.50 0.3 0.053 0.464 0.045 0.01 1.30 1,172 1,954 707,571 0 0 1,954 0.04 451.00 3 45 0.75 0.3 0.053 0.459 0.045 0.01 1.30 1,172 3,126 707,611 0 0 3,126 0.07 451.00 4 60 1.00 0.4 0.071 0.453 0.060 0.01 1.74 1,563 4,690 707,664 0 0 4,690 0.11 451.01 5 75 1.25 0.3 0.053 0.448 0.045 0.01 1.30 1,172 5,862 707,704 0 0 5,862 0.13 451.01 6 90 1.50 0.3 0.053 0.443 0.045 0.01 1.30 1,172 7,034 707,743 0 0 7,034 0.16 451.01 7 105 1.75 0.3 0.053 0.437 0.045 0.01 1.30 1,172 8,207 707,783 0 0 8,207 0.19 451.01 8 120 2.00 0.4 0.071 0.432 0.060 0.01 1.74 1,563 9,770 707,836 0 0 9,770 0.22 451.01 9 135 2.25 0.4 0.071 0.427 0.060 0.01 1.74 1,563 11,333 707,889 0 0 11,333 0.26 451.01 10 150 2.50 0.4 0.071 0.422 0.060 0.01 1.74 1,563 12,896 707,942 0 0 12,896 0.30 451.02 11 165 2.75 0.5 0.088 0.416 0.075 0.01 2.17 1,954 14,850 708,008 0 0 14,850 0.34 451.02 12 180 3.00 0.5 0.088 0.411 0.075 0.01 2.17 1,954 16,804 708,075 0 0 16,804 0.39 451.02 13 195 3.25 0.5 0.088 0.406 0.075 0.01 2.17 1,954 18,758 708,141 0 0 18,758 0.43 451.02 14 210 3.50 0.5 0.088 0.401 0.075 0.01 2.17 1,954 20,712 708,207 0 0 20,712 0.48 451.03 15 225 3.75 0.5 0.088 0.396 0.075 0.01 2.17 1,954 22,666 708,273 0 0 22,666 0.52 451.03 16 240 4.00 0.6 0.106 0.391 0.090 0.02 2.61 2,345 25,011 708,353 0 0 25,011 0.57 451.03 17 255 4.25 0.6 0.106 0.386 0.090 0.02 2.61 2,345 27,355 708,432 0 0 27,355 0.63 451.04 18 270 4.50 0.7 0.123 0.381 0.105 0.02 3.04 2,736 30,091 708,525 0 0 30,091 0.69 451.04 19 285 4.75 0.7 0.123 0.376 0.105 0.02 3.04 2,736 32,827 708,618 0 0 32,827 0.75 451.04 20 300 5.00 0.8 0.141 0.372 0.120 0.02 3.47 3,126 35,953 708,724 0 0 35,953 0.83 451.05 21 315 5.25 0.6 0.106 0.367 0.090 0.02 2.61 2,345 38,298 708,803 0 0 38,298 0.88 451.05 22 330 5.50 0.7 0.123 0.362 0.105 0.02 3.04 2,736 41,033 708,896 0 0 41,033 0.94 451.05 23 345 5.75 0.8 0.141 0.357 0.120 0.02 3.47 3,126 44,160 709,002 0 0 44,160 1.01 451.06 24 360 6.00 0.8 0.141 0.352 0.120 0.02 3.47 3,126 47,286 709,108 0 0 47,286 1.09 451.06 25 375 6.25 0.9 0.159 0.348 0.135 0.02 3.91 3,517 50,803 709,227 0 0 50,803 1.17 451.07 26 390 6.50 0.9 0.159 0.343 0.135 0.02 3.91 3,517 54,320 709,347 0 0 54,320 1.25 451.07 27 405 6.75 1.0 0.176 0.339 0.150 0.03 4.34 3,908 58,228 709,479 0 0 58,228 1.34 451.08 28 420 7.00 1.0 0.176 0.334 0.150 0.03 4.34 3,908 62,136 709,612 0 0 62,136 1.43 451.08 29 435 7.25 1.0 0.176 0.329 0.150 0.03 4.34 3,908 66,044 709,744 0 0 66,044 1.52 451.09 30 450 7.50 1.1 0.194 0.325 0.165 0.03 4.78 4,299 70,343 709,890 0 0 70,343 1.61 451.09 31 465 7.75 1.2 0.212 0.320 0.180 0.03 5.21 4,690 75,032 710,049 0 0 75,032 1.72 451.10 32 480 8.00 1.3 0.229 0.316 0.195 0.03 5.64 5,080 80,112 710,221 0 0 80,112 1.84 451.11 33 495 8.25 1.5 0.265 0.312 0.225 0.04 6.51 5,862 85,974 710,420 0 0 85,974 1.97 451.11 34 510 8.50 1.5 0.265 0.307 0.225 0.04 6.51 5,862 91,836 710,619 0 0 91,836 2.11 451.12 35 525 8.75 1.6 0.282 0.303 0.240 0.04 6.95 6,253 98,089 710,831 0 0 98,089 2.25 451.13 36 540 9.00 1.7 0.300 0.299 0.255 0.00 0.18 165 98,254 710,836 0 0 98,254 2.26 451.13 37 555 9.25 1.9 0.335 0.295 0.285 0.04 6.67 6,000 104,254 711,040 0 0 104,254 2.39 451.14 38 570 9.50 2.0 0.353 0.290 0.300 0.06 10.25 9,224 113,478 711,352 0 0 113,478 2.61 451.15 39 585 9.75 2.1 0.370 0.286 0.315 0.08 13.83 12,443 125,920 711,774 0 0 125,920 2.89 451.17 40 600 10.00 2.2 0.388 0.282 0.330 0.11 17.39 15,655 141,576 712,305 0 0 141,576 3.25 451.19 41 615 10.25 1.5 0.265 0.278 0.225 0.04 6.51 5,862 147,438 712,504 0 0 147,438 3.38 451.19 42 630 10.50 1.5 0.265 0.274 0.225 0.04 6.51 5,862 153,299 712,703 0 0 153,299 3.52 451.20 43 645 10.75 2.0 0.353 0.270 0.300 0.08 13.59 12,231 165,530 713,117 0 0 165,530 3.80 451.22 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 162.75 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.13 LAG TIME - MINUTES 2.45 C 0.00246 Maxwell Drywells UNIT TIME-PERCENT OF LAG 612%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 44 660 11.00 2.0 0.353 0.266 0.300 0.09 14.24 12,815 178,345 713,552 0 0 178,345 4.09 451.24 45 675 11.25 1.9 0.335 0.262 0.285 0.07 11.99 10,787 189,132 713,917 0 0 189,132 4.34 451.25 46 690 11.50 1.9 0.335 0.258 0.285 0.08 12.62 11,358 200,490 714,302 0 0 200,490 4.60 451.26 47 705 11.75 1.7 0.300 0.254 0.255 0.05 7.46 6,712 207,202 714,530 0 0 207,202 4.76 451.27 48 720 12.00 1.8 0.318 0.251 0.270 0.07 10.97 9,877 217,079 714,865 0 0 217,079 4.98 451.29 49 735 12.25 2.5 0.441 0.247 0.375 0.19 31.85 28,666 245,745 715,837 0 0 245,745 5.64 451.32 50 750 12.50 2.6 0.459 0.243 0.390 0.22 35.35 31,818 277,562 716,916 0 0 277,562 6.37 451.37 51 765 12.75 2.8 0.494 0.240 0.420 0.25 41.74 37,568 315,130 718,189 0 0 315,130 7.23 451.42 52 780 13.00 2.9 0.512 0.236 0.435 0.28 45.23 40,706 355,837 719,569 0 0 355,837 8.17 451.47 53 795 13.25 3.4 0.600 0.232 0.510 0.37 60.29 54,260 410,096 721,409 0 0 410,096 9.41 451.54 54 810 13.50 3.4 0.600 0.229 0.510 0.37 60.87 54,780 464,876 723,266 0 0 464,876 10.67 451.61 55 825 13.75 2.3 0.406 0.225 0.345 0.18 29.59 26,635 491,511 724,169 0 0 491,511 11.28 451.65 56 840 14.00 2.3 0.406 0.222 0.345 0.18 30.16 27,142 518,652 725,090 0 0 518,652 11.91 451.68 57 855 14.25 2.7 0.476 0.219 0.405 0.26 42.29 38,063 556,715 726,380 0 0 556,715 12.78 451.73 58 870 14.50 2.6 0.459 0.215 0.390 0.24 39.94 35,950 592,665 727,599 0 0 592,665 13.61 451.78 59 885 14.75 2.6 0.459 0.212 0.390 0.25 40.48 36,436 629,101 728,834 0 0 629,101 14.44 451.83 60 900 15.00 2.5 0.441 0.209 0.375 0.23 38.12 34,310 663,411 729,998 0 0 663,411 15.23 451.87 61 915 15.25 2.4 0.423 0.206 0.360 0.22 35.75 32,176 695,587 731,088 0 0 695,587 15.97 451.92 62 930 15.50 2.3 0.406 0.202 0.345 0.20 33.37 30,035 725,622 732,107 0 0 725,622 16.66 451.96 63 945 15.75 1.9 0.335 0.199 0.285 0.14 22.30 20,071 745,693 732,787 0 0 745,693 17.12 451.98 64 960 16.00 1.9 0.335 0.196 0.285 0.14 22.80 20,521 766,214 733,483 0 0 766,214 17.59 452.01 65 975 16.25 0.4 0.071 0.193 0.060 0.01 1.74 1,563 767,777 733,536 0 0 767,777 17.63 452.01 66 990 16.50 0.4 0.071 0.190 0.060 0.01 1.74 1,563 769,340 733,589 0 0 769,340 17.66 452.01 67 1005 16.75 0.3 0.053 0.187 0.045 0.01 1.30 1,172 770,512 733,629 0 0 770,512 17.69 452.02 68 1020 17.00 0.3 0.053 0.185 0.045 0.01 1.30 1,172 771,685 733,668 0 0 771,685 17.72 452.02 69 1035 17.25 0.5 0.088 0.182 0.075 0.01 2.17 1,954 773,639 733,735 0 0 773,639 17.76 452.02 70 1050 17.50 0.5 0.088 0.179 0.075 0.01 2.17 1,954 775,593 733,801 0 0 775,593 17.81 452.02 71 1065 17.75 0.5 0.088 0.176 0.075 0.01 2.17 1,954 777,547 733,867 0 0 777,547 17.85 452.03 72 1080 18.00 0.4 0.071 0.174 0.060 0.01 1.74 1,563 779,110 733,920 0 0 779,110 17.89 452.03 73 1095 18.25 0.4 0.071 0.171 0.060 0.01 1.74 1,563 780,673 733,973 0 0 780,673 17.92 452.03 74 1110 18.50 0.4 0.071 0.169 0.060 0.01 1.74 1,563 782,236 734,026 0 0 782,236 17.96 452.03 75 1125 18.75 0.3 0.053 0.166 0.045 0.01 1.30 1,172 783,409 734,066 0 0 783,409 17.98 452.03 76 1140 19.00 0.2 0.035 0.164 0.030 0.01 0.87 782 784,190 734,092 0 0 784,190 18.00 452.03 77 1155 19.25 0.3 0.053 0.162 0.045 0.01 1.30 1,172 785,363 734,132 0 0 785,363 18.03 452.04 78 1170 19.50 0.4 0.071 0.159 0.060 0.01 1.74 1,563 786,926 734,185 0 0 786,926 18.07 452.04 79 1185 19.75 0.3 0.053 0.157 0.045 0.01 1.30 1,172 788,098 734,225 0 0 788,098 18.09 452.04 80 1200 20.00 0.2 0.035 0.155 0.030 0.01 0.87 782 788,880 734,251 0 0 788,880 18.11 452.04 81 1215 20.25 0.3 0.053 0.153 0.045 0.01 1.30 1,172 790,052 734,291 0 0 790,052 18.14 452.04 82 1230 20.50 0.3 0.053 0.151 0.045 0.01 1.30 1,172 791,224 734,331 0 0 791,224 18.16 452.04 83 1245 20.75 0.3 0.053 0.149 0.045 0.01 1.30 1,172 792,397 734,371 0 0 792,397 18.19 452.04 84 1260 21.00 0.2 0.035 0.147 0.030 0.01 0.87 782 793,178 734,397 0 0 793,178 18.21 452.05 85 1275 21.25 0.3 0.053 0.146 0.045 0.01 1.30 1,172 794,351 734,437 0 0 794,351 18.24 452.05 86 1290 21.50 0.2 0.035 0.144 0.030 0.01 0.87 782 795,132 734,463 0 0 795,132 18.25 452.05 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 162.75 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.13 LAG TIME - MINUTES 2.45 C 0.00246 Maxwell Drywells UNIT TIME-PERCENT OF LAG 612%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 87 1305 21.75 0.3 0.053 0.142 0.045 0.01 1.30 1,172 796,305 734,503 0 0 796,305 18.28 452.05 88 1320 22.00 0.2 0.035 0.141 0.030 0.01 0.87 782 797,086 734,530 0 0 797,086 18.30 452.05 89 1335 22.25 0.3 0.053 0.139 0.045 0.01 1.30 1,172 798,259 734,569 0 0 798,259 18.33 452.05 90 1350 22.50 0.2 0.035 0.138 0.030 0.01 0.87 782 799,040 734,596 0 0 799,040 18.34 452.05 91 1365 22.75 0.2 0.035 0.137 0.030 0.01 0.87 782 799,822 734,622 0 0 799,822 18.36 452.05 92 1380 23.00 0.2 0.035 0.136 0.030 0.01 0.87 782 800,603 734,649 0 0 800,603 18.38 452.06 93 1395 23.25 0.2 0.035 0.135 0.030 0.01 0.87 782 801,385 734,675 0 0 801,385 18.40 452.06 94 1410 23.50 0.2 0.035 0.134 0.030 0.01 0.87 782 802,167 734,702 0 0 802,167 18.42 452.06 95 1425 23.75 0.2 0.035 0.133 0.030 0.01 0.87 782 802,948 734,728 0 0 802,948 18.43 452.06 96 1440 24.00 0.2 0.035 0.133 0.030 0.01 0.87 782 803,730 734,755 0 0 803,730 18.45 452.06 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 4.41 in 2,605,281 cu-ft 1,801,551 cu-ft 452.06 ft 60.87 cfs 0 cu-ft 0.00 cf/min 1.36 in 18.45 acft 803,730 cu-ft 18.45 acft 803,730 cu-ft Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 451 0 0 707,505 0 0 0.00 455 4 4 102,845 810,350 3,033,385 3,033,385 69.64 WHERE: TOTAL WAVE LAGOON BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 1 B COMMERCIAL 1.483 D 56 0.51 0.90 2 B PAVING/HARDSCAPE 2.574 D 56 0.51 1.00 3 B WATER FEATURE 6.423 D 56 0.51 1.00 4 B SF - LOW DENSITY 20.347 D 56 0.51 0.30 5 B SF - MEDIUM DENSITY 0.000 D 56 0.51 0.40 6 B SF - HIGH DENSITY 0.000 D 56 0.51 0.50 9 B LANDSCAPING 10.759 D 56 0.51 0.10 2,000 ft 1,000 ft 485.0 ft ELEVATION OF CONCENTRATION POINT 460.2 ft 0.02 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 458.0 ft 279,800 sf 459.0 ft 304,405 sf PERCOLATION RATE (in/hr)0.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-B RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 BASIN B AMC NUMBER Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)217,379 323,050 416,643 665,724 SOIL LOSSES (cu-ft)47,811 140,132 235,776 499,505 EFFECTIVE RAIN (in)1.12 1.21 1.20 1.10 FLOOD VOLUME (cu-ft)169,568 182,917 180,867 166,219 (acre-ft)3.89 4.20 4.15 3.82 REQUIRED STORAGE (cu-ft)169,568 182,917 180,867 166,219 (acre-ft)3.89 4.20 4.15 3.82 FACTOR OF SAFETY 1.72 1.60 1.61 1.76 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 75.02 64.49 13.72 MAXIMUM WSEL (ft)458.58 458.63 458.62 458.57 DEPTH (ft)0.58 0.63 0.62 0.57 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days) [18] 200% OF LAG-MINUTES RAINFALL DATA 9.6 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 292,016 6.70 0.02 [17] 100% OF LAG-MINUTES 4.8 4.8 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.08 [16] LAG TIME-MINUTES [13] L*LCA/S^0.5 8.09 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.009 1000.00 [12] S^0.5 0.189 65.5 485 460.2 24.8 [3] AREA - ACRES [4] L-FEET [5] L-MILES 2000 0.379 BASIN B DA-B CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 41.586 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 90%0.10 1.483 0.036 0.0035 DEVELOPED 0.1800 0.0064 B 56 0.51 100%0.05 2.574 0.062 0.0032 DEVELOPED 0.1000 0.0062 B 56 0.51 100%0.05 6.423 0.154 0.0079 DEVELOPED 0.1000 0.0154 B 56 0.51 30%0.37 20.347 0.489 0.1822 DEVELOPED 0.6600 0.3229 B 56 0.51 40%0.33 0.000 0.000 0.0000 DEVELOPED 0.5800 0.0000 B 56 0.51 50%0.28 0.000 0.000 0.0000 DEVELOPED 0.5000 0.0000 B 56 0.51 10%0.46 10.759 0.259 0.1201 DEVELOPED 0.8200 0.2121 SUM 41.586 SUM 0.3167 0.5631 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.158358458 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00293 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00293 0.16 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.3167 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. SF - MEDIUM DENSITY SF - HIGH DENSITY LANDSCAPING (24-(T/60))^1.55 + LAND USE COMMERCIAL PAVING/HARDSCAPE WATER FEATURE SF - LOW DENSITY AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 41.59 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 4.78 Maxwell Drywells UNIT TIME-PERCENT OF LAG 104.6 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.32 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.32 0.53 0.31 12.80 3,841 3,841 280,124 0 0 3,841 0.09 458.01 2 10 0.17 4.2 0.73 0.32 0.62 0.41 17.15 5,146 8,987 280,557 0 0 8,987 0.21 458.03 3 15 0.25 4.4 0.76 0.32 0.65 0.44 18.60 5,580 14,568 281,027 0 0 14,568 0.33 458.05 4 20 0.33 4.6 0.79 0.32 0.68 0.48 20.05 6,015 20,583 281,534 0 0 20,583 0.47 458.07 5 25 0.42 5.0 0.86 0.32 0.73 0.55 22.95 6,885 27,467 282,114 0 0 27,467 0.63 458.09 6 30 0.50 5.6 0.97 0.32 0.82 0.65 27.30 8,189 35,656 282,804 0 0 35,656 0.82 458.12 7 35 0.58 6.4 1.11 0.32 0.94 0.79 33.09 9,928 45,584 283,641 0 0 45,584 1.05 458.16 8 40 0.67 8.1 1.40 0.32 1.19 1.08 45.41 13,623 59,208 284,789 0 0 59,208 1.36 458.20 9 45 0.75 13.1 2.26 0.32 1.92 1.95 81.64 24,492 83,700 286,853 0 0 83,700 1.92 458.29 10 50 0.83 34.5 5.96 0.32 5.07 5.64 236.71 71,012 154,712 292,836 0 0 154,712 3.55 458.53 11 55 0.92 6.7 1.16 0.32 0.98 0.84 35.27 10,580 165,292 293,727 0 0 165,292 3.79 458.57 12 60 1.00 3.8 0.66 0.32 0.56 0.34 14.25 4,276 169,568 294,088 0 0 169,568 3.89 458.58 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 217,379 cu-ft SOIL LOSSES 47,811 cu-ft EFFECTIVE RAIN 1.12 in FLOOD VOLUME 3.89 acft FLOOD VOLUME 169,568 cu-ft REQUIRED STORAGE 3.89 REQUIRED STORAGE 169,568 cu-ft MAX WSEL 458.58 ft PEAK FLOW RATE 236.71 cfs TOTAL BASIN LOSSES 0 cu-ft AVERAGE PERCOLATION RATE 0.00 cf/min EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 41.59 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 4.78 Maxwell Drywells UNIT TIME-PERCENT OF LAG 104.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.32 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.32 0.28 0.02 0.72 215 215 279,818 0 0 215 0.00 458.00 2 10 0.17 1.3 0.33 0.32 0.28 0.02 0.72 215 431 279,836 0 0 431 0.01 458.00 3 15 0.25 1.1 0.28 0.32 0.24 0.04 1.78 533 964 279,881 0 0 964 0.02 458.00 4 20 0.33 1.5 0.39 0.32 0.33 0.07 2.87 862 1,825 279,954 0 0 1,825 0.04 458.01 5 25 0.42 1.5 0.39 0.32 0.33 0.07 2.87 862 2,687 280,026 0 0 2,687 0.06 458.01 6 30 0.50 1.8 0.46 0.32 0.39 0.15 6.10 1,831 4,518 280,181 0 0 4,518 0.10 458.02 7 35 0.58 1.5 0.39 0.32 0.33 0.07 2.87 862 5,379 280,253 0 0 5,379 0.12 458.02 8 40 0.67 1.8 0.46 0.32 0.39 0.15 6.10 1,831 7,210 280,407 0 0 7,210 0.17 458.02 9 45 0.75 1.8 0.46 0.32 0.39 0.15 6.10 1,831 9,040 280,562 0 0 9,040 0.21 458.03 10 50 0.83 1.5 0.39 0.32 0.33 0.07 2.87 862 9,902 280,634 0 0 9,902 0.23 458.03 11 55 0.92 1.6 0.41 0.32 0.35 0.09 3.95 1,185 11,086 280,734 0 0 11,086 0.25 458.04 12 60 1.00 1.8 0.46 0.32 0.39 0.15 6.10 1,831 12,917 280,888 0 0 12,917 0.30 458.04 13 65 1.08 2.2 0.56 0.32 0.48 0.25 10.41 3,123 16,040 281,152 0 0 16,040 0.37 458.05 14 70 1.17 2.2 0.56 0.32 0.48 0.25 10.41 3,123 19,163 281,415 0 0 19,163 0.44 458.07 15 75 1.25 2.2 0.56 0.32 0.48 0.25 10.41 3,123 22,286 281,678 0 0 22,286 0.51 458.08 16 80 1.33 2.0 0.51 0.32 0.44 0.20 8.26 2,477 24,762 281,886 0 0 24,762 0.57 458.08 17 85 1.42 2.6 0.67 0.32 0.57 0.35 14.72 4,415 29,177 282,258 0 0 29,177 0.67 458.10 18 90 1.50 2.7 0.69 0.32 0.59 0.38 15.79 4,738 33,915 282,658 0 0 33,915 0.78 458.12 19 95 1.58 2.4 0.62 0.32 0.52 0.30 12.56 3,769 37,684 282,975 0 0 37,684 0.87 458.13 20 100 1.67 2.7 0.69 0.32 0.59 0.38 15.79 4,738 42,423 283,374 0 0 42,423 0.97 458.15 21 105 1.75 3.3 0.85 0.32 0.72 0.53 22.25 6,676 49,099 283,937 0 0 49,099 1.13 458.17 22 110 1.83 3.1 0.80 0.32 0.68 0.48 20.10 6,030 55,129 284,445 0 0 55,129 1.27 458.19 23 115 1.92 2.9 0.74 0.32 0.63 0.43 17.95 5,384 60,513 284,899 0 0 60,513 1.39 458.21 24 120 2.00 3.0 0.77 0.32 0.65 0.45 19.02 5,707 66,221 285,380 0 0 66,221 1.52 458.23 25 125 2.08 3.1 0.80 0.32 0.68 0.48 20.10 6,030 72,251 285,888 0 0 72,251 1.66 458.25 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 41.59 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 4.78 Maxwell Drywells UNIT TIME-PERCENT OF LAG 104.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.32 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses 26 130 2.17 4.2 1.08 0.32 0.92 0.76 31.95 9,584 81,835 286,695 0 0 81,835 1.88 458.28 27 135 2.25 5.0 1.28 0.32 1.09 0.97 40.56 12,168 94,003 287,721 0 0 94,003 2.16 458.32 28 140 2.33 3.5 0.90 0.32 0.76 0.58 24.41 7,322 101,326 288,338 0 0 101,326 2.33 458.35 29 145 2.42 6.8 1.75 0.32 1.48 1.43 59.94 17,983 119,309 289,853 0 0 119,309 2.74 458.41 30 150 2.50 7.3 1.87 0.32 1.59 1.56 65.33 19,598 138,907 291,504 0 0 138,907 3.19 458.48 31 155 2.58 8.2 2.11 0.32 1.79 1.79 75.02 22,506 161,413 293,400 0 0 161,413 3.71 458.55 32 160 2.67 5.9 1.52 0.32 1.29 1.20 50.25 15,076 176,489 294,671 0 0 176,489 4.05 458.60 33 165 2.75 2.0 0.51 0.32 0.44 0.20 8.26 2,477 178,965 294,879 0 0 178,965 4.11 458.61 34 170 2.83 1.8 0.46 0.32 0.39 0.15 6.10 1,831 180,796 295,034 0 0 180,796 4.15 458.62 35 175 2.92 1.8 0.46 0.32 0.39 0.15 6.10 1,831 182,627 295,188 0 0 182,627 4.19 458.63 36 180 3.00 0.6 0.15 0.32 0.13 0.02 0.97 291 182,917 295,212 0 0 182,917 4.20 458.63 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY 0 cu-ft 0.00 cf/min 1.21 in 4.20 acft 182,917 cu-ft 4.20 acft 182,917 cu-ft 140,132 cu-ft 2.14 in 323,050 cu-ft 458.63 ft 75.02 cfs Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 41.59 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 4.78 Maxwell Drywells UNIT TIME-PERCENT OF LAG 104.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.32 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.32 0.14 0.02 1.04 312 312 279,826 0 0 312 0.01 458.00 2 10 0.17 0.6 0.20 0.32 0.17 0.03 1.25 375 687 279,858 0 0 687 0.02 458.00 3 15 0.25 0.6 0.20 0.32 0.17 0.03 1.25 375 1,062 279,890 0 0 1,062 0.02 458.00 4 20 0.33 0.6 0.20 0.32 0.17 0.03 1.25 375 1,437 279,921 0 0 1,437 0.03 458.00 5 25 0.42 0.6 0.20 0.32 0.17 0.03 1.25 375 1,812 279,953 0 0 1,812 0.04 458.01 6 30 0.50 0.7 0.23 0.32 0.20 0.03 1.46 437 2,250 279,990 0 0 2,250 0.05 458.01 7 35 0.58 0.7 0.23 0.32 0.20 0.03 1.46 437 2,687 280,026 0 0 2,687 0.06 458.01 8 40 0.67 0.7 0.23 0.32 0.20 0.03 1.46 437 3,125 280,063 0 0 3,125 0.07 458.01 9 45 0.75 0.7 0.23 0.32 0.20 0.03 1.46 437 3,562 280,100 0 0 3,562 0.08 458.01 10 50 0.83 0.7 0.23 0.32 0.20 0.03 1.46 437 4,000 280,137 0 0 4,000 0.09 458.01 11 55 0.92 0.7 0.23 0.32 0.20 0.03 1.46 437 4,437 280,174 0 0 4,437 0.10 458.02 12 60 1.00 0.8 0.26 0.32 0.23 0.04 1.67 500 4,937 280,216 0 0 4,937 0.11 458.02 13 65 1.08 0.8 0.26 0.32 0.23 0.04 1.67 500 5,437 280,258 0 0 5,437 0.12 458.02 14 70 1.17 0.8 0.26 0.32 0.23 0.04 1.67 500 5,937 280,300 0 0 5,937 0.14 458.02 15 75 1.25 0.8 0.26 0.32 0.23 0.04 1.67 500 6,437 280,342 0 0 6,437 0.15 458.02 16 80 1.33 0.8 0.26 0.32 0.23 0.04 1.67 500 6,937 280,385 0 0 6,937 0.16 458.02 17 85 1.42 0.8 0.26 0.32 0.23 0.04 1.67 500 7,437 280,427 0 0 7,437 0.17 458.03 18 90 1.50 0.8 0.26 0.32 0.23 0.04 1.67 500 7,937 280,469 0 0 7,937 0.18 458.03 19 95 1.58 0.8 0.26 0.32 0.23 0.04 1.67 500 8,437 280,511 0 0 8,437 0.19 458.03 20 100 1.67 0.8 0.26 0.32 0.23 0.04 1.67 500 8,937 280,553 0 0 8,937 0.21 458.03 21 105 1.75 0.8 0.26 0.32 0.23 0.04 1.67 500 9,437 280,595 0 0 9,437 0.22 458.03 22 110 1.83 0.8 0.26 0.32 0.23 0.04 1.67 500 9,937 280,637 0 0 9,937 0.23 458.03 23 115 1.92 0.8 0.26 0.32 0.23 0.04 1.67 500 10,437 280,679 0 0 10,437 0.24 458.04 24 120 2.00 0.9 0.30 0.32 0.25 0.04 1.87 562 10,999 280,727 0 0 10,999 0.25 458.04 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 41.59 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 4.78 Maxwell Drywells UNIT TIME-PERCENT OF LAG 104.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.32 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.32 0.23 0.04 1.67 500 11,499 280,769 0 0 11,499 0.26 458.04 26 130 2.17 0.9 0.30 0.32 0.25 0.04 1.87 562 12,062 280,816 0 0 12,062 0.28 458.04 27 135 2.25 0.9 0.30 0.32 0.25 0.04 1.87 562 12,624 280,864 0 0 12,624 0.29 458.04 28 140 2.33 0.9 0.30 0.32 0.25 0.04 1.87 562 13,187 280,911 0 0 13,187 0.30 458.05 29 145 2.42 0.9 0.30 0.32 0.25 0.04 1.87 562 13,749 280,958 0 0 13,749 0.32 458.05 30 150 2.50 0.9 0.30 0.32 0.25 0.04 1.87 562 14,312 281,006 0 0 14,312 0.33 458.05 31 155 2.58 0.9 0.30 0.32 0.25 0.04 1.87 562 14,874 281,053 0 0 14,874 0.34 458.05 32 160 2.67 0.9 0.30 0.32 0.25 0.04 1.87 562 15,437 281,101 0 0 15,437 0.35 458.05 33 165 2.75 1.0 0.33 0.32 0.28 0.01 0.61 182 15,619 281,116 0 0 15,619 0.36 458.05 34 170 2.83 1.0 0.33 0.32 0.28 0.01 0.61 182 15,801 281,131 0 0 15,801 0.36 458.05 35 175 2.92 1.0 0.33 0.32 0.28 0.01 0.61 182 15,983 281,147 0 0 15,983 0.37 458.05 36 180 3.00 1.0 0.33 0.32 0.28 0.01 0.61 182 16,165 281,162 0 0 16,165 0.37 458.06 37 185 3.08 1.0 0.33 0.32 0.28 0.01 0.61 182 16,348 281,177 0 0 16,348 0.38 458.06 38 190 3.17 1.1 0.36 0.32 0.31 0.05 2.00 599 16,946 281,228 0 0 16,946 0.39 458.06 39 195 3.25 1.1 0.36 0.32 0.31 0.05 2.00 599 17,545 281,278 0 0 17,545 0.40 458.06 40 200 3.33 1.1 0.36 0.32 0.31 0.05 2.00 599 18,144 281,329 0 0 18,144 0.42 458.06 41 205 3.42 1.2 0.40 0.32 0.34 0.08 3.38 1,015 19,160 281,414 0 0 19,160 0.44 458.07 42 210 3.50 1.3 0.43 0.32 0.37 0.11 4.77 1,432 20,592 281,535 0 0 20,592 0.47 458.07 43 215 3.58 1.4 0.46 0.32 0.39 0.15 6.16 1,849 22,441 281,691 0 0 22,441 0.52 458.08 44 220 3.67 1.4 0.46 0.32 0.39 0.15 6.16 1,849 24,289 281,847 0 0 24,289 0.56 458.08 45 225 3.75 1.5 0.50 0.32 0.42 0.18 7.55 2,265 26,555 282,037 0 0 26,555 0.61 458.09 46 230 3.83 1.5 0.50 0.32 0.42 0.18 7.55 2,265 28,820 282,228 0 0 28,820 0.66 458.10 47 235 3.92 1.6 0.53 0.32 0.45 0.21 8.94 2,682 31,502 282,454 0 0 31,502 0.72 458.11 48 240 4.00 1.6 0.53 0.32 0.45 0.21 8.94 2,682 34,184 282,680 0 0 34,184 0.78 458.12 49 245 4.08 1.7 0.56 0.32 0.48 0.25 10.33 3,099 37,283 282,941 0 0 37,283 0.86 458.13 50 250 4.17 1.8 0.60 0.32 0.51 0.28 11.72 3,515 40,798 283,238 0 0 40,798 0.94 458.14 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 41.59 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 4.78 Maxwell Drywells UNIT TIME-PERCENT OF LAG 104.6 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.32 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.32 0.53 0.31 13.11 3,932 44,730 283,569 0 0 44,730 1.03 458.15 52 260 4.33 2.0 0.66 0.32 0.56 0.35 14.50 4,349 49,079 283,935 0 0 49,079 1.13 458.17 53 265 4.42 2.1 0.70 0.32 0.59 0.38 15.88 4,765 53,844 284,337 0 0 53,844 1.24 458.18 54 270 4.50 2.1 0.70 0.32 0.59 0.38 15.88 4,765 58,609 284,738 0 0 58,609 1.35 458.20 55 275 4.58 2.2 0.73 0.32 0.62 0.41 17.27 5,182 63,791 285,175 0 0 63,791 1.46 458.22 56 280 4.67 2.3 0.76 0.32 0.65 0.45 18.66 5,599 69,390 285,647 0 0 69,390 1.59 458.24 57 285 4.75 2.4 0.79 0.32 0.68 0.48 20.05 6,015 75,405 286,154 0 0 75,405 1.73 458.26 58 290 4.83 2.4 0.79 0.32 0.68 0.48 20.05 6,015 81,420 286,660 0 0 81,420 1.87 458.28 59 295 4.92 2.5 0.83 0.32 0.70 0.51 21.44 6,432 87,852 287,202 0 0 87,852 2.02 458.30 60 300 5.00 2.6 0.86 0.32 0.73 0.54 22.83 6,848 94,701 287,779 0 0 94,701 2.17 458.32 61 305 5.08 3.1 1.03 0.32 0.87 0.71 29.77 8,932 103,632 288,532 0 0 103,632 2.38 458.35 62 310 5.17 3.6 1.19 0.32 1.01 0.88 36.72 11,015 114,647 289,460 0 0 114,647 2.63 458.39 63 315 5.25 3.9 1.29 0.32 1.10 0.97 40.88 12,265 126,912 290,493 0 0 126,912 2.91 458.43 64 320 5.33 4.2 1.39 0.32 1.18 1.07 45.05 13,515 140,427 291,632 0 0 140,427 3.22 458.48 65 325 5.42 4.7 1.56 0.32 1.32 1.24 51.99 15,598 156,025 292,947 0 0 156,025 3.58 458.53 66 330 5.50 5.6 1.85 0.32 1.58 1.54 64.49 19,348 175,373 294,577 0 0 175,373 4.03 458.60 67 335 5.58 1.9 0.63 0.32 0.53 0.31 13.11 3,932 179,305 294,908 0 0 179,305 4.12 458.61 68 340 5.67 0.9 0.30 0.32 0.25 0.04 1.87 562 179,867 294,955 0 0 179,867 4.13 458.62 69 345 5.75 0.6 0.20 0.32 0.17 0.03 1.25 375 180,242 294,987 0 0 180,242 4.14 458.62 70 350 5.83 0.5 0.17 0.32 0.14 0.02 1.04 312 180,555 295,013 0 0 180,555 4.14 458.62 71 355 5.92 0.3 0.10 0.32 0.08 0.01 0.62 187 180,742 295,029 0 0 180,742 4.15 458.62 72 360 6.00 0.2 0.07 0.32 0.06 0.01 0.42 125 180,867 295,040 0 0 180,867 4.15 458.62 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY 0.00 cf/min 0 cu-ft 1.20 in 4.15 acft 180,867 cu-ft 4.15 acft 180,867 cu-ft 416,643 cu-ft 2.76 in 235,776 cu-ft 458.62 ft 64.49 cfs Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 41.59 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.16 LAG TIME - MINUTES 4.78 C 0.00293 Maxwell Drywells UNIT TIME-PERCENT OF LAG 314%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.559 0.030 0.01 0.22 200 200 279,817 0 0 200 0.00 458.00 2 30 0.50 0.3 0.053 0.553 0.045 0.01 0.33 300 499 279,842 0 0 499 0.01 458.00 3 45 0.75 0.3 0.053 0.546 0.045 0.01 0.33 300 799 279,867 0 0 799 0.02 458.00 4 60 1.00 0.4 0.071 0.540 0.060 0.01 0.44 399 1,198 279,901 0 0 1,198 0.03 458.00 5 75 1.25 0.3 0.053 0.534 0.045 0.01 0.33 300 1,498 279,926 0 0 1,498 0.03 458.01 6 90 1.50 0.3 0.053 0.527 0.045 0.01 0.33 300 1,797 279,951 0 0 1,797 0.04 458.01 7 105 1.75 0.3 0.053 0.521 0.045 0.01 0.33 300 2,097 279,977 0 0 2,097 0.05 458.01 8 120 2.00 0.4 0.071 0.515 0.060 0.01 0.44 399 2,496 280,010 0 0 2,496 0.06 458.01 9 135 2.25 0.4 0.071 0.508 0.060 0.01 0.44 399 2,896 280,044 0 0 2,896 0.07 458.01 10 150 2.50 0.4 0.071 0.502 0.060 0.01 0.44 399 3,295 280,078 0 0 3,295 0.08 458.01 11 165 2.75 0.5 0.088 0.496 0.075 0.01 0.55 499 3,795 280,120 0 0 3,795 0.09 458.01 12 180 3.00 0.5 0.088 0.490 0.075 0.01 0.55 499 4,294 280,162 0 0 4,294 0.10 458.01 13 195 3.25 0.5 0.088 0.484 0.075 0.01 0.55 499 4,793 280,204 0 0 4,793 0.11 458.02 14 210 3.50 0.5 0.088 0.478 0.075 0.01 0.55 499 5,293 280,246 0 0 5,293 0.12 458.02 15 225 3.75 0.5 0.088 0.472 0.075 0.01 0.55 499 5,792 280,288 0 0 5,792 0.13 458.02 16 240 4.00 0.6 0.106 0.466 0.090 0.02 0.67 599 6,391 280,338 0 0 6,391 0.15 458.02 17 255 4.25 0.6 0.106 0.460 0.090 0.02 0.67 599 6,990 280,389 0 0 6,990 0.16 458.02 18 270 4.50 0.7 0.123 0.454 0.105 0.02 0.78 699 7,689 280,448 0 0 7,689 0.18 458.03 19 285 4.75 0.7 0.123 0.448 0.105 0.02 0.78 699 8,388 280,507 0 0 8,388 0.19 458.03 20 300 5.00 0.8 0.141 0.443 0.120 0.02 0.89 799 9,187 280,574 0 0 9,187 0.21 458.03 21 315 5.25 0.6 0.106 0.437 0.090 0.02 0.67 599 9,786 280,625 0 0 9,786 0.22 458.03 22 330 5.50 0.7 0.123 0.431 0.105 0.02 0.78 699 10,485 280,683 0 0 10,485 0.24 458.04 23 345 5.75 0.8 0.141 0.426 0.120 0.02 0.89 799 11,284 280,751 0 0 11,284 0.26 458.04 24 360 6.00 0.8 0.141 0.420 0.120 0.02 0.89 799 12,083 280,818 0 0 12,083 0.28 458.04 25 375 6.25 0.9 0.159 0.414 0.135 0.02 1.00 899 12,982 280,894 0 0 12,982 0.30 458.04 26 390 6.50 0.9 0.159 0.409 0.135 0.02 1.00 899 13,880 280,970 0 0 13,880 0.32 458.05 27 405 6.75 1.0 0.176 0.403 0.150 0.03 1.11 999 14,879 281,054 0 0 14,879 0.34 458.05 28 420 7.00 1.0 0.176 0.398 0.150 0.03 1.11 999 15,878 281,138 0 0 15,878 0.36 458.05 29 435 7.25 1.0 0.176 0.392 0.150 0.03 1.11 999 16,876 281,222 0 0 16,876 0.39 458.06 30 450 7.50 1.1 0.194 0.387 0.165 0.03 1.22 1,098 17,975 281,315 0 0 17,975 0.41 458.06 31 465 7.75 1.2 0.212 0.382 0.180 0.03 1.33 1,198 19,173 281,415 0 0 19,173 0.44 458.07 32 480 8.00 1.3 0.229 0.377 0.195 0.03 1.44 1,298 20,471 281,525 0 0 20,471 0.47 458.07 33 495 8.25 1.5 0.265 0.371 0.225 0.04 1.66 1,498 21,969 281,651 0 0 21,969 0.50 458.08 34 510 8.50 1.5 0.265 0.366 0.225 0.04 1.66 1,498 23,467 281,777 0 0 23,467 0.54 458.08 35 525 8.75 1.6 0.282 0.361 0.240 0.04 1.78 1,598 25,064 281,912 0 0 25,064 0.58 458.09 36 540 9.00 1.7 0.300 0.356 0.255 0.04 1.89 1,698 26,762 282,055 0 0 26,762 0.61 458.09 37 555 9.25 1.9 0.335 0.351 0.285 0.05 2.11 1,897 28,659 282,215 0 0 28,659 0.66 458.10 38 570 9.50 2.0 0.353 0.346 0.300 0.01 0.29 260 28,919 282,237 0 0 28,919 0.66 458.10 39 585 9.75 2.1 0.370 0.341 0.315 0.03 1.24 1,112 30,031 282,330 0 0 30,031 0.69 458.10 40 600 10.00 2.2 0.388 0.336 0.330 0.05 2.18 1,963 31,994 282,496 0 0 31,994 0.73 458.11 41 615 10.25 1.5 0.265 0.331 0.225 0.04 1.66 1,498 33,492 282,622 0 0 33,492 0.77 458.11 42 630 10.50 1.5 0.265 0.326 0.225 0.04 1.66 1,498 34,989 282,748 0 0 34,989 0.80 458.12 43 645 10.75 2.0 0.353 0.322 0.300 0.03 1.31 1,175 36,164 282,847 0 0 36,164 0.83 458.12 in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 41.59 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.16 LAG TIME - MINUTES 4.78 C 0.00293 Maxwell Drywells UNIT TIME-PERCENT OF LAG 314%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses 44 660 11.00 2.0 0.353 0.317 0.300 0.04 1.50 1,353 37,517 282,961 0 0 37,517 0.86 458.13 45 675 11.25 1.9 0.335 0.312 0.285 0.02 0.96 863 38,380 283,034 0 0 38,380 0.88 458.13 46 690 11.50 1.9 0.335 0.308 0.285 0.03 1.15 1,037 39,416 283,121 0 0 39,416 0.90 458.13 47 705 11.75 1.7 0.300 0.303 0.255 0.04 1.89 1,698 41,114 283,264 0 0 41,114 0.94 458.14 48 720 12.00 1.8 0.318 0.299 0.270 0.02 0.79 713 41,827 283,324 0 0 41,827 0.96 458.14 49 735 12.25 2.5 0.441 0.294 0.375 0.15 6.16 5,541 47,368 283,791 0 0 47,368 1.09 458.16 50 750 12.50 2.6 0.459 0.290 0.390 0.17 7.08 6,373 53,742 284,328 0 0 53,742 1.23 458.18 51 765 12.75 2.8 0.494 0.285 0.420 0.21 8.74 7,869 61,611 284,991 0 0 61,611 1.41 458.21 52 780 13.00 2.9 0.512 0.281 0.435 0.23 9.66 8,697 70,308 285,724 0 0 70,308 1.61 458.24 53 795 13.25 3.4 0.600 0.277 0.510 0.32 13.54 12,186 82,494 286,751 0 0 82,494 1.89 458.28 54 810 13.50 3.4 0.600 0.273 0.510 0.33 13.72 12,345 94,839 287,791 0 0 94,839 2.18 458.32 55 825 13.75 2.3 0.406 0.269 0.345 0.14 5.75 5,178 100,017 288,227 0 0 100,017 2.30 458.34 56 840 14.00 2.3 0.406 0.264 0.345 0.14 5.92 5,332 105,349 288,677 0 0 105,349 2.42 458.36 57 855 14.25 2.7 0.476 0.260 0.405 0.22 9.05 8,147 113,496 289,363 0 0 113,496 2.61 458.39 58 870 14.50 2.6 0.459 0.256 0.390 0.20 8.48 7,632 121,128 290,006 0 0 121,128 2.78 458.41 59 885 14.75 2.6 0.459 0.253 0.390 0.21 8.64 7,779 128,907 290,662 0 0 128,907 2.96 458.44 60 900 15.00 2.5 0.441 0.249 0.375 0.19 8.07 7,259 136,166 291,273 0 0 136,166 3.13 458.47 61 915 15.25 2.4 0.423 0.245 0.360 0.18 7.49 6,737 142,904 291,841 0 0 142,904 3.28 458.49 62 930 15.50 2.3 0.406 0.241 0.345 0.16 6.90 6,213 149,117 292,364 0 0 149,117 3.42 458.51 63 945 15.75 1.9 0.335 0.237 0.285 0.10 4.10 3,689 152,806 292,675 0 0 152,806 3.51 458.52 64 960 16.00 1.9 0.335 0.234 0.285 0.10 4.25 3,826 156,632 292,998 0 0 156,632 3.60 458.54 65 975 16.25 0.4 0.071 0.230 0.060 0.01 0.44 399 157,032 293,031 0 0 157,032 3.60 458.54 66 990 16.50 0.4 0.071 0.227 0.060 0.01 0.44 399 157,431 293,065 0 0 157,431 3.61 458.54 67 1005 16.75 0.3 0.053 0.223 0.045 0.01 0.33 300 157,731 293,090 0 0 157,731 3.62 458.54 68 1020 17.00 0.3 0.053 0.220 0.045 0.01 0.33 300 158,030 293,115 0 0 158,030 3.63 458.54 69 1035 17.25 0.5 0.088 0.217 0.075 0.01 0.55 499 158,530 293,158 0 0 158,530 3.64 458.54 70 1050 17.50 0.5 0.088 0.213 0.075 0.01 0.55 499 159,029 293,200 0 0 159,029 3.65 458.54 71 1065 17.75 0.5 0.088 0.210 0.075 0.01 0.55 499 159,528 293,242 0 0 159,528 3.66 458.55 72 1080 18.00 0.4 0.071 0.207 0.060 0.01 0.44 399 159,928 293,275 0 0 159,928 3.67 458.55 73 1095 18.25 0.4 0.071 0.204 0.060 0.01 0.44 399 160,327 293,309 0 0 160,327 3.68 458.55 74 1110 18.50 0.4 0.071 0.201 0.060 0.01 0.44 399 160,726 293,343 0 0 160,726 3.69 458.55 75 1125 18.75 0.3 0.053 0.198 0.045 0.01 0.33 300 161,026 293,368 0 0 161,026 3.70 458.55 76 1140 19.00 0.2 0.035 0.195 0.030 0.01 0.22 200 161,226 293,385 0 0 161,226 3.70 458.55 77 1155 19.25 0.3 0.053 0.193 0.045 0.01 0.33 300 161,525 293,410 0 0 161,525 3.71 458.55 78 1170 19.50 0.4 0.071 0.190 0.060 0.01 0.44 399 161,925 293,444 0 0 161,925 3.72 458.55 79 1185 19.75 0.3 0.053 0.187 0.045 0.01 0.33 300 162,224 293,469 0 0 162,224 3.72 458.56 80 1200 20.00 0.2 0.035 0.185 0.030 0.01 0.22 200 162,424 293,486 0 0 162,424 3.73 458.56 81 1215 20.25 0.3 0.053 0.182 0.045 0.01 0.33 300 162,724 293,511 0 0 162,724 3.74 458.56 82 1230 20.50 0.3 0.053 0.180 0.045 0.01 0.33 300 163,023 293,536 0 0 163,023 3.74 458.56 83 1245 20.75 0.3 0.053 0.178 0.045 0.01 0.33 300 163,323 293,561 0 0 163,323 3.75 458.56 84 1260 21.00 0.2 0.035 0.176 0.030 0.01 0.22 200 163,523 293,578 0 0 163,523 3.75 458.56 85 1275 21.25 0.3 0.053 0.173 0.045 0.01 0.33 300 163,822 293,603 0 0 163,822 3.76 458.56 86 1290 21.50 0.2 0.035 0.171 0.030 0.01 0.22 200 164,022 293,620 0 0 164,022 3.77 458.56 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 41.59 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.16 LAG TIME - MINUTES 4.78 C 0.00293 Maxwell Drywells UNIT TIME-PERCENT OF LAG 314%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses 87 1305 21.75 0.3 0.053 0.170 0.045 0.01 0.33 300 164,321 293,646 0 0 164,321 3.77 458.56 88 1320 22.00 0.2 0.035 0.168 0.030 0.01 0.22 200 164,521 293,662 0 0 164,521 3.78 458.56 89 1335 22.25 0.3 0.053 0.166 0.045 0.01 0.33 300 164,821 293,688 0 0 164,821 3.78 458.56 90 1350 22.50 0.2 0.035 0.165 0.030 0.01 0.22 200 165,020 293,704 0 0 165,020 3.79 458.57 91 1365 22.75 0.2 0.035 0.163 0.030 0.01 0.22 200 165,220 293,721 0 0 165,220 3.79 458.57 92 1380 23.00 0.2 0.035 0.162 0.030 0.01 0.22 200 165,420 293,738 0 0 165,420 3.80 458.57 93 1395 23.25 0.2 0.035 0.161 0.030 0.01 0.22 200 165,620 293,755 0 0 165,620 3.80 458.57 94 1410 23.50 0.2 0.035 0.160 0.030 0.01 0.22 200 165,819 293,772 0 0 165,819 3.81 458.57 95 1425 23.75 0.2 0.035 0.159 0.030 0.01 0.22 200 166,019 293,789 0 0 166,019 3.81 458.57 96 1440 24.00 0.2 0.035 0.158 0.030 0.01 0.22 200 166,219 293,805 0 0 166,219 3.82 458.57 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 0 cu-ft 0.00 cf/min 1.10 in 3.82 acft 166,219 cu-ft 3.82 acft 166,219 cu-ft 4.41 in 665,724 cu-ft 499,505 cu-ft 458.57 ft 13.72 cfs Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 458 0 0 279,800 0 0 0.00 459 1 1 24,605 304,405 292,016 292,016 6.70 WHERE: TOTAL BASIN B BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 2 B PAVING/HARDSCAPE 1.455 D 56 0.51 1.00 5 B SF - MEDIUM DENSITY 4.092 D 56 0.51 0.40 6 B SF - HIGH DENSITY 2.159 D 56 0.51 0.50 9 B LANDSCAPING 2.485 D 56 0.51 0.10 2 B PAVING/HARDSCAPE 0.353 D 56 0.51 1.00 4 B SF - LOW DENSITY 42.760 D 56 0.51 0.30 9 B LANDSCAPING 1.698 D 56 0.51 0.10 1,350 ft 675 ft 464.0 ft ELEVATION OF CONCENTRATION POINT 455.0 ft 0.02 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 451.0 ft 65,060 sf 452.0 ft 71,195 sf 453.0 ft 77,490 sf 454.0 ft 83,940 sf PERCOLATION RATE (in/hr)1.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 BASIN F AMC NUMBER RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-C & DA-F Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)287,508 427,268 551,056 880,492 SOIL LOSSES (cu-ft)72,217 208,194 331,366 683,384 EFFECTIVE RAIN (in)1.08 1.10 1.10 0.99 FLOOD VOLUME (cu-ft)215,291 219,074 219,690 197,108 (acre-ft)4.94 5.03 5.04 4.52 REQUIRED STORAGE (cu-ft)209,295 201,651 186,456 112,227 (acre-ft)4.80 4.63 4.28 2.58 FACTOR OF SAFETY 1.07 1.11 1.20 1.99 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 96.73 82.80 15.99 MAXIMUM WSEL (ft)453.83 453.73 453.55 452.59 DEPTH (ft)2.83 2.73 2.55 1.59 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days)1.5 1.6 1.6 1.6 BASIN F DA-C & DA-F CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 55.002 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION [3] AREA - ACRES [4] L-FEET [5] L-MILES 1350 0.256 [13] L*LCA/S^0.5 5.93 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.006 675.00 [12] S^0.5 0.128 35.2 464 455 9 0.02 [17] 100% OF LAG-MINUTES 4.0 4.0 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.07 [16] LAG TIME-MINUTES [18] 200% OF LAG-MINUTES RAINFALL DATA 8.0 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 223,118 5.12 Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 100%0.05 1.455 0.026 0.0013 DEVELOPED 0.1000 0.0026 B 56 0.51 40%0.33 4.092 0.074 0.0243 DEVELOPED 0.5800 0.0432 B 56 0.51 50%0.28 2.159 0.039 0.0110 DEVELOPED 0.5000 0.0196 B 56 0.51 10%0.46 2.485 0.045 0.0210 DEVELOPED 0.8200 0.0370 B 56 0.51 100%0.05 0.353 0.006 0.0003 DEVELOPED 0.1000 0.0006 B 56 0.51 30%0.37 42.760 0.777 0.2894 DEVELOPED 0.6600 0.5131 B 56 0.51 10%0.46 1.698 0.031 0.0143 DEVELOPED 0.8200 0.0253 SUM 55.002 SUM 0.3617 0.6415 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.180850829 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00335 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00335 0.18 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.3617 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II (24-(T/60))^1.55 + LAND USE PAVING/HARDSCAPE SF - MEDIUM DENSITY SF - HIGH DENSITY LANDSCAPING PAVING/HARDSCAPE SF - LOW DENSITY LANDSCAPING Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 55.00 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.36 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.36 0.53 0.26 14.44 4,332 4,332 65,450 455 455 3,878 0.09 451.06 2 10 0.17 4.2 0.73 0.36 0.62 0.36 20.19 6,057 9,935 65,955 458 458 9,477 0.22 451.14 3 15 0.25 4.4 0.76 0.36 0.65 0.40 22.11 6,632 16,109 66,511 462 462 15,647 0.36 451.23 4 20 0.33 4.6 0.79 0.36 0.68 0.43 24.02 7,207 22,855 67,119 466 466 22,389 0.51 451.33 5 25 0.42 5.0 0.86 0.36 0.73 0.50 27.86 8,357 30,746 67,830 471 471 30,275 0.70 451.44 6 30 0.50 5.6 0.97 0.36 0.82 0.61 33.61 10,082 40,357 68,695 477 477 39,880 0.92 451.59 7 35 0.58 6.4 1.11 0.36 0.94 0.74 41.27 12,382 52,263 69,768 484 484 51,778 1.19 451.76 8 40 0.67 8.1 1.40 0.36 1.19 1.04 57.57 17,270 69,048 71,275 495 495 68,553 1.57 452.01 9 45 0.75 13.1 2.26 0.36 1.92 1.90 105.48 31,645 100,199 73,913 513 513 99,685 2.29 452.42 10 50 0.83 34.5 5.96 0.36 5.07 5.60 310.57 93,172 192,857 81,521 566 566 192,291 4.41 453.62 11 55 0.92 6.7 1.16 0.36 0.98 0.80 44.15 13,245 205,536 82,535 573 573 204,963 4.71 453.78 12 60 1.00 3.8 0.66 0.36 0.56 0.29 16.36 4,907 209,870 82,881 576 576 209,295 4.80 453.83 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 287,508 cu-ft SOIL LOSSES 72,217 cu-ft EFFECTIVE RAIN 1.08 in FLOOD VOLUME 4.94 acft FLOOD VOLUME 215,291 cu-ft REQUIRED STORAGE 4.80 REQUIRED STORAGE 209,295 cu-ft MAX WSEL 453.83 ft PEAK FLOW RATE 310.57 cfs TOTAL BASIN LOSSES 5,996 cu-ft AVERAGE PERCOLATION RATE 99.94 cf/min CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 55.00 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.36 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.36 0.28 0.05 2.78 833 833 65,135 452 452 381 0.01 451.01 2 10 0.17 1.3 0.33 0.36 0.28 0.05 2.78 833 1,214 65,169 453 453 761 0.02 451.01 3 15 0.25 1.1 0.28 0.36 0.24 0.04 2.35 705 1,466 65,192 453 453 1,014 0.02 451.01 4 20 0.33 1.5 0.39 0.36 0.33 0.02 1.30 391 1,405 65,187 453 453 952 0.02 451.01 5 25 0.42 1.5 0.39 0.36 0.33 0.02 1.30 391 1,343 65,181 453 453 890 0.02 451.01 6 30 0.50 1.8 0.46 0.36 0.39 0.10 5.58 1,673 2,563 65,291 453 453 2,110 0.05 451.03 7 35 0.58 1.5 0.39 0.36 0.33 0.02 1.30 391 2,501 65,285 453 453 2,047 0.05 451.03 8 40 0.67 1.8 0.46 0.36 0.39 0.10 5.58 1,673 3,720 65,395 454 454 3,266 0.07 451.05 9 45 0.75 1.8 0.46 0.36 0.39 0.10 5.58 1,673 4,939 65,505 455 455 4,484 0.10 451.07 10 50 0.83 1.5 0.39 0.36 0.33 0.02 1.30 391 4,875 65,499 455 455 4,420 0.10 451.06 11 55 0.92 1.6 0.41 0.36 0.35 0.05 2.73 818 5,238 65,532 455 455 4,783 0.11 451.07 12 60 1.00 1.8 0.46 0.36 0.39 0.10 5.58 1,673 6,456 65,642 456 456 6,000 0.14 451.09 13 65 1.08 2.2 0.56 0.36 0.48 0.20 11.27 3,382 9,382 65,905 458 458 8,924 0.20 451.13 14 70 1.17 2.2 0.56 0.36 0.48 0.20 11.27 3,382 12,306 66,169 460 460 11,847 0.27 451.17 15 75 1.25 2.2 0.56 0.36 0.48 0.20 11.27 3,382 15,228 66,432 461 461 14,767 0.34 451.22 16 80 1.33 2.0 0.51 0.36 0.44 0.15 8.42 2,527 17,294 66,618 463 463 16,832 0.39 451.25 17 85 1.42 2.6 0.67 0.36 0.57 0.31 16.97 5,091 21,923 67,035 466 466 21,457 0.49 451.32 18 90 1.50 2.7 0.69 0.36 0.59 0.33 18.39 5,518 26,975 67,490 469 469 26,507 0.61 451.39 19 95 1.58 2.4 0.62 0.36 0.52 0.25 14.12 4,236 30,743 67,829 471 471 30,272 0.69 451.44 20 100 1.67 2.7 0.69 0.36 0.59 0.33 18.39 5,518 35,790 68,284 474 474 35,316 0.81 451.52 21 105 1.75 3.3 0.85 0.36 0.72 0.49 26.94 8,082 43,398 68,969 479 479 42,919 0.99 451.63 22 110 1.83 3.1 0.80 0.36 0.68 0.43 24.09 7,227 50,146 69,577 483 483 49,663 1.14 451.73 23 115 1.92 2.9 0.74 0.36 0.63 0.38 21.24 6,373 56,036 70,108 487 487 55,549 1.28 451.82 24 120 2.00 3.0 0.77 0.36 0.65 0.41 22.67 6,800 62,349 70,677 491 491 61,858 1.42 451.91 25 125 2.08 3.1 0.80 0.36 0.68 0.43 24.09 7,227 69,085 71,278 495 495 68,590 1.57 452.01 Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 55.00 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.36 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD 26 130 2.17 4.2 1.08 0.36 0.92 0.72 39.76 11,927 80,517 72,246 502 502 80,016 1.84 452.16 27 135 2.25 5.0 1.28 0.36 1.09 0.92 51.15 15,345 95,361 73,504 510 510 94,851 2.18 452.36 28 140 2.33 3.5 0.90 0.36 0.76 0.54 29.79 8,936 103,787 74,217 515 515 103,272 2.37 452.47 29 145 2.42 6.8 1.75 0.36 1.48 1.38 76.79 23,036 126,308 76,125 529 529 125,779 2.89 452.78 30 150 2.50 7.3 1.87 0.36 1.59 1.51 83.91 25,173 150,952 78,172 543 543 150,409 3.45 453.10 31 155 2.58 8.2 2.11 0.36 1.79 1.74 96.73 29,018 179,427 80,448 559 559 178,868 4.11 453.45 32 160 2.67 5.9 1.52 0.36 1.29 1.15 63.97 19,191 198,059 81,937 569 569 197,490 4.53 453.68 33 165 2.75 2.0 0.51 0.36 0.44 0.15 8.42 2,527 200,017 82,093 570 570 199,447 4.58 453.71 34 170 2.83 1.8 0.46 0.36 0.39 0.10 5.58 1,673 201,120 82,182 571 571 200,549 4.60 453.72 35 175 2.92 1.8 0.46 0.36 0.39 0.10 5.58 1,673 202,222 82,270 571 571 201,651 4.63 453.73 36 180 3.00 0.6 0.15 0.36 0.13 0.02 1.28 385 202,035 82,255 571 571 201,464 4.62 453.73 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 208,194 cu-ft 2.14 in 427,268 cu-ft 453.73 ft 96.73 cfs 17,610 cu-ft 97.83 cf/min 1.10 in 5.03 acft 219,074 cu-ft 4.63 acft 201,651 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 55.00 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.36 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.36 0.14 0.02 1.38 413 413 65,097 452 413 0 0.00 451.00 2 10 0.17 0.6 0.20 0.36 0.17 0.03 1.65 496 496 65,105 452 452 44 0.00 451.00 3 15 0.25 0.6 0.20 0.36 0.17 0.03 1.65 496 540 65,109 452 452 88 0.00 451.00 4 20 0.33 0.6 0.20 0.36 0.17 0.03 1.65 496 584 65,113 452 452 131 0.00 451.00 5 25 0.42 0.6 0.20 0.36 0.17 0.03 1.65 496 627 65,117 452 452 175 0.00 451.00 6 30 0.50 0.7 0.23 0.36 0.20 0.03 1.93 579 754 65,128 452 452 302 0.01 451.00 7 35 0.58 0.7 0.23 0.36 0.20 0.03 1.93 579 880 65,139 452 452 428 0.01 451.01 8 40 0.67 0.7 0.23 0.36 0.20 0.03 1.93 579 1,006 65,151 452 452 554 0.01 451.01 9 45 0.75 0.7 0.23 0.36 0.20 0.03 1.93 579 1,133 65,162 453 453 680 0.02 451.01 10 50 0.83 0.7 0.23 0.36 0.20 0.03 1.93 579 1,259 65,173 453 453 806 0.02 451.01 11 55 0.92 0.7 0.23 0.36 0.20 0.03 1.93 579 1,385 65,185 453 453 932 0.02 451.01 12 60 1.00 0.8 0.26 0.36 0.23 0.04 2.20 661 1,593 65,204 453 453 1,140 0.03 451.02 13 65 1.08 0.8 0.26 0.36 0.23 0.04 2.20 661 1,802 65,222 453 453 1,349 0.03 451.02 14 70 1.17 0.8 0.26 0.36 0.23 0.04 2.20 661 2,010 65,241 453 453 1,557 0.04 451.02 15 75 1.25 0.8 0.26 0.36 0.23 0.04 2.20 661 2,218 65,260 453 453 1,765 0.04 451.03 16 80 1.33 0.8 0.26 0.36 0.23 0.04 2.20 661 2,426 65,279 453 453 1,973 0.05 451.03 17 85 1.42 0.8 0.26 0.36 0.23 0.04 2.20 661 2,634 65,297 453 453 2,181 0.05 451.03 18 90 1.50 0.8 0.26 0.36 0.23 0.04 2.20 661 2,842 65,316 454 454 2,389 0.05 451.04 19 95 1.58 0.8 0.26 0.36 0.23 0.04 2.20 661 3,050 65,335 454 454 2,596 0.06 451.04 20 100 1.67 0.8 0.26 0.36 0.23 0.04 2.20 661 3,257 65,353 454 454 2,803 0.06 451.04 21 105 1.75 0.8 0.26 0.36 0.23 0.04 2.20 661 3,465 65,372 454 454 3,011 0.07 451.04 22 110 1.83 0.8 0.26 0.36 0.23 0.04 2.20 661 3,672 65,391 454 454 3,218 0.07 451.05 23 115 1.92 0.8 0.26 0.36 0.23 0.04 2.20 661 3,879 65,409 454 454 3,425 0.08 451.05 24 120 2.00 0.9 0.30 0.36 0.25 0.04 2.48 744 4,169 65,436 454 454 3,714 0.09 451.05 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 55.00 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.36 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.36 0.23 0.04 2.20 661 4,376 65,454 455 455 3,921 0.09 451.06 26 130 2.17 0.9 0.30 0.36 0.25 0.04 2.48 744 4,665 65,480 455 455 4,210 0.10 451.06 27 135 2.25 0.9 0.30 0.36 0.25 0.04 2.48 744 4,954 65,506 455 455 4,499 0.10 451.07 28 140 2.33 0.9 0.30 0.36 0.25 0.04 2.48 744 5,243 65,532 455 455 4,788 0.11 451.07 29 145 2.42 0.9 0.30 0.36 0.25 0.04 2.48 744 5,532 65,558 455 455 5,077 0.12 451.07 30 150 2.50 0.9 0.30 0.36 0.25 0.04 2.48 744 5,821 65,584 455 455 5,365 0.12 451.08 31 155 2.58 0.9 0.30 0.36 0.25 0.04 2.48 744 6,109 65,610 456 456 5,654 0.13 451.08 32 160 2.67 0.9 0.30 0.36 0.25 0.04 2.48 744 6,398 65,636 456 456 5,942 0.14 451.09 33 165 2.75 1.0 0.33 0.36 0.28 0.05 2.76 827 6,768 65,670 456 456 6,312 0.14 451.09 34 170 2.83 1.0 0.33 0.36 0.28 0.05 2.76 827 7,139 65,703 456 456 6,683 0.15 451.10 35 175 2.92 1.0 0.33 0.36 0.28 0.05 2.76 827 7,509 65,736 457 457 7,053 0.16 451.10 36 180 3.00 1.0 0.33 0.36 0.28 0.05 2.76 827 7,879 65,770 457 457 7,423 0.17 451.11 37 185 3.08 1.0 0.33 0.36 0.28 0.05 2.76 827 8,249 65,803 457 457 7,792 0.18 451.11 38 190 3.17 1.1 0.36 0.36 0.31 0.00 0.15 44 7,836 65,766 457 457 7,379 0.17 451.11 39 195 3.25 1.1 0.36 0.36 0.31 0.00 0.15 44 7,423 65,729 456 456 6,966 0.16 451.10 40 200 3.33 1.1 0.36 0.36 0.31 0.00 0.15 44 7,010 65,691 456 456 6,554 0.15 451.10 41 205 3.42 1.2 0.40 0.36 0.34 0.04 1.98 595 7,148 65,704 456 456 6,692 0.15 451.10 42 210 3.50 1.3 0.43 0.36 0.37 0.07 3.82 1,146 7,838 65,766 457 457 7,381 0.17 451.11 43 215 3.58 1.4 0.46 0.36 0.39 0.10 5.66 1,697 9,078 65,878 457 457 8,620 0.20 451.13 44 220 3.67 1.4 0.46 0.36 0.39 0.10 5.66 1,697 10,317 65,989 458 458 9,859 0.23 451.14 45 225 3.75 1.5 0.50 0.36 0.42 0.14 7.49 2,248 12,106 66,151 459 459 11,647 0.27 451.17 46 230 3.83 1.5 0.50 0.36 0.42 0.14 7.49 2,248 13,895 66,312 460 460 13,434 0.31 451.20 47 235 3.92 1.6 0.53 0.36 0.45 0.17 9.33 2,799 16,233 66,522 462 462 15,771 0.36 451.23 48 240 4.00 1.6 0.53 0.36 0.45 0.17 9.33 2,799 18,570 66,733 463 463 18,107 0.42 451.27 49 245 4.08 1.7 0.56 0.36 0.48 0.20 11.17 3,350 21,457 66,993 465 465 20,991 0.48 451.31 50 250 4.17 1.8 0.60 0.36 0.51 0.23 13.00 3,901 24,892 67,302 467 467 24,425 0.56 451.36 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 55.00 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.36 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.36 0.53 0.27 14.84 4,452 28,877 67,661 470 470 28,407 0.65 451.42 52 260 4.33 2.0 0.66 0.36 0.56 0.30 16.68 5,003 33,410 68,070 473 473 32,937 0.76 451.48 53 265 4.42 2.1 0.70 0.36 0.59 0.33 18.51 5,554 38,492 68,527 476 476 38,016 0.87 451.56 54 270 4.50 2.1 0.70 0.36 0.59 0.33 18.51 5,554 43,570 68,985 479 479 43,091 0.99 451.63 55 275 4.58 2.2 0.73 0.36 0.62 0.37 20.35 6,105 49,196 69,492 483 483 48,713 1.12 451.72 56 280 4.67 2.3 0.76 0.36 0.65 0.40 22.19 6,656 55,370 70,048 486 486 54,883 1.26 451.81 57 285 4.75 2.4 0.79 0.36 0.68 0.43 24.02 7,207 62,090 70,653 491 491 61,600 1.41 451.90 58 290 4.83 2.4 0.79 0.36 0.68 0.43 24.02 7,207 68,807 71,255 495 495 68,312 1.57 452.00 59 295 4.92 2.5 0.83 0.36 0.70 0.47 25.86 7,758 76,071 71,870 499 499 75,571 1.73 452.10 60 300 5.00 2.6 0.86 0.36 0.73 0.50 27.70 8,309 83,881 72,531 504 504 83,377 1.91 452.21 61 305 5.08 3.1 1.03 0.36 0.87 0.67 36.88 11,065 94,442 73,426 510 510 93,932 2.16 452.35 62 310 5.17 3.6 1.19 0.36 1.01 0.83 46.07 13,820 107,752 74,553 518 518 107,234 2.46 452.53 63 315 5.25 3.9 1.29 0.36 1.10 0.93 51.58 15,473 122,707 75,820 527 527 122,181 2.80 452.73 64 320 5.33 4.2 1.39 0.36 1.18 1.03 57.09 17,126 139,307 77,226 536 536 138,771 3.19 452.95 65 325 5.42 4.7 1.56 0.36 1.32 1.19 66.27 19,882 158,652 78,787 547 547 158,105 3.63 453.19 66 330 5.50 5.6 1.85 0.36 1.58 1.49 82.80 24,841 182,946 80,729 561 561 182,386 4.19 453.50 67 335 5.58 1.9 0.63 0.36 0.53 0.27 14.84 4,452 186,838 81,040 563 563 186,275 4.28 453.54 68 340 5.67 0.9 0.30 0.36 0.25 0.04 2.48 744 187,019 81,055 563 563 186,456 4.28 453.55 69 345 5.75 0.6 0.20 0.36 0.17 0.03 1.65 496 186,952 81,049 563 563 186,389 4.28 453.54 70 350 5.83 0.5 0.17 0.36 0.14 0.02 1.38 413 186,802 81,037 563 563 186,240 4.28 453.54 71 355 5.92 0.3 0.10 0.36 0.08 0.01 0.83 248 186,488 81,012 563 563 185,925 4.27 453.54 72 360 6.00 0.2 0.07 0.36 0.06 0.01 0.55 165 186,090 80,980 562 562 185,528 4.26 453.53 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 551,056 cu-ft 2.76 in 331,366 cu-ft 453.55 ft 82.80 cfs 94.90 cf/min 34,162 cu-ft 1.10 in 5.04 acft 219,690 cu-ft 4.28 acft 186,456 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 55.00 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.18 LAG TIME - MINUTES 3.99 C 0.00335 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.639 0.030 0.01 0.29 264 264 65,084 1,356 264 0 0.00 451.00 2 30 0.50 0.3 0.053 0.631 0.045 0.01 0.44 396 396 65,096 1,356 396 0 0.00 451.00 3 45 0.75 0.3 0.053 0.624 0.045 0.01 0.44 396 396 65,096 1,356 396 0 0.00 451.00 4 60 1.00 0.4 0.071 0.617 0.060 0.01 0.59 528 528 65,108 1,356 528 0 0.00 451.00 5 75 1.25 0.3 0.053 0.609 0.045 0.01 0.44 396 396 65,096 1,356 396 0 0.00 451.00 6 90 1.50 0.3 0.053 0.602 0.045 0.01 0.44 396 396 65,096 1,356 396 0 0.00 451.00 7 105 1.75 0.3 0.053 0.595 0.045 0.01 0.44 396 396 65,096 1,356 396 0 0.00 451.00 8 120 2.00 0.4 0.071 0.588 0.060 0.01 0.59 528 528 65,108 1,356 528 0 0.00 451.00 9 135 2.25 0.4 0.071 0.581 0.060 0.01 0.59 528 528 65,108 1,356 528 0 0.00 451.00 10 150 2.50 0.4 0.071 0.574 0.060 0.01 0.59 528 528 65,108 1,356 528 0 0.00 451.00 11 165 2.75 0.5 0.088 0.567 0.075 0.01 0.73 660 660 65,119 1,357 660 0 0.00 451.00 12 180 3.00 0.5 0.088 0.560 0.075 0.01 0.73 660 660 65,119 1,357 660 0 0.00 451.00 13 195 3.25 0.5 0.088 0.553 0.075 0.01 0.73 660 660 65,119 1,357 660 0 0.00 451.00 14 210 3.50 0.5 0.088 0.546 0.075 0.01 0.73 660 660 65,119 1,357 660 0 0.00 451.00 15 225 3.75 0.5 0.088 0.539 0.075 0.01 0.73 660 660 65,119 1,357 660 0 0.00 451.00 16 240 4.00 0.6 0.106 0.532 0.090 0.02 0.88 792 792 65,131 1,357 792 0 0.00 451.00 17 255 4.25 0.6 0.106 0.525 0.090 0.02 0.88 792 792 65,131 1,357 792 0 0.00 451.00 18 270 4.50 0.7 0.123 0.519 0.105 0.02 1.03 925 925 65,143 1,357 925 0 0.00 451.00 19 285 4.75 0.7 0.123 0.512 0.105 0.02 1.03 925 925 65,143 1,357 925 0 0.00 451.00 20 300 5.00 0.8 0.141 0.505 0.120 0.02 1.17 1,057 1,057 65,155 1,357 1,057 0 0.00 451.00 21 315 5.25 0.6 0.106 0.499 0.090 0.02 0.88 792 792 65,131 1,357 792 0 0.00 451.00 22 330 5.50 0.7 0.123 0.492 0.105 0.02 1.03 925 925 65,143 1,357 925 0 0.00 451.00 23 345 5.75 0.8 0.141 0.486 0.120 0.02 1.17 1,057 1,057 65,155 1,357 1,057 0 0.00 451.00 24 360 6.00 0.8 0.141 0.480 0.120 0.02 1.17 1,057 1,057 65,155 1,357 1,057 0 0.00 451.00 25 375 6.25 0.9 0.159 0.473 0.135 0.02 1.32 1,189 1,189 65,167 1,358 1,189 0 0.00 451.00 26 390 6.50 0.9 0.159 0.467 0.135 0.02 1.32 1,189 1,189 65,167 1,358 1,189 0 0.00 451.00 27 405 6.75 1.0 0.176 0.461 0.150 0.03 1.47 1,321 1,321 65,179 1,358 1,321 0 0.00 451.00 28 420 7.00 1.0 0.176 0.454 0.150 0.03 1.47 1,321 1,321 65,179 1,358 1,321 0 0.00 451.00 29 435 7.25 1.0 0.176 0.448 0.150 0.03 1.47 1,321 1,321 65,179 1,358 1,321 0 0.00 451.00 30 450 7.50 1.1 0.194 0.442 0.165 0.03 1.61 1,453 1,453 65,191 1,358 1,358 95 0.00 451.00 31 465 7.75 1.2 0.212 0.436 0.180 0.03 1.76 1,585 1,680 65,211 1,359 1,359 321 0.01 451.00 32 480 8.00 1.3 0.229 0.430 0.195 0.03 1.91 1,717 2,038 65,244 1,359 1,359 679 0.02 451.01 33 495 8.25 1.5 0.265 0.424 0.225 0.04 2.20 1,981 2,660 65,300 1,360 1,360 1,299 0.03 451.02 34 510 8.50 1.5 0.265 0.418 0.225 0.04 2.20 1,981 3,281 65,356 1,362 1,362 1,919 0.04 451.03 35 525 8.75 1.6 0.282 0.412 0.240 0.04 2.35 2,113 4,032 65,423 1,363 1,363 2,669 0.06 451.04 36 540 9.00 1.7 0.300 0.407 0.255 0.04 2.49 2,245 4,914 65,503 1,365 1,365 3,550 0.08 451.05 37 555 9.25 1.9 0.335 0.401 0.285 0.05 2.79 2,509 6,059 65,606 1,367 1,367 4,692 0.11 451.07 38 570 9.50 2.0 0.353 0.395 0.300 0.05 2.93 2,641 7,334 65,721 1,369 1,369 5,965 0.14 451.09 39 585 9.75 2.1 0.370 0.389 0.315 0.06 3.08 2,774 8,738 65,847 1,372 1,372 7,366 0.17 451.11 40 600 10.00 2.2 0.388 0.384 0.330 0.00 0.24 213 7,580 65,743 1,370 1,370 6,210 0.14 451.09 41 615 10.25 1.5 0.265 0.378 0.225 0.04 2.20 1,981 8,191 65,798 1,371 1,371 6,820 0.16 451.10 42 630 10.50 1.5 0.265 0.373 0.225 0.04 2.20 1,981 8,801 65,853 1,372 1,372 7,429 0.17 451.11 43 645 10.75 2.0 0.353 0.367 0.300 0.05 2.93 2,641 10,071 65,967 1,374 1,374 8,697 0.20 451.13 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 55.00 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.18 LAG TIME - MINUTES 3.99 C 0.00335 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 44 660 11.00 2.0 0.353 0.362 0.300 0.05 2.93 2,641 11,338 66,081 1,377 1,377 9,961 0.23 451.15 45 675 11.25 1.9 0.335 0.357 0.285 0.05 2.79 2,509 12,471 66,183 1,379 1,379 11,092 0.25 451.16 46 690 11.50 1.9 0.335 0.351 0.285 0.05 2.79 2,509 13,601 66,285 1,381 1,381 12,220 0.28 451.18 47 705 11.75 1.7 0.300 0.346 0.255 0.04 2.49 2,245 14,466 66,363 1,383 1,383 13,083 0.30 451.19 48 720 12.00 1.8 0.318 0.341 0.270 0.05 2.64 2,377 15,460 66,453 1,384 1,384 14,076 0.32 451.21 49 735 12.25 2.5 0.441 0.336 0.375 0.11 5.83 5,244 19,319 66,800 1,392 1,392 17,928 0.41 451.26 50 750 12.50 2.6 0.459 0.331 0.390 0.13 7.08 6,375 24,303 67,249 1,401 1,401 22,902 0.53 451.34 51 765 12.75 2.8 0.494 0.326 0.420 0.17 9.32 8,384 31,286 67,878 1,414 1,414 29,872 0.69 451.44 52 780 13.00 2.9 0.512 0.321 0.435 0.19 10.57 9,510 39,382 68,608 1,429 1,429 37,953 0.87 451.56 53 795 13.25 3.4 0.600 0.316 0.510 0.28 15.73 14,155 52,108 69,754 1,453 1,453 50,654 1.16 451.74 54 810 13.50 3.4 0.600 0.311 0.510 0.29 15.99 14,394 65,048 70,920 1,477 1,477 63,571 1.46 451.93 55 825 13.75 2.3 0.406 0.307 0.345 0.10 5.49 4,945 68,515 71,230 1,484 1,484 67,032 1.54 451.98 56 840 14.00 2.3 0.406 0.302 0.345 0.10 5.75 5,178 72,209 71,543 1,490 1,490 70,719 1.62 452.04 57 855 14.25 2.7 0.476 0.297 0.405 0.18 9.92 8,929 79,648 72,173 1,504 1,504 78,144 1.79 452.14 58 870 14.50 2.6 0.459 0.293 0.390 0.17 9.20 8,276 86,420 72,746 1,516 1,516 84,904 1.95 452.23 59 885 14.75 2.6 0.459 0.288 0.390 0.17 9.44 8,499 93,403 73,338 1,528 1,528 91,876 2.11 452.32 60 900 15.00 2.5 0.441 0.284 0.375 0.16 8.71 7,839 99,714 73,872 1,539 1,539 98,175 2.25 452.40 61 915 15.25 2.4 0.423 0.280 0.360 0.14 7.97 7,175 105,350 74,350 1,549 1,549 103,801 2.38 452.48 62 930 15.50 2.3 0.406 0.275 0.345 0.13 7.23 6,508 110,309 74,770 1,558 1,558 108,752 2.50 452.55 63 945 15.75 1.9 0.335 0.271 0.285 0.06 3.55 3,196 111,948 74,909 1,561 1,561 110,388 2.53 452.57 64 960 16.00 1.9 0.335 0.267 0.285 0.07 3.78 3,403 113,791 75,065 1,564 1,564 112,227 2.58 452.59 65 975 16.25 0.4 0.071 0.263 0.060 0.01 0.59 528 112,755 74,977 1,562 1,562 111,193 2.55 452.58 66 990 16.50 0.4 0.071 0.259 0.060 0.01 0.59 528 111,721 74,889 1,560 1,560 110,161 2.53 452.57 67 1005 16.75 0.3 0.053 0.255 0.045 0.01 0.44 396 110,557 74,791 1,558 1,558 108,999 2.50 452.55 68 1020 17.00 0.3 0.053 0.251 0.045 0.01 0.44 396 109,396 74,692 1,556 1,556 107,839 2.48 452.53 69 1035 17.25 0.5 0.088 0.247 0.075 0.01 0.73 660 108,500 74,617 1,555 1,555 106,945 2.46 452.52 70 1050 17.50 0.5 0.088 0.244 0.075 0.01 0.73 660 107,606 74,541 1,553 1,553 106,053 2.43 452.51 71 1065 17.75 0.5 0.088 0.240 0.075 0.01 0.73 660 106,713 74,465 1,551 1,551 105,162 2.41 452.50 72 1080 18.00 0.4 0.071 0.236 0.060 0.01 0.59 528 105,690 74,379 1,550 1,550 104,141 2.39 452.48 73 1095 18.25 0.4 0.071 0.233 0.060 0.01 0.59 528 104,669 74,292 1,548 1,548 103,121 2.37 452.47 74 1110 18.50 0.4 0.071 0.230 0.060 0.01 0.59 528 103,649 74,206 1,546 1,546 102,103 2.34 452.46 75 1125 18.75 0.3 0.053 0.226 0.045 0.01 0.44 396 102,500 74,108 1,544 1,544 100,956 2.32 452.44 76 1140 19.00 0.2 0.035 0.223 0.030 0.01 0.29 264 101,220 74,000 1,542 1,542 99,678 2.29 452.42 77 1155 19.25 0.3 0.053 0.220 0.045 0.01 0.44 396 100,074 73,903 1,540 1,540 98,535 2.26 452.41 78 1170 19.50 0.4 0.071 0.217 0.060 0.01 0.59 528 99,063 73,817 1,538 1,538 97,525 2.24 452.40 79 1185 19.75 0.3 0.053 0.214 0.045 0.01 0.44 396 97,921 73,721 1,536 1,536 96,386 2.21 452.38 80 1200 20.00 0.2 0.035 0.211 0.030 0.01 0.29 264 96,650 73,613 1,534 1,534 95,116 2.18 452.36 81 1215 20.25 0.3 0.053 0.208 0.045 0.01 0.44 396 95,512 73,516 1,532 1,532 93,981 2.16 452.35 82 1230 20.50 0.3 0.053 0.206 0.045 0.01 0.44 396 94,377 73,420 1,530 1,530 92,847 2.13 452.33 83 1245 20.75 0.3 0.053 0.203 0.045 0.01 0.44 396 93,244 73,324 1,528 1,528 91,716 2.11 452.32 84 1260 21.00 0.2 0.035 0.200 0.030 0.01 0.29 264 91,980 73,217 1,525 1,525 90,455 2.08 452.30 85 1275 21.25 0.3 0.053 0.198 0.045 0.01 0.44 396 90,851 73,122 1,523 1,523 89,328 2.05 452.29 86 1290 21.50 0.2 0.035 0.196 0.030 0.01 0.29 264 89,592 73,015 1,521 1,521 88,071 2.02 452.27 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 55.00 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.18 LAG TIME - MINUTES 3.99 C 0.00335 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 87 1305 21.75 0.3 0.053 0.194 0.045 0.01 0.44 396 88,467 72,920 1,519 1,519 86,948 2.00 452.25 88 1320 22.00 0.2 0.035 0.192 0.030 0.01 0.29 264 87,212 72,813 1,517 1,517 85,695 1.97 452.24 89 1335 22.25 0.3 0.053 0.190 0.045 0.01 0.44 396 86,091 72,718 1,515 1,515 84,576 1.94 452.22 90 1350 22.50 0.2 0.035 0.188 0.030 0.01 0.29 264 84,840 72,613 1,513 1,513 83,328 1.91 452.20 91 1365 22.75 0.2 0.035 0.186 0.030 0.01 0.29 264 83,592 72,507 1,511 1,511 82,081 1.88 452.19 92 1380 23.00 0.2 0.035 0.185 0.030 0.01 0.29 264 82,345 72,401 1,508 1,508 80,837 1.86 452.17 93 1395 23.25 0.2 0.035 0.184 0.030 0.01 0.29 264 81,101 72,296 1,506 1,506 79,595 1.83 452.15 94 1410 23.50 0.2 0.035 0.182 0.030 0.01 0.29 264 79,859 72,191 1,504 1,504 78,355 1.80 452.14 95 1425 23.75 0.2 0.035 0.182 0.030 0.01 0.29 264 78,619 72,086 1,502 1,502 77,117 1.77 452.12 96 1440 24.00 0.2 0.035 0.181 0.030 0.01 0.29 264 77,382 71,981 1,500 1,500 75,882 1.74 452.10 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 4.41 in 880,492 cu-ft 683,384 cu-ft 452.59 ft 15.99 cfs 121,226 cu-ft 84.18 cf/min 0.99 in 4.52 acft 197,108 cu-ft 2.58 acft 112,227 cu-ft Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 451 0 0 65,060 0 0 0.00 452 1 1 6,135 71,195 68,104 68,104 1.56 453 1 2 6,295 77,490 74,320 142,425 3.27 454 1 3 6,450 83,940 80,694 223,118 5.12 WHERE: TOTAL BASIN F BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 2 B PAVING/HARDSCAPE 2.588 D 56 0.51 1.00 3 B WATER FEATURE 2.323 D 56 0.51 1.00 1 B COMMERCIAL 4.803 D 56 0.51 0.90 6 B SF - HIGH DENSITY 7.637 D 56 0.51 0.50 9 B LANDSCAPING 11.052 D 56 0.51 0.10 780 ft 390 ft 459.5 ft ELEVATION OF CONCENTRATION POINT 453.0 ft 0.02 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 451.0 ft 101,190 sf 452.0 ft 112,495 sf 452.5 ft 135,570 sf PERCOLATION RATE (in/hr)0.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-D RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 BASIN D AMC NUMBER Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)148,469 220,641 284,565 454,686 SOIL LOSSES (cu-ft)28,994 85,691 152,510 322,600 EFFECTIVE RAIN (in)1.16 1.31 1.28 1.28 FLOOD VOLUME (cu-ft)119,475 134,950 132,055 132,086 (acre-ft)2.74 3.10 3.03 3.03 REQUIRED STORAGE (cu-ft)119,475 134,950 132,055 132,086 (acre-ft)2.74 3.10 3.03 3.03 FACTOR OF SAFETY 1.41 1.25 1.28 1.28 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 52.25 45.06 10.24 MAXIMUM WSEL (ft)452.10 452.23 452.20 452.20 DEPTH (ft)1.10 1.23 1.20 1.20 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days) [18] 200% OF LAG-MINUTES RAINFALL DATA 5.0 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 168,719 3.87 0.02 [17] 100% OF LAG-MINUTES 2.5 2.5 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.04 [16] LAG TIME-MINUTES [13] L*LCA/S^0.5 6.63 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.002 390.00 [12] S^0.5 0.074 44.0 459.5 453 6.5 [3] AREA - ACRES [4] L-FEET [5] L-MILES 780 0.148 BASIN D DA-D CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 28.403 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 100%0.05 2.588 0.091 0.0046 DEVELOPED 0.1000 0.0091 B 56 0.51 100%0.05 2.323 0.082 0.0042 DEVELOPED 0.1000 0.0082 B 56 0.51 90%0.10 4.803 0.169 0.0164 DEVELOPED 0.1800 0.0304 B 56 0.51 50%0.28 7.637 0.269 0.0754 DEVELOPED 0.5000 0.1344 B 56 0.51 10%0.46 11.052 0.389 0.1806 DEVELOPED 0.8200 0.3191 SUM 28.403 SUM 0.2812 0.5012 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.140606334 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00260 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00260 0.14 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.2812 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. LANDSCAPING (24-(T/60))^1.55 + LAND USE PAVING/HARDSCAPE WATER FEATURE COMMERCIAL SF - HIGH DENSITY AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 28.40 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.52 Maxwell Drywells UNIT TIME-PERCENT OF LAG 198.4 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.28 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.28 0.53 0.34 9.76 2,929 2,929 101,500 0 0 2,929 0.07 451.03 2 10 0.17 4.2 0.73 0.28 0.62 0.44 12.73 3,820 6,748 101,904 0 0 6,748 0.15 451.06 3 15 0.25 4.4 0.76 0.28 0.65 0.48 13.72 4,116 10,865 102,340 0 0 10,865 0.25 451.10 4 20 0.33 4.6 0.79 0.28 0.68 0.51 14.71 4,413 15,278 102,807 0 0 15,278 0.35 451.14 5 25 0.42 5.0 0.86 0.28 0.73 0.58 16.69 5,007 20,285 103,337 0 0 20,285 0.47 451.19 6 30 0.50 5.6 0.97 0.28 0.82 0.69 19.66 5,898 26,183 103,962 0 0 26,183 0.60 451.25 7 35 0.58 6.4 1.11 0.28 0.94 0.82 23.62 7,086 33,269 104,712 0 0 33,269 0.76 451.31 8 40 0.67 8.1 1.40 0.28 1.19 1.12 32.03 9,610 42,879 105,729 0 0 42,879 0.98 451.40 9 45 0.75 13.1 2.26 0.28 1.92 1.98 56.78 17,033 59,912 107,532 0 0 59,912 1.38 451.56 10 50 0.83 34.5 5.96 0.28 5.07 5.68 162.69 48,806 108,718 113,212 0 0 108,718 2.50 452.02 11 55 0.92 6.7 1.16 0.28 0.98 0.88 25.10 7,531 116,249 116,019 0 0 116,249 2.67 452.08 12 60 1.00 3.8 0.66 0.28 0.56 0.38 10.75 3,226 119,475 117,221 0 0 119,475 2.74 452.10 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 148,469 cu-ft SOIL LOSSES 28,994 cu-ft EFFECTIVE RAIN 1.16 in FLOOD VOLUME 2.74 acft FLOOD VOLUME 119,475 cu-ft REQUIRED STORAGE 2.74 REQUIRED STORAGE 119,475 cu-ft MAX WSEL 452.10 ft PEAK FLOW RATE 162.69 cfs TOTAL BASIN LOSSES 0 cu-ft AVERAGE PERCOLATION RATE 0.00 cf/min EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 28.40 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.52 Maxwell Drywells UNIT TIME-PERCENT OF LAG 198.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.28 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.28 0.28 0.05 1.51 452 452 101,238 0 0 452 0.01 451.00 2 10 0.17 1.3 0.33 0.28 0.28 0.05 1.51 452 904 101,286 0 0 904 0.02 451.01 3 15 0.25 1.1 0.28 0.28 0.24 0.00 0.04 11 915 101,287 0 0 915 0.02 451.01 4 20 0.33 1.5 0.39 0.28 0.33 0.10 2.98 893 1,809 101,381 0 0 1,809 0.04 451.02 5 25 0.42 1.5 0.39 0.28 0.33 0.10 2.98 893 2,702 101,476 0 0 2,702 0.06 451.03 6 30 0.50 1.8 0.46 0.28 0.39 0.18 5.18 1,555 4,258 101,641 0 0 4,258 0.10 451.04 7 35 0.58 1.5 0.39 0.28 0.33 0.10 2.98 893 5,151 101,735 0 0 5,151 0.12 451.05 8 40 0.67 1.8 0.46 0.28 0.39 0.18 5.18 1,555 6,706 101,900 0 0 6,706 0.15 451.06 9 45 0.75 1.8 0.46 0.28 0.39 0.18 5.18 1,555 8,262 102,065 0 0 8,262 0.19 451.08 10 50 0.83 1.5 0.39 0.28 0.33 0.10 2.98 893 9,155 102,159 0 0 9,155 0.21 451.09 11 55 0.92 1.6 0.41 0.28 0.35 0.13 3.71 1,114 10,269 102,277 0 0 10,269 0.24 451.10 12 60 1.00 1.8 0.46 0.28 0.39 0.18 5.18 1,555 11,825 102,442 0 0 11,825 0.27 451.11 13 65 1.08 2.2 0.56 0.28 0.48 0.28 8.13 2,438 14,263 102,700 0 0 14,263 0.33 451.13 14 70 1.17 2.2 0.56 0.28 0.48 0.28 8.13 2,438 16,701 102,958 0 0 16,701 0.38 451.16 15 75 1.25 2.2 0.56 0.28 0.48 0.28 8.13 2,438 19,138 103,216 0 0 19,138 0.44 451.18 16 80 1.33 2.0 0.51 0.28 0.44 0.23 6.66 1,997 21,135 103,427 0 0 21,135 0.49 451.20 17 85 1.42 2.6 0.67 0.28 0.57 0.39 11.07 3,321 24,456 103,779 0 0 24,456 0.56 451.23 18 90 1.50 2.7 0.69 0.28 0.59 0.41 11.80 3,541 27,997 104,154 0 0 27,997 0.64 451.26 19 95 1.58 2.4 0.62 0.28 0.52 0.34 9.60 2,879 30,876 104,459 0 0 30,876 0.71 451.29 20 100 1.67 2.7 0.69 0.28 0.59 0.41 11.80 3,541 34,417 104,833 0 0 34,417 0.79 451.32 21 105 1.75 3.3 0.85 0.28 0.72 0.57 16.22 4,865 39,282 105,348 0 0 39,282 0.90 451.37 22 110 1.83 3.1 0.80 0.28 0.68 0.51 14.75 4,424 43,706 105,817 0 0 43,706 1.00 451.41 23 115 1.92 2.9 0.74 0.28 0.63 0.46 13.27 3,982 47,688 106,238 0 0 47,688 1.09 451.45 24 120 2.00 3.0 0.77 0.28 0.65 0.49 14.01 4,203 51,891 106,683 0 0 51,891 1.19 451.49 25 125 2.08 3.1 0.80 0.28 0.68 0.51 14.75 4,424 56,315 107,151 0 0 56,315 1.29 451.53 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 28.40 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.52 Maxwell Drywells UNIT TIME-PERCENT OF LAG 198.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.28 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses 26 130 2.17 4.2 1.08 0.28 0.92 0.80 22.84 6,851 63,166 107,877 0 0 63,166 1.45 451.59 27 135 2.25 5.0 1.28 0.28 1.09 1.00 28.72 8,616 71,782 108,789 0 0 71,782 1.65 451.67 28 140 2.33 3.5 0.90 0.28 0.76 0.62 17.69 5,306 77,088 109,350 0 0 77,088 1.77 451.72 29 145 2.42 6.8 1.75 0.28 1.48 1.47 41.96 12,587 89,675 110,683 0 0 89,675 2.06 451.84 30 150 2.50 7.3 1.87 0.28 1.59 1.59 45.64 13,691 103,366 112,132 0 0 103,366 2.37 451.97 31 155 2.58 8.2 2.11 0.28 1.79 1.82 52.25 15,676 119,042 117,060 0 0 119,042 2.73 452.10 32 160 2.67 5.9 1.52 0.28 1.29 1.23 35.34 10,602 129,644 121,010 0 0 129,644 2.98 452.18 33 165 2.75 2.0 0.51 0.28 0.44 0.23 6.66 1,997 131,641 121,754 0 0 131,641 3.02 452.20 34 170 2.83 1.8 0.46 0.28 0.39 0.18 5.18 1,555 133,196 122,333 0 0 133,196 3.06 452.21 35 175 2.92 1.8 0.46 0.28 0.39 0.18 5.18 1,555 134,752 122,913 0 0 134,752 3.09 452.23 36 180 3.00 0.6 0.15 0.28 0.13 0.02 0.66 199 134,950 122,987 0 0 134,950 3.10 452.23 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY 0 cu-ft 0.00 cf/min 1.31 in 3.10 acft 134,950 cu-ft 3.10 acft 134,950 cu-ft 85,691 cu-ft 2.14 in 220,641 cu-ft 452.23 ft 52.25 cfs Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 28.40 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.52 Maxwell Drywells UNIT TIME-PERCENT OF LAG 198.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.28 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.28 0.14 0.02 0.71 213 213 101,213 0 0 213 0.00 451.00 2 10 0.17 0.6 0.20 0.28 0.17 0.03 0.85 256 470 101,240 0 0 470 0.01 451.00 3 15 0.25 0.6 0.20 0.28 0.17 0.03 0.85 256 726 101,267 0 0 726 0.02 451.01 4 20 0.33 0.6 0.20 0.28 0.17 0.03 0.85 256 982 101,294 0 0 982 0.02 451.01 5 25 0.42 0.6 0.20 0.28 0.17 0.03 0.85 256 1,238 101,321 0 0 1,238 0.03 451.01 6 30 0.50 0.7 0.23 0.28 0.20 0.03 1.00 299 1,537 101,353 0 0 1,537 0.04 451.01 7 35 0.58 0.7 0.23 0.28 0.20 0.03 1.00 299 1,835 101,384 0 0 1,835 0.04 451.02 8 40 0.67 0.7 0.23 0.28 0.20 0.03 1.00 299 2,134 101,416 0 0 2,134 0.05 451.02 9 45 0.75 0.7 0.23 0.28 0.20 0.03 1.00 299 2,433 101,448 0 0 2,433 0.06 451.02 10 50 0.83 0.7 0.23 0.28 0.20 0.03 1.00 299 2,732 101,479 0 0 2,732 0.06 451.03 11 55 0.92 0.7 0.23 0.28 0.20 0.03 1.00 299 3,031 101,511 0 0 3,031 0.07 451.03 12 60 1.00 0.8 0.26 0.28 0.23 0.04 1.14 341 3,372 101,547 0 0 3,372 0.08 451.03 13 65 1.08 0.8 0.26 0.28 0.23 0.04 1.14 341 3,714 101,583 0 0 3,714 0.09 451.03 14 70 1.17 0.8 0.26 0.28 0.23 0.04 1.14 341 4,055 101,619 0 0 4,055 0.09 451.04 15 75 1.25 0.8 0.26 0.28 0.23 0.04 1.14 341 4,397 101,655 0 0 4,397 0.10 451.04 16 80 1.33 0.8 0.26 0.28 0.23 0.04 1.14 341 4,738 101,692 0 0 4,738 0.11 451.04 17 85 1.42 0.8 0.26 0.28 0.23 0.04 1.14 341 5,079 101,728 0 0 5,079 0.12 451.05 18 90 1.50 0.8 0.26 0.28 0.23 0.04 1.14 341 5,421 101,764 0 0 5,421 0.12 451.05 19 95 1.58 0.8 0.26 0.28 0.23 0.04 1.14 341 5,762 101,800 0 0 5,762 0.13 451.05 20 100 1.67 0.8 0.26 0.28 0.23 0.04 1.14 341 6,104 101,836 0 0 6,104 0.14 451.06 21 105 1.75 0.8 0.26 0.28 0.23 0.04 1.14 341 6,445 101,872 0 0 6,445 0.15 451.06 22 110 1.83 0.8 0.26 0.28 0.23 0.04 1.14 341 6,787 101,908 0 0 6,787 0.16 451.06 23 115 1.92 0.8 0.26 0.28 0.23 0.04 1.14 341 7,128 101,945 0 0 7,128 0.16 451.07 24 120 2.00 0.9 0.30 0.28 0.25 0.02 0.48 145 7,273 101,960 0 0 7,273 0.17 451.07 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 28.40 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.52 Maxwell Drywells UNIT TIME-PERCENT OF LAG 198.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.28 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.28 0.23 0.04 1.14 341 7,615 101,996 0 0 7,615 0.17 451.07 26 130 2.17 0.9 0.30 0.28 0.25 0.02 0.48 145 7,760 102,011 0 0 7,760 0.18 451.07 27 135 2.25 0.9 0.30 0.28 0.25 0.02 0.48 145 7,905 102,027 0 0 7,905 0.18 451.07 28 140 2.33 0.9 0.30 0.28 0.25 0.02 0.48 145 8,050 102,042 0 0 8,050 0.18 451.08 29 145 2.42 0.9 0.30 0.28 0.25 0.02 0.48 145 8,194 102,057 0 0 8,194 0.19 451.08 30 150 2.50 0.9 0.30 0.28 0.25 0.02 0.48 145 8,339 102,073 0 0 8,339 0.19 451.08 31 155 2.58 0.9 0.30 0.28 0.25 0.02 0.48 145 8,484 102,088 0 0 8,484 0.19 451.08 32 160 2.67 0.9 0.30 0.28 0.25 0.02 0.48 145 8,629 102,103 0 0 8,629 0.20 451.08 33 165 2.75 1.0 0.33 0.28 0.28 0.05 1.43 429 9,059 102,149 0 0 9,059 0.21 451.08 34 170 2.83 1.0 0.33 0.28 0.28 0.05 1.43 429 9,488 102,194 0 0 9,488 0.22 451.09 35 175 2.92 1.0 0.33 0.28 0.28 0.05 1.43 429 9,918 102,240 0 0 9,918 0.23 451.09 36 180 3.00 1.0 0.33 0.28 0.28 0.05 1.43 429 10,347 102,285 0 0 10,347 0.24 451.10 37 185 3.08 1.0 0.33 0.28 0.28 0.05 1.43 429 10,777 102,331 0 0 10,777 0.25 451.10 38 190 3.17 1.1 0.36 0.28 0.31 0.08 2.38 714 11,491 102,406 0 0 11,491 0.26 451.11 39 195 3.25 1.1 0.36 0.28 0.31 0.08 2.38 714 12,205 102,482 0 0 12,205 0.28 451.11 40 200 3.33 1.1 0.36 0.28 0.31 0.08 2.38 714 12,919 102,558 0 0 12,919 0.30 451.12 41 205 3.42 1.2 0.40 0.28 0.34 0.12 3.33 999 13,917 102,663 0 0 13,917 0.32 451.13 42 210 3.50 1.3 0.43 0.28 0.37 0.15 4.28 1,283 15,201 102,799 0 0 15,201 0.35 451.14 43 215 3.58 1.4 0.46 0.28 0.39 0.18 5.23 1,568 16,768 102,965 0 0 16,768 0.38 451.16 44 220 3.67 1.4 0.46 0.28 0.39 0.18 5.23 1,568 18,336 103,131 0 0 18,336 0.42 451.17 45 225 3.75 1.5 0.50 0.28 0.42 0.22 6.17 1,852 20,188 103,327 0 0 20,188 0.46 451.19 46 230 3.83 1.5 0.50 0.28 0.42 0.22 6.17 1,852 22,041 103,523 0 0 22,041 0.51 451.21 47 235 3.92 1.6 0.53 0.28 0.45 0.25 7.12 2,137 24,178 103,749 0 0 24,178 0.56 451.23 48 240 4.00 1.6 0.53 0.28 0.45 0.25 7.12 2,137 26,315 103,976 0 0 26,315 0.60 451.25 49 245 4.08 1.7 0.56 0.28 0.48 0.28 8.07 2,421 28,736 104,232 0 0 28,736 0.66 451.27 50 250 4.17 1.8 0.60 0.28 0.51 0.31 9.02 2,706 31,442 104,518 0 0 31,442 0.72 451.29 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 28.40 Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 2.52 Maxwell Drywells UNIT TIME-PERCENT OF LAG 198.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.28 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.28 0.53 0.35 9.97 2,991 34,433 104,835 0 0 34,433 0.79 451.32 52 260 4.33 2.0 0.66 0.28 0.56 0.38 10.92 3,275 37,708 105,182 0 0 37,708 0.87 451.35 53 265 4.42 2.1 0.70 0.28 0.59 0.41 11.87 3,560 41,267 105,559 0 0 41,267 0.95 451.39 54 270 4.50 2.1 0.70 0.28 0.59 0.41 11.87 3,560 44,827 105,935 0 0 44,827 1.03 451.42 55 275 4.58 2.2 0.73 0.28 0.62 0.45 12.81 3,844 48,671 106,342 0 0 48,671 1.12 451.46 56 280 4.67 2.3 0.76 0.28 0.65 0.48 13.76 4,129 52,800 106,779 0 0 52,800 1.21 451.49 57 285 4.75 2.4 0.79 0.28 0.68 0.51 14.71 4,413 57,214 107,247 0 0 57,214 1.31 451.54 58 290 4.83 2.4 0.79 0.28 0.68 0.51 14.71 4,413 61,627 107,714 0 0 61,627 1.41 451.58 59 295 4.92 2.5 0.83 0.28 0.70 0.55 15.66 4,698 66,325 108,211 0 0 66,325 1.52 451.62 60 300 5.00 2.6 0.86 0.28 0.73 0.58 16.61 4,983 71,307 108,739 0 0 71,307 1.64 451.67 61 305 5.08 3.1 1.03 0.28 0.87 0.75 21.35 6,405 77,713 109,417 0 0 77,713 1.78 451.73 62 310 5.17 3.6 1.19 0.28 1.01 0.91 26.09 7,828 85,541 110,245 0 0 85,541 1.96 451.80 63 315 5.25 3.9 1.29 0.28 1.10 1.01 28.94 8,682 94,223 111,164 0 0 94,223 2.16 451.88 64 320 5.33 4.2 1.39 0.28 1.18 1.11 31.79 9,536 103,758 112,174 0 0 103,758 2.38 451.97 65 325 5.42 4.7 1.56 0.28 1.32 1.28 36.53 10,958 114,717 115,448 0 0 114,717 2.63 452.06 66 330 5.50 5.6 1.85 0.28 1.58 1.57 45.06 13,519 128,236 120,485 0 0 128,236 2.94 452.17 67 335 5.58 1.9 0.63 0.28 0.53 0.35 9.97 2,991 131,227 121,600 0 0 131,227 3.01 452.20 68 340 5.67 0.9 0.30 0.28 0.25 0.02 0.48 145 131,372 121,654 0 0 131,372 3.02 452.20 69 345 5.75 0.6 0.20 0.28 0.17 0.03 0.85 256 131,628 121,749 0 0 131,628 3.02 452.20 70 350 5.83 0.5 0.17 0.28 0.14 0.02 0.71 213 131,841 121,829 0 0 131,841 3.03 452.20 71 355 5.92 0.3 0.10 0.28 0.08 0.01 0.43 128 131,969 121,876 0 0 131,969 3.03 452.20 72 360 6.00 0.2 0.07 0.28 0.06 0.01 0.28 85 132,055 121,908 0 0 132,055 3.03 452.20 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY 0.00 cf/min 0 cu-ft 1.28 in 3.03 acft 132,055 cu-ft 3.03 acft 132,055 cu-ft 284,565 cu-ft 2.76 in 152,510 cu-ft 452.20 ft 45.06 cfs Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 28.40 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.14 LAG TIME - MINUTES 2.52 C 0.00260 Maxwell Drywells UNIT TIME-PERCENT OF LAG 595%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.497 0.030 0.01 0.15 136 136 101,204 0 0 136 0.00 451.00 2 30 0.50 0.3 0.053 0.491 0.045 0.01 0.23 205 341 101,226 0 0 341 0.01 451.00 3 45 0.75 0.3 0.053 0.485 0.045 0.01 0.23 205 546 101,248 0 0 546 0.01 451.01 4 60 1.00 0.4 0.071 0.479 0.060 0.01 0.30 273 818 101,277 0 0 818 0.02 451.01 5 75 1.25 0.3 0.053 0.474 0.045 0.01 0.23 205 1,023 101,298 0 0 1,023 0.02 451.01 6 90 1.50 0.3 0.053 0.468 0.045 0.01 0.23 205 1,228 101,320 0 0 1,228 0.03 451.01 7 105 1.75 0.3 0.053 0.463 0.045 0.01 0.23 205 1,432 101,342 0 0 1,432 0.03 451.01 8 120 2.00 0.4 0.071 0.457 0.060 0.01 0.30 273 1,705 101,370 0 0 1,705 0.04 451.02 9 135 2.25 0.4 0.071 0.451 0.060 0.01 0.30 273 1,978 101,399 0 0 1,978 0.05 451.02 10 150 2.50 0.4 0.071 0.446 0.060 0.01 0.30 273 2,251 101,428 0 0 2,251 0.05 451.02 11 165 2.75 0.5 0.088 0.440 0.075 0.01 0.38 341 2,592 101,464 0 0 2,592 0.06 451.02 12 180 3.00 0.5 0.088 0.435 0.075 0.01 0.38 341 2,933 101,500 0 0 2,933 0.07 451.03 13 195 3.25 0.5 0.088 0.430 0.075 0.01 0.38 341 3,274 101,537 0 0 3,274 0.08 451.03 14 210 3.50 0.5 0.088 0.424 0.075 0.01 0.38 341 3,615 101,573 0 0 3,615 0.08 451.03 15 225 3.75 0.5 0.088 0.419 0.075 0.01 0.38 341 3,956 101,609 0 0 3,956 0.09 451.04 16 240 4.00 0.6 0.106 0.414 0.090 0.02 0.45 409 4,365 101,652 0 0 4,365 0.10 451.04 17 255 4.25 0.6 0.106 0.409 0.090 0.02 0.45 409 4,774 101,695 0 0 4,774 0.11 451.04 18 270 4.50 0.7 0.123 0.403 0.105 0.02 0.53 477 5,252 101,746 0 0 5,252 0.12 451.05 19 285 4.75 0.7 0.123 0.398 0.105 0.02 0.53 477 5,729 101,796 0 0 5,729 0.13 451.05 20 300 5.00 0.8 0.141 0.393 0.120 0.02 0.61 546 6,275 101,854 0 0 6,275 0.14 451.06 21 315 5.25 0.6 0.106 0.388 0.090 0.02 0.45 409 6,684 101,898 0 0 6,684 0.15 451.06 22 330 5.50 0.7 0.123 0.383 0.105 0.02 0.53 477 7,161 101,948 0 0 7,161 0.16 451.07 23 345 5.75 0.8 0.141 0.378 0.120 0.02 0.61 546 7,707 102,006 0 0 7,707 0.18 451.07 24 360 6.00 0.8 0.141 0.373 0.120 0.02 0.61 546 8,253 102,064 0 0 8,253 0.19 451.08 25 375 6.25 0.9 0.159 0.368 0.135 0.02 0.68 614 8,866 102,129 0 0 8,866 0.20 451.08 26 390 6.50 0.9 0.159 0.363 0.135 0.02 0.68 614 9,480 102,194 0 0 9,480 0.22 451.09 27 405 6.75 1.0 0.176 0.358 0.150 0.03 0.76 682 10,162 102,266 0 0 10,162 0.23 451.10 28 420 7.00 1.0 0.176 0.353 0.150 0.03 0.76 682 10,844 102,338 0 0 10,844 0.25 451.10 29 435 7.25 1.0 0.176 0.348 0.150 0.03 0.76 682 11,526 102,410 0 0 11,526 0.26 451.11 30 450 7.50 1.1 0.194 0.344 0.165 0.03 0.83 750 12,277 102,490 0 0 12,277 0.28 451.11 31 465 7.75 1.2 0.212 0.339 0.180 0.03 0.91 818 13,095 102,576 0 0 13,095 0.30 451.12 32 480 8.00 1.3 0.229 0.334 0.195 0.03 0.99 887 13,982 102,670 0 0 13,982 0.32 451.13 33 495 8.25 1.5 0.265 0.330 0.225 0.04 1.14 1,023 15,005 102,778 0 0 15,005 0.34 451.14 34 510 8.50 1.5 0.265 0.325 0.225 0.04 1.14 1,023 16,028 102,887 0 0 16,028 0.37 451.15 35 525 8.75 1.6 0.282 0.321 0.240 0.04 1.21 1,091 17,119 103,002 0 0 17,119 0.39 451.16 36 540 9.00 1.7 0.300 0.316 0.255 0.04 1.29 1,159 18,278 103,125 0 0 18,278 0.42 451.17 37 555 9.25 1.9 0.335 0.312 0.285 0.02 0.68 608 18,886 103,189 0 0 18,886 0.43 451.18 38 570 9.50 2.0 0.353 0.307 0.300 0.05 1.31 1,177 20,063 103,314 0 0 20,063 0.46 451.19 39 585 9.75 2.1 0.370 0.303 0.315 0.07 1.94 1,745 21,808 103,499 0 0 21,808 0.50 451.20 40 600 10.00 2.2 0.388 0.298 0.330 0.09 2.57 2,312 24,119 103,743 0 0 24,119 0.55 451.23 41 615 10.25 1.5 0.265 0.294 0.225 0.04 1.14 1,023 25,142 103,852 0 0 25,142 0.58 451.24 42 630 10.50 1.5 0.265 0.290 0.225 0.04 1.14 1,023 26,165 103,960 0 0 26,165 0.60 451.25 43 645 10.75 2.0 0.353 0.286 0.300 0.07 1.92 1,732 27,897 104,143 0 0 27,897 0.64 451.26 in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 28.40 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.14 LAG TIME - MINUTES 2.52 C 0.00260 Maxwell Drywells UNIT TIME-PERCENT OF LAG 595%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses 44 660 11.00 2.0 0.353 0.281 0.300 0.07 2.04 1,840 29,737 104,338 0 0 29,737 0.68 451.28 45 675 11.25 1.9 0.335 0.277 0.285 0.06 1.66 1,492 31,229 104,496 0 0 31,229 0.72 451.29 46 690 11.50 1.9 0.335 0.273 0.285 0.06 1.77 1,597 32,826 104,665 0 0 32,826 0.75 451.31 47 705 11.75 1.7 0.300 0.269 0.255 0.03 0.88 792 33,618 104,749 0 0 33,618 0.77 451.31 48 720 12.00 1.8 0.318 0.265 0.270 0.05 1.50 1,350 34,968 104,892 0 0 34,968 0.80 451.33 49 735 12.25 2.5 0.441 0.261 0.375 0.18 5.15 4,635 39,603 105,382 0 0 39,603 0.91 451.37 50 750 12.50 2.6 0.459 0.257 0.390 0.20 5.77 5,190 44,793 105,932 0 0 44,793 1.03 451.42 51 765 12.75 2.8 0.494 0.253 0.420 0.24 6.89 6,199 50,992 106,588 0 0 50,992 1.17 451.48 52 780 13.00 2.9 0.512 0.250 0.435 0.26 7.50 6,752 57,744 107,303 0 0 57,744 1.33 451.54 53 795 13.25 3.4 0.600 0.246 0.510 0.35 10.14 9,123 66,868 108,269 0 0 66,868 1.54 451.63 54 810 13.50 3.4 0.600 0.242 0.510 0.36 10.24 9,219 76,087 109,244 0 0 76,087 1.75 451.71 55 825 13.75 2.3 0.406 0.238 0.345 0.17 4.79 4,312 80,399 109,701 0 0 80,399 1.85 451.75 56 840 14.00 2.3 0.406 0.235 0.345 0.17 4.90 4,406 84,805 110,167 0 0 84,805 1.95 451.79 57 855 14.25 2.7 0.476 0.231 0.405 0.25 7.02 6,317 91,122 110,836 0 0 91,122 2.09 451.85 58 870 14.50 2.6 0.459 0.228 0.390 0.23 6.61 5,953 97,075 111,466 0 0 97,075 2.23 451.91 59 885 14.75 2.6 0.459 0.224 0.390 0.23 6.71 6,043 103,118 112,106 0 0 103,118 2.37 451.97 60 900 15.00 2.5 0.441 0.221 0.375 0.22 6.31 5,677 108,794 113,241 0 0 108,794 2.50 452.02 61 915 15.25 2.4 0.423 0.217 0.360 0.21 5.90 5,309 114,103 115,219 0 0 114,103 2.62 452.06 62 930 15.50 2.3 0.406 0.214 0.345 0.19 5.49 4,940 119,044 117,060 0 0 119,044 2.73 452.10 63 945 15.75 1.9 0.335 0.211 0.285 0.12 3.56 3,206 122,249 118,254 0 0 122,249 2.81 452.12 64 960 16.00 1.9 0.335 0.208 0.285 0.13 3.65 3,289 125,538 119,480 0 0 125,538 2.88 452.15 65 975 16.25 0.4 0.071 0.204 0.060 0.01 0.30 273 125,811 119,582 0 0 125,811 2.89 452.15 66 990 16.50 0.4 0.071 0.201 0.060 0.01 0.30 273 126,084 119,683 0 0 126,084 2.89 452.16 67 1005 16.75 0.3 0.053 0.198 0.045 0.01 0.23 205 126,288 119,759 0 0 126,288 2.90 452.16 68 1020 17.00 0.3 0.053 0.195 0.045 0.01 0.23 205 126,493 119,836 0 0 126,493 2.90 452.16 69 1035 17.25 0.5 0.088 0.192 0.075 0.01 0.38 341 126,834 119,963 0 0 126,834 2.91 452.16 70 1050 17.50 0.5 0.088 0.189 0.075 0.01 0.38 341 127,175 120,090 0 0 127,175 2.92 452.16 71 1065 17.75 0.5 0.088 0.187 0.075 0.01 0.38 341 127,516 120,217 0 0 127,516 2.93 452.17 72 1080 18.00 0.4 0.071 0.184 0.060 0.01 0.30 273 127,789 120,319 0 0 127,789 2.93 452.17 73 1095 18.25 0.4 0.071 0.181 0.060 0.01 0.30 273 128,062 120,420 0 0 128,062 2.94 452.17 74 1110 18.50 0.4 0.071 0.178 0.060 0.01 0.30 273 128,334 120,522 0 0 128,334 2.95 452.17 75 1125 18.75 0.3 0.053 0.176 0.045 0.01 0.23 205 128,539 120,598 0 0 128,539 2.95 452.18 76 1140 19.00 0.2 0.035 0.173 0.030 0.01 0.15 136 128,675 120,649 0 0 128,675 2.95 452.18 77 1155 19.25 0.3 0.053 0.171 0.045 0.01 0.23 205 128,880 120,725 0 0 128,880 2.96 452.18 78 1170 19.50 0.4 0.071 0.169 0.060 0.01 0.30 273 129,153 120,827 0 0 129,153 2.96 452.18 79 1185 19.75 0.3 0.053 0.166 0.045 0.01 0.23 205 129,357 120,903 0 0 129,357 2.97 452.18 80 1200 20.00 0.2 0.035 0.164 0.030 0.01 0.15 136 129,494 120,954 0 0 129,494 2.97 452.18 81 1215 20.25 0.3 0.053 0.162 0.045 0.01 0.23 205 129,698 121,030 0 0 129,698 2.98 452.18 82 1230 20.50 0.3 0.053 0.160 0.045 0.01 0.23 205 129,903 121,106 0 0 129,903 2.98 452.19 83 1245 20.75 0.3 0.053 0.158 0.045 0.01 0.23 205 130,108 121,183 0 0 130,108 2.99 452.19 84 1260 21.00 0.2 0.035 0.156 0.030 0.01 0.15 136 130,244 121,233 0 0 130,244 2.99 452.19 85 1275 21.25 0.3 0.053 0.154 0.045 0.01 0.23 205 130,449 121,310 0 0 130,449 2.99 452.19 86 1290 21.50 0.2 0.035 0.152 0.030 0.01 0.15 136 130,585 121,361 0 0 130,585 3.00 452.19 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 28.40 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 0.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.14 LAG TIME - MINUTES 2.52 C 0.00260 Maxwell Drywells UNIT TIME-PERCENT OF LAG 595%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses 87 1305 21.75 0.3 0.053 0.151 0.045 0.01 0.23 205 130,790 121,437 0 0 130,790 3.00 452.19 88 1320 22.00 0.2 0.035 0.149 0.030 0.01 0.15 136 130,926 121,488 0 0 130,926 3.01 452.19 89 1335 22.25 0.3 0.053 0.148 0.045 0.01 0.23 205 131,131 121,564 0 0 131,131 3.01 452.20 90 1350 22.50 0.2 0.035 0.146 0.030 0.01 0.15 136 131,267 121,615 0 0 131,267 3.01 452.20 91 1365 22.75 0.2 0.035 0.145 0.030 0.01 0.15 136 131,403 121,665 0 0 131,403 3.02 452.20 92 1380 23.00 0.2 0.035 0.144 0.030 0.01 0.15 136 131,540 121,716 0 0 131,540 3.02 452.20 93 1395 23.25 0.2 0.035 0.143 0.030 0.01 0.15 136 131,676 121,767 0 0 131,676 3.02 452.20 94 1410 23.50 0.2 0.035 0.142 0.030 0.01 0.15 136 131,813 121,818 0 0 131,813 3.03 452.20 95 1425 23.75 0.2 0.035 0.141 0.030 0.01 0.15 136 131,949 121,869 0 0 131,949 3.03 452.20 96 1440 24.00 0.2 0.035 0.141 0.030 0.01 0.15 136 132,086 121,920 0 0 132,086 3.03 452.20 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 0 cu-ft 0.00 cf/min 1.28 in 3.03 acft 132,086 cu-ft 3.03 acft 132,086 cu-ft 4.41 in 454,686 cu-ft 322,600 cu-ft 452.20 ft 10.24 cfs Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 451 0 0 101,190 0 0 0.00 452 1 1 11,305 112,495 106,793 106,793 2.45 452.5 0.5 1.5 23,075 135,570 61,927 168,719 3.87 WHERE: TOTAL BASIN D BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 2 B PAVING/HARDSCAPE 1.707 D 56 0.51 1.00 4 B SF - LOW DENSITY 48.170 D 56 0.51 0.30 6 B SF - HIGH DENSITY 4.271 D 56 0.51 0.50 9 B LANDSCAPING 7.654 D 56 0.51 0.10 1,560 ft 780 ft 490.0 ft ELEVATION OF CONCENTRATION POINT 455.0 ft 0.02 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 442.0 ft 224,555 sf 443.0 ft 231,980 sf 444.0 ft 239,460 sf 445.0 ft 247,000 sf 446.0 ft 254,595 sf 447.0 ft 262,250 sf PERCOLATION RATE (in/hr)1.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 BASIN E AMC NUMBER RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-E Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)323,053 480,092 619,184 989,349 SOIL LOSSES (cu-ft)82,659 237,971 372,822 769,875 EFFECTIVE RAIN (in)1.07 1.08 1.10 0.98 FLOOD VOLUME (cu-ft)240,394 242,121 246,363 219,473 (acre-ft)5.52 5.56 5.66 5.04 REQUIRED STORAGE (cu-ft)221,456 193,888 172,408 59,359 (acre-ft)5.08 4.45 3.96 1.36 FACTOR OF SAFETY 5.49 6.27 7.06 20.49 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 108.26 92.62 17.61 MAXIMUM WSEL (ft)442.97 442.85 442.76 442.26 DEPTH (ft)0.97 0.85 0.76 0.26 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days)0.5 0.6 0.8 1.0 BASIN E DA-E CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 61.802 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION [3] AREA - ACRES [4] L-FEET [5] L-MILES 1560 0.295 [13] L*LCA/S^0.5 10.88 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.004 780.00 [12] S^0.5 0.148 118.5 490 455 35 0.02 [17] 100% OF LAG-MINUTES 3.5 3.5 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.06 [16] LAG TIME-MINUTES [18] 200% OF LAG-MINUTES RAINFALL DATA 7.1 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 1,216,389 27.92 Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 100%0.05 1.707 0.028 0.0014 DEVELOPED 0.1000 0.0028 B 56 0.51 30%0.37 48.170 0.779 0.2902 DEVELOPED 0.6600 0.5144 B 56 0.51 50%0.28 4.271 0.069 0.0194 DEVELOPED 0.5000 0.0346 B 56 0.51 10%0.46 7.654 0.124 0.0575 DEVELOPED 0.8200 0.1016 SUM 61.802 SUM 0.3685 0.6533 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.184225307 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00341 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00341 0.18 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.3685 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II (24-(T/60))^1.55 + LAND USE PAVING/HARDSCAPE SF - LOW DENSITY SF - HIGH DENSITY LANDSCAPING Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 61.80 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.54 Maxwell Drywells UNIT TIME-PERCENT OF LAG 141.4 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.37 0.53 0.25 15.81 4,742 4,742 224,709 1,560 1,560 3,181 0.07 442.01 2 10 0.17 4.2 0.73 0.37 0.62 0.36 22.27 6,680 9,861 224,876 1,562 1,562 8,299 0.19 442.04 3 15 0.25 4.4 0.76 0.37 0.65 0.39 24.42 7,326 15,626 225,063 1,563 1,563 14,063 0.32 442.06 4 20 0.33 4.6 0.79 0.37 0.68 0.43 26.57 7,972 22,035 225,272 1,564 1,564 20,470 0.47 442.09 5 25 0.42 5.0 0.86 0.37 0.73 0.50 30.88 9,264 29,735 225,522 1,566 1,566 28,169 0.65 442.12 6 30 0.50 5.6 0.97 0.37 0.82 0.60 37.34 11,203 39,371 225,836 1,568 1,568 37,803 0.87 442.17 7 35 0.58 6.4 1.11 0.37 0.94 0.74 45.96 13,787 51,590 226,233 1,571 1,571 50,019 1.15 442.22 8 40 0.67 8.1 1.40 0.37 1.19 1.03 64.26 19,279 69,298 226,809 1,575 1,575 67,723 1.55 442.30 9 45 0.75 13.1 2.26 0.37 1.92 1.90 118.11 35,432 103,155 227,911 1,583 1,583 101,572 2.33 442.44 10 50 0.83 34.5 5.96 0.37 5.07 5.59 348.55 104,565 206,137 231,260 1,606 1,606 204,531 4.70 442.90 11 55 0.92 6.7 1.16 0.37 0.98 0.79 49.19 14,756 219,287 231,688 1,609 1,609 217,678 5.00 442.95 12 60 1.00 3.8 0.66 0.37 0.56 0.29 17.96 5,388 223,066 231,811 1,610 1,610 221,456 5.08 442.97 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 323,053 cu-ft SOIL LOSSES 82,659 cu-ft EFFECTIVE RAIN 1.07 in FLOOD VOLUME 5.52 acft FLOOD VOLUME 240,394 cu-ft REQUIRED STORAGE 5.08 REQUIRED STORAGE 221,456 cu-ft MAX WSEL 442.97 ft PEAK FLOW RATE 348.55 cfs TOTAL BASIN LOSSES 18,937 cu-ft AVERAGE PERCOLATION RATE 315.62 cf/min CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 61.80 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.54 Maxwell Drywells UNIT TIME-PERCENT OF LAG 141.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.37 0.28 0.05 3.12 936 936 224,585 1,560 936 0 0.00 442.00 2 10 0.17 1.3 0.33 0.37 0.28 0.05 3.12 936 936 224,585 1,560 936 0 0.00 442.00 3 15 0.25 1.1 0.28 0.37 0.24 0.04 2.64 792 792 224,581 1,560 792 0 0.00 442.00 4 20 0.33 1.5 0.39 0.37 0.33 0.02 1.04 313 313 224,565 1,559 313 0 0.00 442.00 5 25 0.42 1.5 0.39 0.37 0.33 0.02 1.04 313 313 224,565 1,559 313 0 0.00 442.00 6 30 0.50 1.8 0.46 0.37 0.39 0.09 5.84 1,753 1,753 224,612 1,560 1,560 194 0.00 442.00 7 35 0.58 1.5 0.39 0.37 0.33 0.02 1.04 313 507 224,571 1,560 507 0 0.00 442.00 8 40 0.67 1.8 0.46 0.37 0.39 0.09 5.84 1,753 1,753 224,612 1,560 1,560 194 0.00 442.00 9 45 0.75 1.8 0.46 0.37 0.39 0.09 5.84 1,753 1,947 224,618 1,560 1,560 387 0.01 442.00 10 50 0.83 1.5 0.39 0.37 0.33 0.02 1.04 313 700 224,578 1,560 700 0 0.00 442.00 11 55 0.92 1.6 0.41 0.37 0.35 0.04 2.64 793 793 224,581 1,560 793 0 0.00 442.00 12 60 1.00 1.8 0.46 0.37 0.39 0.09 5.84 1,753 1,753 224,612 1,560 1,560 194 0.00 442.00 13 65 1.08 2.2 0.56 0.37 0.48 0.20 12.25 3,674 3,867 224,681 1,560 1,560 2,307 0.05 442.01 14 70 1.17 2.2 0.56 0.37 0.48 0.20 12.25 3,674 5,981 224,750 1,561 1,561 4,420 0.10 442.02 15 75 1.25 2.2 0.56 0.37 0.48 0.20 12.25 3,674 8,094 224,818 1,561 1,561 6,533 0.15 442.03 16 80 1.33 2.0 0.51 0.37 0.44 0.15 9.05 2,714 9,246 224,856 1,561 1,561 7,685 0.18 442.03 17 85 1.42 2.6 0.67 0.37 0.57 0.30 18.65 5,594 13,279 224,987 1,562 1,562 11,716 0.27 442.05 18 90 1.50 2.7 0.69 0.37 0.59 0.32 20.25 6,074 17,791 225,134 1,563 1,563 16,227 0.37 442.07 19 95 1.58 2.4 0.62 0.37 0.52 0.25 15.45 4,634 20,861 225,234 1,564 1,564 19,297 0.44 442.08 20 100 1.67 2.7 0.69 0.37 0.59 0.32 20.25 6,074 25,371 225,380 1,565 1,565 23,806 0.55 442.10 21 105 1.75 3.3 0.85 0.37 0.72 0.48 29.85 8,955 32,761 225,621 1,567 1,567 31,194 0.72 442.14 22 110 1.83 3.1 0.80 0.37 0.68 0.43 26.65 7,995 39,189 225,830 1,568 1,568 37,621 0.86 442.16 23 115 1.92 2.9 0.74 0.37 0.63 0.38 23.45 7,034 44,655 226,008 1,569 1,569 43,085 0.99 442.19 24 120 2.00 3.0 0.77 0.37 0.65 0.40 25.05 7,515 50,600 226,201 1,571 1,571 49,029 1.13 442.21 25 125 2.08 3.1 0.80 0.37 0.68 0.43 26.65 7,995 57,024 226,410 1,572 1,572 55,451 1.27 442.24 Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 61.80 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.54 Maxwell Drywells UNIT TIME-PERCENT OF LAG 141.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD 26 130 2.17 4.2 1.08 0.37 0.92 0.71 44.25 13,276 68,727 226,791 1,575 1,575 67,152 1.54 442.29 27 135 2.25 5.0 1.28 0.37 1.09 0.92 57.05 17,116 84,269 227,296 1,578 1,578 82,690 1.90 442.36 28 140 2.33 3.5 0.90 0.37 0.76 0.53 33.05 9,915 92,605 227,567 1,580 1,580 91,025 2.09 442.40 29 145 2.42 6.8 1.75 0.37 1.48 1.38 85.86 25,758 116,783 228,354 1,586 1,586 115,197 2.64 442.50 30 150 2.50 7.3 1.87 0.37 1.59 1.51 93.86 28,158 143,355 229,218 1,592 1,592 141,764 3.25 442.62 31 155 2.58 8.2 2.11 0.37 1.79 1.74 108.26 32,479 174,243 230,223 1,599 1,599 172,644 3.96 442.76 32 160 2.67 5.9 1.52 0.37 1.29 1.15 71.46 21,437 194,081 230,868 1,603 1,603 192,478 4.42 442.84 33 165 2.75 2.0 0.51 0.37 0.44 0.15 9.05 2,714 195,192 230,904 1,604 1,604 193,588 4.44 442.85 34 170 2.83 1.8 0.46 0.37 0.39 0.09 5.84 1,753 195,342 230,909 1,604 1,604 193,738 4.45 442.85 35 175 2.92 1.8 0.46 0.37 0.39 0.09 5.84 1,753 195,491 230,914 1,604 1,604 193,888 4.45 442.85 36 180 3.00 0.6 0.15 0.37 0.13 0.02 1.44 432 194,320 230,876 1,603 1,603 192,717 4.42 442.84 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 237,971 cu-ft 2.14 in 480,092 cu-ft 442.85 ft 108.26 cfs 49,404 cu-ft 274.47 cf/min 1.08 in 5.56 acft 242,121 cu-ft 4.45 acft 193,888 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 61.80 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.54 Maxwell Drywells UNIT TIME-PERCENT OF LAG 141.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.37 0.14 0.02 1.55 464 464 224,570 1,560 464 0 0.00 442.00 2 10 0.17 0.6 0.20 0.37 0.17 0.03 1.86 557 557 224,573 1,560 557 0 0.00 442.00 3 15 0.25 0.6 0.20 0.37 0.17 0.03 1.86 557 557 224,573 1,560 557 0 0.00 442.00 4 20 0.33 0.6 0.20 0.37 0.17 0.03 1.86 557 557 224,573 1,560 557 0 0.00 442.00 5 25 0.42 0.6 0.20 0.37 0.17 0.03 1.86 557 557 224,573 1,560 557 0 0.00 442.00 6 30 0.50 0.7 0.23 0.37 0.20 0.03 2.17 650 650 224,576 1,560 650 0 0.00 442.00 7 35 0.58 0.7 0.23 0.37 0.20 0.03 2.17 650 650 224,576 1,560 650 0 0.00 442.00 8 40 0.67 0.7 0.23 0.37 0.20 0.03 2.17 650 650 224,576 1,560 650 0 0.00 442.00 9 45 0.75 0.7 0.23 0.37 0.20 0.03 2.17 650 650 224,576 1,560 650 0 0.00 442.00 10 50 0.83 0.7 0.23 0.37 0.20 0.03 2.17 650 650 224,576 1,560 650 0 0.00 442.00 11 55 0.92 0.7 0.23 0.37 0.20 0.03 2.17 650 650 224,576 1,560 650 0 0.00 442.00 12 60 1.00 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 13 65 1.08 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 14 70 1.17 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 15 75 1.25 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 16 80 1.33 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 17 85 1.42 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 18 90 1.50 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 19 95 1.58 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 20 100 1.67 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 21 105 1.75 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 22 110 1.83 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 23 115 1.92 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 24 120 2.00 0.9 0.30 0.37 0.25 0.04 2.79 836 836 224,582 1,560 836 0 0.00 442.00 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 61.80 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.54 Maxwell Drywells UNIT TIME-PERCENT OF LAG 141.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.37 0.23 0.04 2.48 743 743 224,579 1,560 743 0 0.00 442.00 26 130 2.17 0.9 0.30 0.37 0.25 0.04 2.79 836 836 224,582 1,560 836 0 0.00 442.00 27 135 2.25 0.9 0.30 0.37 0.25 0.04 2.79 836 836 224,582 1,560 836 0 0.00 442.00 28 140 2.33 0.9 0.30 0.37 0.25 0.04 2.79 836 836 224,582 1,560 836 0 0.00 442.00 29 145 2.42 0.9 0.30 0.37 0.25 0.04 2.79 836 836 224,582 1,560 836 0 0.00 442.00 30 150 2.50 0.9 0.30 0.37 0.25 0.04 2.79 836 836 224,582 1,560 836 0 0.00 442.00 31 155 2.58 0.9 0.30 0.37 0.25 0.04 2.79 836 836 224,582 1,560 836 0 0.00 442.00 32 160 2.67 0.9 0.30 0.37 0.25 0.04 2.79 836 836 224,582 1,560 836 0 0.00 442.00 33 165 2.75 1.0 0.33 0.37 0.28 0.05 3.10 929 929 224,585 1,560 929 0 0.00 442.00 34 170 2.83 1.0 0.33 0.37 0.28 0.05 3.10 929 929 224,585 1,560 929 0 0.00 442.00 35 175 2.92 1.0 0.33 0.37 0.28 0.05 3.10 929 929 224,585 1,560 929 0 0.00 442.00 36 180 3.00 1.0 0.33 0.37 0.28 0.05 3.10 929 929 224,585 1,560 929 0 0.00 442.00 37 185 3.08 1.0 0.33 0.37 0.28 0.05 3.10 929 929 224,585 1,560 929 0 0.00 442.00 38 190 3.17 1.1 0.36 0.37 0.31 0.05 3.41 1,022 1,022 224,588 1,560 1,022 0 0.00 442.00 39 195 3.25 1.1 0.36 0.37 0.31 0.05 3.41 1,022 1,022 224,588 1,560 1,022 0 0.00 442.00 40 200 3.33 1.1 0.36 0.37 0.31 0.05 3.41 1,022 1,022 224,588 1,560 1,022 0 0.00 442.00 41 205 3.42 1.2 0.40 0.37 0.34 0.03 1.81 542 542 224,573 1,560 542 0 0.00 442.00 42 210 3.50 1.3 0.43 0.37 0.37 0.06 3.87 1,161 1,161 224,593 1,560 1,161 0 0.00 442.00 43 215 3.58 1.4 0.46 0.37 0.39 0.10 5.93 1,780 1,780 224,613 1,560 1,560 221 0.01 442.00 44 220 3.67 1.4 0.46 0.37 0.39 0.10 5.93 1,780 2,001 224,620 1,560 1,560 441 0.01 442.00 45 225 3.75 1.5 0.50 0.37 0.42 0.13 8.00 2,400 2,841 224,647 1,560 1,560 1,280 0.03 442.01 46 230 3.83 1.5 0.50 0.37 0.42 0.13 8.00 2,400 3,680 224,675 1,560 1,560 2,120 0.05 442.01 47 235 3.92 1.6 0.53 0.37 0.45 0.16 10.06 3,019 5,138 224,722 1,561 1,561 3,578 0.08 442.02 48 240 4.00 1.6 0.53 0.37 0.45 0.16 10.06 3,019 6,597 224,770 1,561 1,561 5,036 0.12 442.02 49 245 4.08 1.7 0.56 0.37 0.48 0.19 12.13 3,638 8,674 224,837 1,561 1,561 7,112 0.16 442.03 50 250 4.17 1.8 0.60 0.37 0.51 0.23 14.19 4,257 11,369 224,925 1,562 1,562 9,807 0.23 442.04 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 61.80 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.54 Maxwell Drywells UNIT TIME-PERCENT OF LAG 141.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.37 0.53 0.26 16.25 4,876 14,684 225,033 1,563 1,563 13,121 0.30 442.06 52 260 4.33 2.0 0.66 0.37 0.56 0.29 18.32 5,495 18,616 225,161 1,564 1,564 17,053 0.39 442.07 53 265 4.42 2.1 0.70 0.37 0.59 0.33 20.38 6,115 23,167 225,309 1,565 1,565 21,603 0.50 442.09 54 270 4.50 2.1 0.70 0.37 0.59 0.33 20.38 6,115 27,717 225,457 1,566 1,566 26,152 0.60 442.11 55 275 4.58 2.2 0.73 0.37 0.62 0.36 22.45 6,734 32,885 225,625 1,567 1,567 31,318 0.72 442.14 56 280 4.67 2.3 0.76 0.37 0.65 0.39 24.51 7,353 38,671 225,813 1,568 1,568 37,103 0.85 442.16 57 285 4.75 2.4 0.79 0.37 0.68 0.43 26.57 7,972 45,076 226,021 1,570 1,570 43,506 1.00 442.19 58 290 4.83 2.4 0.79 0.37 0.68 0.43 26.57 7,972 51,478 226,230 1,571 1,571 49,907 1.15 442.22 59 295 4.92 2.5 0.83 0.37 0.70 0.46 28.64 8,591 58,498 226,458 1,573 1,573 56,926 1.31 442.25 60 300 5.00 2.6 0.86 0.37 0.73 0.49 30.70 9,211 66,136 226,706 1,574 1,574 64,562 1.48 442.28 61 305 5.08 3.1 1.03 0.37 0.87 0.66 41.02 12,306 76,868 227,055 1,577 1,577 75,292 1.73 442.33 62 310 5.17 3.6 1.19 0.37 1.01 0.82 51.34 15,402 90,694 227,505 1,580 1,580 89,114 2.05 442.39 63 315 5.25 3.9 1.29 0.37 1.10 0.92 57.53 17,260 106,374 228,015 1,583 1,583 104,791 2.41 442.46 64 320 5.33 4.2 1.39 0.37 1.18 1.02 63.72 19,117 123,908 228,586 1,587 1,587 122,321 2.81 442.54 65 325 5.42 4.7 1.56 0.37 1.32 1.19 74.04 22,213 144,534 229,257 1,592 1,592 142,942 3.28 442.63 66 330 5.50 5.6 1.85 0.37 1.58 1.49 92.62 27,786 170,728 230,109 1,598 1,598 169,130 3.88 442.74 67 335 5.58 1.9 0.63 0.37 0.53 0.26 16.25 4,876 174,006 230,215 1,599 1,599 172,408 3.96 442.76 68 340 5.67 0.9 0.30 0.37 0.25 0.04 2.79 836 173,244 230,190 1,599 1,599 171,645 3.94 442.75 69 345 5.75 0.6 0.20 0.37 0.17 0.03 1.86 557 172,202 230,157 1,598 1,598 170,604 3.92 442.75 70 350 5.83 0.5 0.17 0.37 0.14 0.02 1.55 464 171,068 230,120 1,598 1,598 169,470 3.89 442.74 71 355 5.92 0.3 0.10 0.37 0.08 0.01 0.93 279 169,749 230,077 1,598 1,598 168,151 3.86 442.74 72 360 6.00 0.2 0.07 0.37 0.06 0.01 0.62 186 168,337 230,031 1,597 1,597 166,740 3.83 442.73 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 619,184 cu-ft 2.76 in 372,822 cu-ft 442.76 ft 92.62 cfs 221.18 cf/min 79,623 cu-ft 1.10 in 5.66 acft 246,363 cu-ft 3.96 acft 172,408 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 61.80 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.18 LAG TIME - MINUTES 3.54 C 0.00341 Maxwell Drywells UNIT TIME-PERCENT OF LAG 424%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.651 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 2 30 0.50 0.3 0.053 0.643 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 3 45 0.75 0.3 0.053 0.636 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 4 60 1.00 0.4 0.071 0.628 0.060 0.01 0.66 594 594 224,574 4,679 594 0 0.00 442.00 5 75 1.25 0.3 0.053 0.621 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 6 90 1.50 0.3 0.053 0.613 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 7 105 1.75 0.3 0.053 0.606 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 8 120 2.00 0.4 0.071 0.599 0.060 0.01 0.66 594 594 224,574 4,679 594 0 0.00 442.00 9 135 2.25 0.4 0.071 0.591 0.060 0.01 0.66 594 594 224,574 4,679 594 0 0.00 442.00 10 150 2.50 0.4 0.071 0.584 0.060 0.01 0.66 594 594 224,574 4,679 594 0 0.00 442.00 11 165 2.75 0.5 0.088 0.577 0.075 0.01 0.82 742 742 224,579 4,679 742 0 0.00 442.00 12 180 3.00 0.5 0.088 0.570 0.075 0.01 0.82 742 742 224,579 4,679 742 0 0.00 442.00 13 195 3.25 0.5 0.088 0.563 0.075 0.01 0.82 742 742 224,579 4,679 742 0 0.00 442.00 14 210 3.50 0.5 0.088 0.556 0.075 0.01 0.82 742 742 224,579 4,679 742 0 0.00 442.00 15 225 3.75 0.5 0.088 0.549 0.075 0.01 0.82 742 742 224,579 4,679 742 0 0.00 442.00 16 240 4.00 0.6 0.106 0.542 0.090 0.02 0.99 890 890 224,584 4,679 890 0 0.00 442.00 17 255 4.25 0.6 0.106 0.535 0.090 0.02 0.99 890 890 224,584 4,679 890 0 0.00 442.00 18 270 4.50 0.7 0.123 0.528 0.105 0.02 1.15 1,039 1,039 224,589 4,679 1,039 0 0.00 442.00 19 285 4.75 0.7 0.123 0.522 0.105 0.02 1.15 1,039 1,039 224,589 4,679 1,039 0 0.00 442.00 20 300 5.00 0.8 0.141 0.515 0.120 0.02 1.32 1,187 1,187 224,594 4,679 1,187 0 0.00 442.00 21 315 5.25 0.6 0.106 0.508 0.090 0.02 0.99 890 890 224,584 4,679 890 0 0.00 442.00 22 330 5.50 0.7 0.123 0.502 0.105 0.02 1.15 1,039 1,039 224,589 4,679 1,039 0 0.00 442.00 23 345 5.75 0.8 0.141 0.495 0.120 0.02 1.32 1,187 1,187 224,594 4,679 1,187 0 0.00 442.00 24 360 6.00 0.8 0.141 0.489 0.120 0.02 1.32 1,187 1,187 224,594 4,679 1,187 0 0.00 442.00 25 375 6.25 0.9 0.159 0.482 0.135 0.02 1.48 1,336 1,336 224,598 4,679 1,336 0 0.00 442.00 26 390 6.50 0.9 0.159 0.476 0.135 0.02 1.48 1,336 1,336 224,598 4,679 1,336 0 0.00 442.00 27 405 6.75 1.0 0.176 0.469 0.150 0.03 1.65 1,484 1,484 224,603 4,679 1,484 0 0.00 442.00 28 420 7.00 1.0 0.176 0.463 0.150 0.03 1.65 1,484 1,484 224,603 4,679 1,484 0 0.00 442.00 29 435 7.25 1.0 0.176 0.457 0.150 0.03 1.65 1,484 1,484 224,603 4,679 1,484 0 0.00 442.00 30 450 7.50 1.1 0.194 0.450 0.165 0.03 1.81 1,632 1,632 224,608 4,679 1,632 0 0.00 442.00 31 465 7.75 1.2 0.212 0.444 0.180 0.03 1.98 1,781 1,781 224,613 4,679 1,781 0 0.00 442.00 32 480 8.00 1.3 0.229 0.438 0.195 0.03 2.14 1,929 1,929 224,618 4,680 1,929 0 0.00 442.00 33 495 8.25 1.5 0.265 0.432 0.225 0.04 2.47 2,226 2,226 224,627 4,680 2,226 0 0.00 442.00 34 510 8.50 1.5 0.265 0.426 0.225 0.04 2.47 2,226 2,226 224,627 4,680 2,226 0 0.00 442.00 35 525 8.75 1.6 0.282 0.420 0.240 0.04 2.64 2,374 2,374 224,632 4,680 2,374 0 0.00 442.00 36 540 9.00 1.7 0.300 0.414 0.255 0.04 2.80 2,523 2,523 224,637 4,680 2,523 0 0.00 442.00 37 555 9.25 1.9 0.335 0.408 0.285 0.05 3.13 2,820 2,820 224,647 4,680 2,820 0 0.00 442.00 38 570 9.50 2.0 0.353 0.402 0.300 0.05 3.30 2,968 2,968 224,652 4,680 2,968 0 0.00 442.00 39 585 9.75 2.1 0.370 0.397 0.315 0.06 3.46 3,116 3,116 224,656 4,680 3,116 0 0.00 442.00 40 600 10.00 2.2 0.388 0.391 0.330 0.06 3.63 3,265 3,265 224,661 4,680 3,265 0 0.00 442.00 41 615 10.25 1.5 0.265 0.385 0.225 0.04 2.47 2,226 2,226 224,627 4,680 2,226 0 0.00 442.00 42 630 10.50 1.5 0.265 0.380 0.225 0.04 2.47 2,226 2,226 224,627 4,680 2,226 0 0.00 442.00 43 645 10.75 2.0 0.353 0.374 0.300 0.05 3.30 2,968 2,968 224,652 4,680 2,968 0 0.00 442.00 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 61.80 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.18 LAG TIME - MINUTES 3.54 C 0.00341 Maxwell Drywells UNIT TIME-PERCENT OF LAG 424%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 44 660 11.00 2.0 0.353 0.369 0.300 0.05 3.30 2,968 2,968 224,652 4,680 2,968 0 0.00 442.00 45 675 11.25 1.9 0.335 0.363 0.285 0.05 3.13 2,820 2,820 224,647 4,680 2,820 0 0.00 442.00 46 690 11.50 1.9 0.335 0.358 0.285 0.05 3.13 2,820 2,820 224,647 4,680 2,820 0 0.00 442.00 47 705 11.75 1.7 0.300 0.353 0.255 0.04 2.80 2,523 2,523 224,637 4,680 2,523 0 0.00 442.00 48 720 12.00 1.8 0.318 0.347 0.270 0.05 2.97 2,671 2,671 224,642 4,680 2,671 0 0.00 442.00 49 735 12.25 2.5 0.441 0.342 0.375 0.10 6.16 5,540 5,540 224,735 4,682 4,682 858 0.02 442.00 50 750 12.50 2.6 0.459 0.337 0.390 0.12 7.57 6,817 7,675 224,805 4,683 4,683 2,992 0.07 442.01 51 765 12.75 2.8 0.494 0.332 0.420 0.16 10.09 9,080 12,072 224,948 4,686 4,686 7,385 0.17 442.03 52 780 13.00 2.9 0.512 0.327 0.435 0.18 11.50 10,350 17,735 225,132 4,690 4,690 13,045 0.30 442.06 53 795 13.25 3.4 0.600 0.322 0.510 0.28 17.30 15,574 28,619 225,486 4,698 4,698 23,921 0.55 442.10 54 810 13.50 3.4 0.600 0.317 0.510 0.28 17.61 15,848 39,769 225,849 4,705 4,705 35,064 0.80 442.15 55 825 13.75 2.3 0.406 0.312 0.345 0.09 5.82 5,235 40,299 225,866 4,706 4,706 35,593 0.82 442.16 56 840 14.00 2.3 0.406 0.308 0.345 0.10 6.11 5,502 41,095 225,892 4,706 4,706 36,389 0.84 442.16 57 855 14.25 2.7 0.476 0.303 0.405 0.17 10.80 9,722 46,111 226,055 4,709 4,709 41,401 0.95 442.18 58 870 14.50 2.6 0.459 0.298 0.390 0.16 9.99 8,992 50,393 226,194 4,712 4,712 45,681 1.05 442.20 59 885 14.75 2.6 0.459 0.294 0.390 0.16 10.28 9,248 54,929 226,342 4,715 4,715 50,214 1.15 442.22 60 900 15.00 2.5 0.441 0.289 0.375 0.15 9.46 8,511 58,724 226,465 4,718 4,718 54,006 1.24 442.24 61 915 15.25 2.4 0.423 0.285 0.360 0.14 8.63 7,770 61,776 226,565 4,720 4,720 57,056 1.31 442.25 62 930 15.50 2.3 0.406 0.280 0.345 0.13 7.81 7,025 64,080 226,639 4,722 4,722 59,359 1.36 442.26 63 945 15.75 1.9 0.335 0.276 0.285 0.06 3.68 3,308 62,666 226,593 4,721 4,721 57,946 1.33 442.25 64 960 16.00 1.9 0.335 0.272 0.285 0.06 3.94 3,544 61,490 226,555 4,720 4,720 56,770 1.30 442.25 65 975 16.25 0.4 0.071 0.268 0.060 0.01 0.66 594 57,364 226,421 4,717 4,717 52,647 1.21 442.23 66 990 16.50 0.4 0.071 0.264 0.060 0.01 0.66 594 53,240 226,287 4,714 4,714 48,526 1.11 442.21 67 1005 16.75 0.3 0.053 0.260 0.045 0.01 0.49 445 48,971 226,148 4,711 4,711 44,260 1.02 442.19 68 1020 17.00 0.3 0.053 0.256 0.045 0.01 0.49 445 44,705 226,009 4,709 4,709 39,997 0.92 442.18 69 1035 17.25 0.5 0.088 0.252 0.075 0.01 0.82 742 40,739 225,880 4,706 4,706 36,033 0.83 442.16 70 1050 17.50 0.5 0.088 0.248 0.075 0.01 0.82 742 36,775 225,751 4,703 4,703 32,072 0.74 442.14 71 1065 17.75 0.5 0.088 0.244 0.075 0.01 0.82 742 32,814 225,622 4,700 4,700 28,113 0.65 442.12 72 1080 18.00 0.4 0.071 0.241 0.060 0.01 0.66 594 28,707 225,489 4,698 4,698 24,009 0.55 442.11 73 1095 18.25 0.4 0.071 0.237 0.060 0.01 0.66 594 24,603 225,355 4,695 4,695 19,908 0.46 442.09 74 1110 18.50 0.4 0.071 0.234 0.060 0.01 0.66 594 20,501 225,222 4,692 4,692 15,809 0.36 442.07 75 1125 18.75 0.3 0.053 0.230 0.045 0.01 0.49 445 16,254 225,084 4,689 4,689 11,565 0.27 442.05 76 1140 19.00 0.2 0.035 0.227 0.030 0.01 0.33 297 11,862 224,941 4,686 4,686 7,176 0.16 442.03 77 1155 19.25 0.3 0.053 0.224 0.045 0.01 0.49 445 7,621 224,803 4,683 4,683 2,938 0.07 442.01 78 1170 19.50 0.4 0.071 0.221 0.060 0.01 0.66 594 3,531 224,670 4,681 3,531 0 0.00 442.00 79 1185 19.75 0.3 0.053 0.218 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 80 1200 20.00 0.2 0.035 0.215 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 81 1215 20.25 0.3 0.053 0.212 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 82 1230 20.50 0.3 0.053 0.209 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 83 1245 20.75 0.3 0.053 0.207 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 84 1260 21.00 0.2 0.035 0.204 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 85 1275 21.25 0.3 0.053 0.202 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 86 1290 21.50 0.2 0.035 0.199 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 61.80 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.18 LAG TIME - MINUTES 3.54 C 0.00341 Maxwell Drywells UNIT TIME-PERCENT OF LAG 424%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 87 1305 21.75 0.3 0.053 0.197 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 88 1320 22.00 0.2 0.035 0.195 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 89 1335 22.25 0.3 0.053 0.193 0.045 0.01 0.49 445 445 224,569 4,679 445 0 0.00 442.00 90 1350 22.50 0.2 0.035 0.191 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 91 1365 22.75 0.2 0.035 0.190 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 92 1380 23.00 0.2 0.035 0.188 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 93 1395 23.25 0.2 0.035 0.187 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 94 1410 23.50 0.2 0.035 0.186 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 95 1425 23.75 0.2 0.035 0.185 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 96 1440 24.00 0.2 0.035 0.184 0.030 0.01 0.33 297 297 224,565 4,678 297 0 0.00 442.00 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 4.41 in 989,349 cu-ft 769,875 cu-ft 442.26 ft 17.61 cfs 219,473 cu-ft 152.41 cf/min 0.98 in 5.04 acft 219,473 cu-ft 1.36 acft 59,359 cu-ft Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 442 0 0 224,555 0 0 0.00 443 1 1 7,425 231,980 228,257 228,257 5.24 444 1 2 7,480 239,460 235,710 463,968 10.65 445 1 3 7,540 247,000 243,220 707,188 16.23 446 1 4 7,595 254,595 250,788 957,976 21.99 447 1 5 7,655 262,250 258,413 1,216,389 27.92 WHERE: TOTAL BASIN E BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 2 B PAVING/HARDSCAPE 0.316 D 56 0.51 1.00 4 B SF - LOW DENSITY 33.880 D 56 0.51 0.30 9 B LANDSCAPING 1.546 D 56 0.51 0.10 1,350 ft 675 ft 464.0 ft ELEVATION OF CONCENTRATION POINT 455.0 ft 0.02 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 450.0 ft 29,375 sf 451.0 ft 32,950 sf 452.0 ft 36,680 sf 453.0 ft 40,540 sf 454.0 ft 44,615 sf PERCOLATION RATE (in/hr)1.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-G RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 BASIN G AMC NUMBER Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)186,831 277,652 358,093 572,171 SOIL LOSSES (cu-ft)48,450 139,349 217,068 447,389 EFFECTIVE RAIN (in)1.07 1.07 1.09 0.96 FLOOD VOLUME (cu-ft)138,381 138,303 141,025 124,782 (acre-ft)3.18 3.17 3.24 2.86 REQUIRED STORAGE (cu-ft)135,473 129,934 125,173 79,376 (acre-ft)3.11 2.98 2.87 1.82 FACTOR OF SAFETY 1.09 1.13 1.18 1.85 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 62.43 53.39 10.03 MAXIMUM WSEL (ft)453.73 453.60 453.48 452.35 DEPTH (ft)3.73 3.60 3.48 2.35 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days)2.0 2.1 2.2 2.0 [18] 200% OF LAG-MINUTES RAINFALL DATA 8.0 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 147,099 3.38 0.02 [17] 100% OF LAG-MINUTES 4.0 4.0 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.07 [16] LAG TIME-MINUTES [13] L*LCA/S^0.5 5.93 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.006 675.00 [12] S^0.5 0.128 35.2 464 455 9 [3] AREA - ACRES [4] L-FEET [5] L-MILES 1350 0.256 BASIN G DA-G CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 35.742 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 100%0.05 0.316 0.009 0.0005 DEVELOPED 0.1000 0.0009 B 56 0.51 30%0.37 33.880 0.948 0.3529 DEVELOPED 0.6600 0.6256 B 56 0.51 10%0.46 1.546 0.043 0.0201 DEVELOPED 0.8200 0.0355 SUM 35.742 SUM 0.3734 0.6620 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.18671505 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00346 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00346 0.19 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.3734 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. (24-(T/60))^1.55 + LAND USE PAVING/HARDSCAPE SF - LOW DENSITY LANDSCAPING AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 35.74 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.37 0.53 0.25 8.96 2,688 2,688 29,684 206 206 2,482 0.06 450.08 2 10 0.17 4.2 0.73 0.37 0.62 0.35 12.70 3,809 6,292 30,097 209 209 6,083 0.14 450.20 3 15 0.25 4.4 0.76 0.37 0.65 0.39 13.94 4,183 10,266 30,553 212 212 10,054 0.23 450.32 4 20 0.33 4.6 0.79 0.37 0.68 0.42 15.19 4,557 14,610 31,052 216 216 14,395 0.33 450.46 5 25 0.42 5.0 0.86 0.37 0.73 0.49 17.68 5,304 19,699 31,636 220 220 19,479 0.45 450.63 6 30 0.50 5.6 0.97 0.37 0.82 0.59 21.42 6,425 25,904 32,348 225 225 25,679 0.59 450.82 7 35 0.58 6.4 1.11 0.37 0.94 0.73 26.40 7,920 33,599 33,213 231 231 33,368 0.77 451.06 8 40 0.67 8.1 1.40 0.37 1.19 1.03 36.99 11,096 44,464 34,378 239 239 44,225 1.02 451.38 9 45 0.75 13.1 2.26 0.37 1.92 1.89 68.12 20,437 64,663 36,543 254 254 64,409 1.48 451.96 10 50 0.83 34.5 5.96 0.37 5.07 5.59 201.40 60,419 124,828 42,483 295 295 124,533 2.86 453.47 11 55 0.92 6.7 1.16 0.37 0.98 0.78 28.27 8,480 133,013 43,266 300 300 132,713 3.05 453.66 12 60 1.00 3.8 0.66 0.37 0.56 0.28 10.21 3,062 135,775 43,531 302 302 135,473 3.11 453.73 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 186,831 cu-ft SOIL LOSSES 48,450 cu-ft EFFECTIVE RAIN 1.07 in FLOOD VOLUME 3.18 acft FLOOD VOLUME 138,381 cu-ft REQUIRED STORAGE 3.11 REQUIRED STORAGE 135,473 cu-ft MAX WSEL 453.73 ft PEAK FLOW RATE 201.40 cfs TOTAL BASIN LOSSES 2,908 cu-ft AVERAGE PERCOLATION RATE 48.47 cf/min EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 35.74 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.37 0.28 0.05 1.80 541 541 29,437 204 204 337 0.01 450.01 2 10 0.17 1.3 0.33 0.37 0.28 0.05 1.80 541 878 29,476 205 205 674 0.02 450.02 3 15 0.25 1.1 0.28 0.37 0.24 0.04 1.53 458 1,132 29,505 205 205 927 0.02 450.03 4 20 0.33 1.5 0.39 0.37 0.33 0.01 0.42 127 1,054 29,496 205 205 849 0.02 450.03 5 25 0.42 1.5 0.39 0.37 0.33 0.01 0.42 127 977 29,487 205 205 772 0.02 450.02 6 30 0.50 1.8 0.46 0.37 0.39 0.09 3.20 960 1,732 29,574 205 205 1,527 0.04 450.05 7 35 0.58 1.5 0.39 0.37 0.33 0.01 0.42 127 1,654 29,565 205 205 1,449 0.03 450.05 8 40 0.67 1.8 0.46 0.37 0.39 0.09 3.20 960 2,409 29,651 206 206 2,203 0.05 450.07 9 45 0.75 1.8 0.46 0.37 0.39 0.09 3.20 960 3,163 29,738 207 207 2,957 0.07 450.09 10 50 0.83 1.5 0.39 0.37 0.33 0.01 0.42 127 3,084 29,729 206 206 2,877 0.07 450.09 11 55 0.92 1.6 0.41 0.37 0.35 0.04 1.35 405 3,282 29,752 207 207 3,076 0.07 450.10 12 60 1.00 1.8 0.46 0.37 0.39 0.09 3.20 960 4,036 29,838 207 207 3,829 0.09 450.12 13 65 1.08 2.2 0.56 0.37 0.48 0.19 6.90 2,071 5,900 30,052 209 209 5,691 0.13 450.18 14 70 1.17 2.2 0.56 0.37 0.48 0.19 6.90 2,071 7,762 30,266 210 210 7,552 0.17 450.24 15 75 1.25 2.2 0.56 0.37 0.48 0.19 6.90 2,071 9,622 30,479 212 212 9,411 0.22 450.30 16 80 1.33 2.0 0.51 0.37 0.44 0.14 5.05 1,516 10,926 30,629 213 213 10,713 0.25 450.34 17 85 1.42 2.6 0.67 0.37 0.57 0.29 10.60 3,181 13,895 30,970 215 215 13,680 0.31 450.44 18 90 1.50 2.7 0.69 0.37 0.59 0.32 11.53 3,459 17,139 31,342 218 218 16,921 0.39 450.54 19 95 1.58 2.4 0.62 0.37 0.52 0.24 8.75 2,626 19,547 31,619 220 220 19,328 0.44 450.62 20 100 1.67 2.7 0.69 0.37 0.59 0.32 11.53 3,459 22,787 31,991 222 222 22,565 0.52 450.72 21 105 1.75 3.3 0.85 0.37 0.72 0.47 17.08 5,125 27,690 32,553 226 226 27,464 0.63 450.88 22 110 1.83 3.1 0.80 0.37 0.68 0.42 15.23 4,570 32,033 33,045 229 229 31,804 0.73 451.02 23 115 1.92 2.9 0.74 0.37 0.63 0.37 13.38 4,014 35,818 33,451 232 232 35,586 0.82 451.13 24 120 2.00 3.0 0.77 0.37 0.65 0.40 14.31 4,292 39,878 33,886 235 235 39,643 0.91 451.24 25 125 2.08 3.1 0.80 0.37 0.68 0.42 15.23 4,570 44,212 34,351 239 239 43,974 1.01 451.37 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 35.74 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses 26 130 2.17 4.2 1.08 0.37 0.92 0.71 25.41 7,624 51,598 35,142 244 244 51,354 1.18 451.58 27 135 2.25 5.0 1.28 0.37 1.09 0.91 32.82 9,845 61,199 36,171 251 251 60,948 1.40 451.86 28 140 2.33 3.5 0.90 0.37 0.76 0.53 18.93 5,680 66,628 36,748 255 255 66,373 1.52 452.01 29 145 2.42 6.8 1.75 0.37 1.48 1.37 49.48 14,843 81,215 38,207 265 265 80,950 1.86 452.39 30 150 2.50 7.3 1.87 0.37 1.59 1.50 54.10 16,231 97,181 39,804 276 276 96,905 2.22 452.80 31 155 2.58 8.2 2.11 0.37 1.79 1.73 62.43 18,730 115,635 41,602 289 289 115,346 2.65 453.25 32 160 2.67 5.9 1.52 0.37 1.29 1.14 41.15 12,344 127,690 42,757 297 297 127,393 2.92 453.54 33 165 2.75 2.0 0.51 0.37 0.44 0.14 5.05 1,516 128,908 42,873 298 298 128,611 2.95 453.57 34 170 2.83 1.8 0.46 0.37 0.39 0.09 3.20 960 129,571 42,937 298 298 129,273 2.97 453.58 35 175 2.92 1.8 0.46 0.37 0.39 0.09 3.20 960 130,233 43,000 299 299 129,934 2.98 453.60 36 180 3.00 0.6 0.15 0.37 0.13 0.02 0.83 250 130,184 42,996 299 299 129,886 2.98 453.60 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY 8,418 cu-ft 46.76 cf/min 1.07 in 3.17 acft 138,303 cu-ft 2.98 acft 129,934 cu-ft 139,349 cu-ft 2.14 in 277,652 cu-ft 453.60 ft 62.43 cfs Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 35.74 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.37 0.14 0.02 0.90 269 269 29,406 204 204 64 0.00 450.00 2 10 0.17 0.6 0.20 0.37 0.17 0.03 1.07 322 387 29,419 204 204 182 0.00 450.01 3 15 0.25 0.6 0.20 0.37 0.17 0.03 1.07 322 505 29,433 204 204 300 0.01 450.01 4 20 0.33 0.6 0.20 0.37 0.17 0.03 1.07 322 623 29,446 204 204 418 0.01 450.01 5 25 0.42 0.6 0.20 0.37 0.17 0.03 1.07 322 740 29,460 205 205 536 0.01 450.02 6 30 0.50 0.7 0.23 0.37 0.20 0.03 1.25 376 912 29,480 205 205 707 0.02 450.02 7 35 0.58 0.7 0.23 0.37 0.20 0.03 1.25 376 1,083 29,499 205 205 878 0.02 450.03 8 40 0.67 0.7 0.23 0.37 0.20 0.03 1.25 376 1,254 29,519 205 205 1,049 0.02 450.03 9 45 0.75 0.7 0.23 0.37 0.20 0.03 1.25 376 1,425 29,539 205 205 1,220 0.03 450.04 10 50 0.83 0.7 0.23 0.37 0.20 0.03 1.25 376 1,596 29,558 205 205 1,391 0.03 450.04 11 55 0.92 0.7 0.23 0.37 0.20 0.03 1.25 376 1,767 29,578 205 205 1,561 0.04 450.05 12 60 1.00 0.8 0.26 0.37 0.23 0.04 1.43 430 1,991 29,604 206 206 1,785 0.04 450.06 13 65 1.08 0.8 0.26 0.37 0.23 0.04 1.43 430 2,215 29,629 206 206 2,009 0.05 450.06 14 70 1.17 0.8 0.26 0.37 0.23 0.04 1.43 430 2,439 29,655 206 206 2,233 0.05 450.07 15 75 1.25 0.8 0.26 0.37 0.23 0.04 1.43 430 2,663 29,681 206 206 2,457 0.06 450.08 16 80 1.33 0.8 0.26 0.37 0.23 0.04 1.43 430 2,887 29,706 206 206 2,680 0.06 450.09 17 85 1.42 0.8 0.26 0.37 0.23 0.04 1.43 430 3,110 29,732 206 206 2,903 0.07 450.09 18 90 1.50 0.8 0.26 0.37 0.23 0.04 1.43 430 3,333 29,758 207 207 3,127 0.07 450.10 19 95 1.58 0.8 0.26 0.37 0.23 0.04 1.43 430 3,556 29,783 207 207 3,349 0.08 450.11 20 100 1.67 0.8 0.26 0.37 0.23 0.04 1.43 430 3,779 29,809 207 207 3,572 0.08 450.11 21 105 1.75 0.8 0.26 0.37 0.23 0.04 1.43 430 4,002 29,834 207 207 3,795 0.09 450.12 22 110 1.83 0.8 0.26 0.37 0.23 0.04 1.43 430 4,224 29,860 207 207 4,017 0.09 450.13 23 115 1.92 0.8 0.26 0.37 0.23 0.04 1.43 430 4,447 29,885 208 208 4,239 0.10 450.14 24 120 2.00 0.9 0.30 0.37 0.25 0.04 1.61 483 4,723 29,917 208 208 4,515 0.10 450.14 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 35.74 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.37 0.23 0.04 1.43 430 4,945 29,943 208 208 4,737 0.11 450.15 26 130 2.17 0.9 0.30 0.37 0.25 0.04 1.61 483 5,220 29,974 208 208 5,012 0.12 450.16 27 135 2.25 0.9 0.30 0.37 0.25 0.04 1.61 483 5,495 30,006 208 208 5,287 0.12 450.17 28 140 2.33 0.9 0.30 0.37 0.25 0.04 1.61 483 5,770 30,037 209 209 5,562 0.13 450.18 29 145 2.42 0.9 0.30 0.37 0.25 0.04 1.61 483 6,045 30,069 209 209 5,836 0.13 450.19 30 150 2.50 0.9 0.30 0.37 0.25 0.04 1.61 483 6,320 30,100 209 209 6,111 0.14 450.20 31 155 2.58 0.9 0.30 0.37 0.25 0.04 1.61 483 6,594 30,132 209 209 6,385 0.15 450.21 32 160 2.67 0.9 0.30 0.37 0.25 0.04 1.61 483 6,868 30,163 209 209 6,659 0.15 450.21 33 165 2.75 1.0 0.33 0.37 0.28 0.05 1.79 537 7,196 30,201 210 210 6,986 0.16 450.22 34 170 2.83 1.0 0.33 0.37 0.28 0.05 1.79 537 7,523 30,239 210 210 7,313 0.17 450.23 35 175 2.92 1.0 0.33 0.37 0.28 0.05 1.79 537 7,851 30,276 210 210 7,640 0.18 450.25 36 180 3.00 1.0 0.33 0.37 0.28 0.05 1.79 537 8,178 30,314 211 211 7,967 0.18 450.26 37 185 3.08 1.0 0.33 0.37 0.28 0.05 1.79 537 8,504 30,351 211 211 8,293 0.19 450.27 38 190 3.17 1.1 0.36 0.37 0.31 0.05 1.97 591 8,884 30,395 211 211 8,673 0.20 450.28 39 195 3.25 1.1 0.36 0.37 0.31 0.05 1.97 591 9,264 30,438 211 211 9,053 0.21 450.29 40 200 3.33 1.1 0.36 0.37 0.31 0.05 1.97 591 9,643 30,482 212 212 9,432 0.22 450.30 41 205 3.42 1.2 0.40 0.37 0.34 0.02 0.87 260 9,691 30,487 212 212 9,480 0.22 450.30 42 210 3.50 1.3 0.43 0.37 0.37 0.06 2.06 618 10,097 30,534 212 212 9,885 0.23 450.32 43 215 3.58 1.4 0.46 0.37 0.39 0.09 3.25 976 10,861 30,622 213 213 10,648 0.24 450.34 44 220 3.67 1.4 0.46 0.37 0.39 0.09 3.25 976 11,624 30,709 213 213 11,411 0.26 450.37 45 225 3.75 1.5 0.50 0.37 0.42 0.12 4.45 1,334 12,745 30,838 214 214 12,531 0.29 450.40 46 230 3.83 1.5 0.50 0.37 0.42 0.12 4.45 1,334 13,865 30,966 215 215 13,650 0.31 450.44 47 235 3.92 1.6 0.53 0.37 0.45 0.16 5.64 1,692 15,341 31,136 216 216 15,125 0.35 450.49 48 240 4.00 1.6 0.53 0.37 0.45 0.16 5.64 1,692 16,817 31,305 217 217 16,600 0.38 450.53 49 245 4.08 1.7 0.56 0.37 0.48 0.19 6.83 2,050 18,650 31,516 219 219 18,431 0.42 450.59 50 250 4.17 1.8 0.60 0.37 0.51 0.22 8.03 2,408 20,839 31,767 221 221 20,619 0.47 450.66 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 35.74 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.37 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.37 0.53 0.26 9.22 2,766 23,385 32,059 223 223 23,162 0.53 450.74 52 260 4.33 2.0 0.66 0.37 0.56 0.29 10.41 3,124 26,287 32,392 225 225 26,062 0.60 450.84 53 265 4.42 2.1 0.70 0.37 0.59 0.32 11.61 3,482 29,544 32,766 228 228 29,317 0.67 450.94 54 270 4.50 2.1 0.70 0.37 0.59 0.32 11.61 3,482 32,799 33,127 230 230 32,569 0.75 451.04 55 275 4.58 2.2 0.73 0.37 0.62 0.36 12.80 3,841 36,409 33,514 233 233 36,177 0.83 451.14 56 280 4.67 2.3 0.76 0.37 0.65 0.39 14.00 4,199 40,375 33,939 236 236 40,140 0.92 451.26 57 285 4.75 2.4 0.79 0.37 0.68 0.42 15.19 4,557 44,696 34,403 239 239 44,457 1.02 451.38 58 290 4.83 2.4 0.79 0.37 0.68 0.42 15.19 4,557 49,014 34,865 242 242 48,772 1.12 451.51 59 295 4.92 2.5 0.83 0.37 0.70 0.45 16.38 4,915 53,687 35,366 246 246 53,441 1.23 451.64 60 300 5.00 2.6 0.86 0.37 0.73 0.49 17.58 5,273 58,714 35,905 249 249 58,465 1.34 451.79 61 305 5.08 3.1 1.03 0.37 0.87 0.65 23.54 7,063 65,528 36,635 254 254 65,274 1.50 451.98 62 310 5.17 3.6 1.19 0.37 1.01 0.82 29.51 8,854 74,128 37,499 260 260 73,867 1.70 452.21 63 315 5.25 3.9 1.29 0.37 1.10 0.92 33.09 9,928 83,795 38,465 267 267 83,528 1.92 452.46 64 320 5.33 4.2 1.39 0.37 1.18 1.02 36.67 11,002 94,531 39,539 275 275 94,256 2.16 452.73 65 325 5.42 4.7 1.56 0.37 1.32 1.18 42.64 12,793 107,049 40,780 283 283 106,766 2.45 453.05 66 330 5.50 5.6 1.85 0.37 1.58 1.48 53.39 16,016 122,781 42,287 294 294 122,488 2.81 453.42 67 335 5.58 1.9 0.63 0.37 0.53 0.26 9.22 2,766 125,254 42,523 295 295 124,959 2.87 453.48 68 340 5.67 0.9 0.30 0.37 0.25 0.04 1.61 483 125,442 42,541 295 295 125,147 2.87 453.48 69 345 5.75 0.6 0.20 0.37 0.17 0.03 1.07 322 125,469 42,544 295 295 125,173 2.87 453.48 70 350 5.83 0.5 0.17 0.37 0.14 0.02 0.90 269 125,442 42,541 295 295 125,147 2.87 453.48 71 355 5.92 0.3 0.10 0.37 0.08 0.01 0.54 161 125,308 42,529 295 295 125,012 2.87 453.48 72 360 6.00 0.2 0.07 0.37 0.06 0.01 0.36 107 125,120 42,511 295 295 124,825 2.87 453.48 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY 45.00 cf/min 16,201 cu-ft 1.09 in 3.24 acft 141,025 cu-ft 2.87 acft 125,173 cu-ft 358,093 cu-ft 2.76 in 217,068 cu-ft 453.48 ft 53.39 cfs Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 35.74 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.19 LAG TIME - MINUTES 3.99 C 0.00346 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.659 0.030 0.01 0.19 172 172 29,395 612 172 0 0.00 450.00 2 30 0.50 0.3 0.053 0.652 0.045 0.01 0.29 257 257 29,405 613 257 0 0.00 450.00 3 45 0.75 0.3 0.053 0.644 0.045 0.01 0.29 257 257 29,405 613 257 0 0.00 450.00 4 60 1.00 0.4 0.071 0.637 0.060 0.01 0.38 343 343 29,414 613 343 0 0.00 450.00 5 75 1.25 0.3 0.053 0.629 0.045 0.01 0.29 257 257 29,405 613 257 0 0.00 450.00 6 90 1.50 0.3 0.053 0.622 0.045 0.01 0.29 257 257 29,405 613 257 0 0.00 450.00 7 105 1.75 0.3 0.053 0.614 0.045 0.01 0.29 257 257 29,405 613 257 0 0.00 450.00 8 120 2.00 0.4 0.071 0.607 0.060 0.01 0.38 343 343 29,414 613 343 0 0.00 450.00 9 135 2.25 0.4 0.071 0.599 0.060 0.01 0.38 343 343 29,414 613 343 0 0.00 450.00 10 150 2.50 0.4 0.071 0.592 0.060 0.01 0.38 343 343 29,414 613 343 0 0.00 450.00 11 165 2.75 0.5 0.088 0.585 0.075 0.01 0.48 429 429 29,424 613 429 0 0.00 450.00 12 180 3.00 0.5 0.088 0.578 0.075 0.01 0.48 429 429 29,424 613 429 0 0.00 450.00 13 195 3.25 0.5 0.088 0.571 0.075 0.01 0.48 429 429 29,424 613 429 0 0.00 450.00 14 210 3.50 0.5 0.088 0.564 0.075 0.01 0.48 429 429 29,424 613 429 0 0.00 450.00 15 225 3.75 0.5 0.088 0.556 0.075 0.01 0.48 429 429 29,424 613 429 0 0.00 450.00 16 240 4.00 0.6 0.106 0.549 0.090 0.02 0.57 515 515 29,434 613 515 0 0.00 450.00 17 255 4.25 0.6 0.106 0.542 0.090 0.02 0.57 515 515 29,434 613 515 0 0.00 450.00 18 270 4.50 0.7 0.123 0.536 0.105 0.02 0.67 601 601 29,444 613 601 0 0.00 450.00 19 285 4.75 0.7 0.123 0.529 0.105 0.02 0.67 601 601 29,444 613 601 0 0.00 450.00 20 300 5.00 0.8 0.141 0.522 0.120 0.02 0.76 687 687 29,454 614 614 73 0.00 450.00 21 315 5.25 0.6 0.106 0.515 0.090 0.02 0.57 515 588 29,442 613 588 0 0.00 450.00 22 330 5.50 0.7 0.123 0.508 0.105 0.02 0.67 601 601 29,444 613 601 0 0.00 450.00 23 345 5.75 0.8 0.141 0.502 0.120 0.02 0.76 687 687 29,454 614 614 73 0.00 450.00 24 360 6.00 0.8 0.141 0.495 0.120 0.02 0.76 687 760 29,462 614 614 146 0.00 450.00 25 375 6.25 0.9 0.159 0.489 0.135 0.02 0.86 772 918 29,480 614 614 304 0.01 450.01 26 390 6.50 0.9 0.159 0.482 0.135 0.02 0.86 772 1,076 29,499 615 615 462 0.01 450.01 27 405 6.75 1.0 0.176 0.476 0.150 0.03 0.95 858 1,320 29,527 615 615 705 0.02 450.02 28 420 7.00 1.0 0.176 0.469 0.150 0.03 0.95 858 1,563 29,554 616 616 948 0.02 450.03 29 435 7.25 1.0 0.176 0.463 0.150 0.03 0.95 858 1,806 29,582 616 616 1,190 0.03 450.04 30 450 7.50 1.1 0.194 0.456 0.165 0.03 1.05 944 2,134 29,620 617 617 1,517 0.03 450.05 31 465 7.75 1.2 0.212 0.450 0.180 0.03 1.14 1,030 2,546 29,667 618 618 1,928 0.04 450.06 32 480 8.00 1.3 0.229 0.444 0.195 0.03 1.24 1,116 3,044 29,724 619 619 2,425 0.06 450.08 33 495 8.25 1.5 0.265 0.438 0.225 0.04 1.43 1,287 3,712 29,801 621 621 3,091 0.07 450.10 34 510 8.50 1.5 0.265 0.432 0.225 0.04 1.43 1,287 4,379 29,878 622 622 3,756 0.09 450.12 35 525 8.75 1.6 0.282 0.426 0.240 0.04 1.53 1,373 5,130 29,964 624 624 4,505 0.10 450.14 36 540 9.00 1.7 0.300 0.420 0.255 0.04 1.62 1,459 5,964 30,060 626 626 5,338 0.12 450.17 37 555 9.25 1.9 0.335 0.414 0.285 0.05 1.81 1,631 6,969 30,175 629 629 6,340 0.15 450.20 38 570 9.50 2.0 0.353 0.408 0.300 0.05 1.91 1,717 8,057 30,300 631 631 7,425 0.17 450.24 39 585 9.75 2.1 0.370 0.402 0.315 0.06 2.00 1,802 9,228 30,434 634 634 8,594 0.20 450.28 40 600 10.00 2.2 0.388 0.396 0.330 0.06 2.10 1,888 10,482 30,578 637 637 9,845 0.23 450.32 41 615 10.25 1.5 0.265 0.391 0.225 0.04 1.43 1,287 11,132 30,653 639 639 10,494 0.24 450.34 42 630 10.50 1.5 0.265 0.385 0.225 0.04 1.43 1,287 11,781 30,727 640 640 11,141 0.26 450.36 43 645 10.75 2.0 0.353 0.379 0.300 0.05 1.91 1,717 12,857 30,851 643 643 12,215 0.28 450.39 in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 35.74 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.19 LAG TIME - MINUTES 3.99 C 0.00346 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses 44 660 11.00 2.0 0.353 0.374 0.300 0.05 1.91 1,717 13,931 30,974 645 645 13,286 0.30 450.43 45 675 11.25 1.9 0.335 0.368 0.285 0.05 1.81 1,631 14,917 31,087 648 648 14,269 0.33 450.46 46 690 11.50 1.9 0.335 0.363 0.285 0.05 1.81 1,631 15,900 31,200 650 650 15,250 0.35 450.49 47 705 11.75 1.7 0.300 0.357 0.255 0.04 1.62 1,459 16,709 31,293 652 652 16,057 0.37 450.52 48 720 12.00 1.8 0.318 0.352 0.270 0.05 1.72 1,545 17,602 31,395 654 654 16,947 0.39 450.54 49 735 12.25 2.5 0.441 0.347 0.375 0.09 3.39 3,054 20,002 31,671 660 660 19,342 0.44 450.62 50 750 12.50 2.6 0.459 0.342 0.390 0.12 4.22 3,795 23,136 32,031 667 667 22,469 0.52 450.72 51 765 12.75 2.8 0.494 0.337 0.420 0.16 5.67 5,106 27,575 32,540 678 678 26,897 0.62 450.86 52 780 13.00 2.9 0.512 0.331 0.435 0.18 6.49 5,842 32,739 33,121 690 690 32,049 0.74 451.03 53 795 13.25 3.4 0.600 0.326 0.510 0.27 9.85 8,866 40,915 33,997 708 708 40,206 0.92 451.26 54 810 13.50 3.4 0.600 0.321 0.510 0.28 10.03 9,026 49,233 34,889 727 727 48,506 1.11 451.50 55 825 13.75 2.3 0.406 0.317 0.345 0.09 3.21 2,891 51,396 35,121 732 732 50,665 1.16 451.56 56 840 14.00 2.3 0.406 0.312 0.345 0.09 3.39 3,047 53,712 35,369 737 737 52,975 1.22 451.63 57 855 14.25 2.7 0.476 0.307 0.405 0.17 6.10 5,490 58,465 35,878 747 747 57,717 1.32 451.76 58 870 14.50 2.6 0.459 0.302 0.390 0.16 5.63 5,070 62,787 36,342 757 757 62,030 1.42 451.89 59 885 14.75 2.6 0.459 0.298 0.390 0.16 5.80 5,220 67,249 36,811 767 767 66,482 1.53 452.01 60 900 15.00 2.5 0.441 0.293 0.375 0.15 5.33 4,795 71,278 37,213 775 775 70,502 1.62 452.12 61 915 15.25 2.4 0.423 0.289 0.360 0.13 4.85 4,369 74,871 37,573 783 783 74,088 1.70 452.21 62 930 15.50 2.3 0.406 0.284 0.345 0.12 4.38 3,940 78,028 37,889 789 789 77,238 1.77 452.29 63 945 15.75 1.9 0.335 0.280 0.285 0.06 1.99 1,792 79,030 37,989 791 791 78,239 1.80 452.32 64 960 16.00 1.9 0.335 0.276 0.285 0.06 2.15 1,931 80,169 38,103 794 794 79,376 1.82 452.35 65 975 16.25 0.4 0.071 0.271 0.060 0.01 0.38 343 79,719 38,058 793 793 78,926 1.81 452.34 66 990 16.50 0.4 0.071 0.267 0.060 0.01 0.38 343 79,269 38,013 792 792 78,477 1.80 452.32 67 1005 16.75 0.3 0.053 0.263 0.045 0.01 0.29 257 78,735 37,959 791 791 77,944 1.79 452.31 68 1020 17.00 0.3 0.053 0.259 0.045 0.01 0.29 257 78,202 37,906 790 790 77,412 1.78 452.30 69 1035 17.25 0.5 0.088 0.255 0.075 0.01 0.48 429 77,841 37,870 789 789 77,052 1.77 452.29 70 1050 17.50 0.5 0.088 0.252 0.075 0.01 0.48 429 77,481 37,834 788 788 76,693 1.76 452.28 71 1065 17.75 0.5 0.088 0.248 0.075 0.01 0.48 429 77,122 37,798 787 787 76,335 1.75 452.27 72 1080 18.00 0.4 0.071 0.244 0.060 0.01 0.38 343 76,678 37,754 787 787 75,891 1.74 452.26 73 1095 18.25 0.4 0.071 0.241 0.060 0.01 0.38 343 76,235 37,709 786 786 75,449 1.73 452.25 74 1110 18.50 0.4 0.071 0.237 0.060 0.01 0.38 343 75,792 37,665 785 785 75,008 1.72 452.23 75 1125 18.75 0.3 0.053 0.234 0.045 0.01 0.29 257 75,265 37,612 784 784 74,482 1.71 452.22 76 1140 19.00 0.2 0.035 0.230 0.030 0.01 0.19 172 74,653 37,551 782 782 73,871 1.70 452.21 77 1155 19.25 0.3 0.053 0.227 0.045 0.01 0.29 257 74,128 37,499 781 781 73,347 1.68 452.19 78 1170 19.50 0.4 0.071 0.224 0.060 0.01 0.38 343 73,691 37,455 780 780 72,910 1.67 452.18 79 1185 19.75 0.3 0.053 0.221 0.045 0.01 0.29 257 73,168 37,403 779 779 72,388 1.66 452.17 80 1200 20.00 0.2 0.035 0.218 0.030 0.01 0.19 172 72,560 37,342 778 778 71,782 1.65 452.15 81 1215 20.25 0.3 0.053 0.215 0.045 0.01 0.29 257 72,040 37,290 777 777 71,263 1.64 452.14 82 1230 20.50 0.3 0.053 0.212 0.045 0.01 0.29 257 71,520 37,238 776 776 70,744 1.62 452.12 83 1245 20.75 0.3 0.053 0.209 0.045 0.01 0.29 257 71,002 37,186 775 775 70,227 1.61 452.11 84 1260 21.00 0.2 0.035 0.207 0.030 0.01 0.19 172 70,399 37,126 773 773 69,625 1.60 452.10 85 1275 21.25 0.3 0.053 0.204 0.045 0.01 0.29 257 69,883 37,074 772 772 69,111 1.59 452.08 86 1290 21.50 0.2 0.035 0.202 0.030 0.01 0.19 172 69,282 37,014 771 771 68,511 1.57 452.07 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 35.74 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.19 LAG TIME - MINUTES 3.99 C 0.00346 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses 87 1305 21.75 0.3 0.053 0.200 0.045 0.01 0.29 257 68,769 36,963 770 770 67,998 1.56 452.05 88 1320 22.00 0.2 0.035 0.198 0.030 0.01 0.19 172 68,170 36,903 769 769 67,401 1.55 452.04 89 1335 22.25 0.3 0.053 0.196 0.045 0.01 0.29 257 67,659 36,852 768 768 66,891 1.54 452.02 90 1350 22.50 0.2 0.035 0.194 0.030 0.01 0.19 172 67,063 36,792 766 766 66,296 1.52 452.01 91 1365 22.75 0.2 0.035 0.192 0.030 0.01 0.19 172 66,468 36,732 765 765 65,703 1.51 451.99 92 1380 23.00 0.2 0.035 0.191 0.030 0.01 0.19 172 65,874 36,673 764 764 65,110 1.49 451.98 93 1395 23.25 0.2 0.035 0.190 0.030 0.01 0.19 172 65,282 36,609 763 763 64,519 1.48 451.96 94 1410 23.50 0.2 0.035 0.188 0.030 0.01 0.19 172 64,691 36,546 761 761 63,929 1.47 451.94 95 1425 23.75 0.2 0.035 0.187 0.030 0.01 0.19 172 64,101 36,482 760 760 63,341 1.45 451.93 96 1440 24.00 0.2 0.035 0.187 0.030 0.01 0.19 172 63,513 36,419 759 759 62,754 1.44 451.91 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 62,028 cu-ft 43.08 cf/min 0.96 in 2.86 acft 124,782 cu-ft 1.82 acft 79,376 cu-ft 4.41 in 572,171 cu-ft 447,389 cu-ft 452.35 ft 10.03 cfs Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 450 0 0 29,375 0 0 0.00 451 1 1 3,575 32,950 31,145 31,145 0.71 452 1 2 3,730 36,680 34,798 65,944 1.51 453 1 3 3,860 40,540 38,594 104,538 2.40 454 1 4 4,075 44,615 42,561 147,099 3.38 WHERE: TOTAL BASIN G BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 1 B COMMERCIAL 7.118 D 56 0.51 0.90 1,350 ft 675 ft 464.0 ft ELEVATION OF CONCENTRATION POINT 455.0 ft 0.02 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 448.0 ft 13,135 sf 449.0 ft 19,390 sf 450.0 ft 21,415 sf 451.0 ft 26,025 sf PERCOLATION RATE (in/hr)1.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 BASIN H AMC NUMBER RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-H Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)37,207 55,294 71,314 113,948 SOIL LOSSES (cu-ft)2,504 7,511 14,935 46,429 EFFECTIVE RAIN (in)1.34 1.85 2.18 2.61 FLOOD VOLUME (cu-ft)34,704 47,783 56,379 67,518 (acre-ft)0.80 1.10 1.29 1.55 REQUIRED STORAGE (cu-ft)33,264 43,319 47,929 49,089 (acre-ft)0.76 0.99 1.10 1.13 FACTOR OF SAFETY 1.81 1.39 1.26 1.23 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 14.42 12.62 3.71 MAXIMUM WSEL (ft)449.84 450.29 450.48 450.53 DEPTH (ft)1.84 2.29 2.48 2.53 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days)1.0 1.3 1.6 2.1 BASIN H DA-H CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 7.118 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION [3] AREA - ACRES [4] L-FEET [5] L-MILES 1350 0.256 [13] L*LCA/S^0.5 5.93 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.006 675.00 [12] S^0.5 0.128 35.2 464 455 9 0.02 [17] 100% OF LAG-MINUTES 4.0 4.0 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.07 [16] LAG TIME-MINUTES [18] 200% OF LAG-MINUTES RAINFALL DATA 8.0 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 60,238 1.38 Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 90%0.10 7.118 1.000 0.0969 DEVELOPED 0.1800 0.1800 SUM 7.118 SUM 0.0969 0.1800 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.04845 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00090 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00090 0.05 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.0969 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II (24-(T/60))^1.55 + LAND USE COMMERCIAL Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 7.12 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.10 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.10 0.53 0.53 3.77 1,131 1,131 13,573 94 94 1,037 0.02 448.06 2 10 0.17 4.2 0.73 0.10 0.62 0.63 4.51 1,354 2,391 14,060 98 98 2,293 0.05 448.14 3 15 0.25 4.4 0.76 0.10 0.65 0.66 4.76 1,428 3,721 14,575 101 101 3,620 0.08 448.22 4 20 0.33 4.6 0.79 0.10 0.68 0.70 5.01 1,503 5,123 15,118 105 105 5,018 0.12 448.31 5 25 0.42 5.0 0.86 0.10 0.73 0.77 5.51 1,652 6,670 15,716 109 109 6,561 0.15 448.41 6 30 0.50 5.6 0.97 0.10 0.82 0.87 6.25 1,875 8,436 16,400 114 114 8,322 0.19 448.51 7 35 0.58 6.4 1.11 0.10 0.94 1.01 7.24 2,173 10,494 17,197 119 119 10,375 0.24 448.64 8 40 0.67 8.1 1.40 0.10 1.19 1.30 9.35 2,805 13,180 18,236 127 127 13,054 0.30 448.81 9 45 0.75 13.1 2.26 0.10 1.92 2.17 15.55 4,666 17,719 19,545 136 136 17,583 0.40 449.07 10 50 0.83 34.5 5.96 0.10 5.07 5.86 42.09 12,628 30,211 20,785 144 144 30,067 0.69 449.68 11 55 0.92 6.7 1.16 0.10 0.98 1.06 7.61 2,284 32,351 20,998 146 146 32,205 0.74 449.79 12 60 1.00 3.8 0.66 0.10 0.56 0.56 4.02 1,205 33,411 21,103 147 147 33,264 0.76 449.84 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 37,207 cu-ft SOIL LOSSES 2,504 cu-ft EFFECTIVE RAIN 1.34 in FLOOD VOLUME 0.80 acft FLOOD VOLUME 34,704 cu-ft REQUIRED STORAGE 0.76 REQUIRED STORAGE 33,264 cu-ft MAX WSEL 449.84 ft PEAK FLOW RATE 42.09 cfs TOTAL BASIN LOSSES 1,440 cu-ft AVERAGE PERCOLATION RATE 23.99 cf/min CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 7.12 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.10 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.10 0.28 0.24 1.70 510 510 13,332 93 93 418 0.01 448.03 2 10 0.17 1.3 0.33 0.10 0.28 0.24 1.70 510 928 13,494 94 94 834 0.02 448.05 3 15 0.25 1.1 0.28 0.10 0.24 0.19 1.33 400 1,234 13,612 95 95 1,139 0.03 448.07 4 20 0.33 1.5 0.39 0.10 0.33 0.29 2.07 621 1,760 13,816 96 96 1,664 0.04 448.10 5 25 0.42 1.5 0.39 0.10 0.33 0.29 2.07 621 2,285 14,019 97 97 2,187 0.05 448.14 6 30 0.50 1.8 0.46 0.10 0.39 0.37 2.62 787 2,974 14,286 99 99 2,875 0.07 448.18 7 35 0.58 1.5 0.39 0.10 0.33 0.29 2.07 621 3,496 14,488 101 101 3,395 0.08 448.21 8 40 0.67 1.8 0.46 0.10 0.39 0.37 2.62 787 4,182 14,753 102 102 4,079 0.09 448.25 9 45 0.75 1.8 0.46 0.10 0.39 0.37 2.62 787 4,866 15,018 104 104 4,762 0.11 448.29 10 50 0.83 1.5 0.39 0.10 0.33 0.29 2.07 621 5,382 15,218 106 106 5,277 0.12 448.33 11 55 0.92 1.6 0.41 0.10 0.35 0.31 2.25 676 5,953 15,439 107 107 5,845 0.13 448.36 12 60 1.00 1.8 0.46 0.10 0.39 0.37 2.62 787 6,632 15,702 109 109 6,523 0.15 448.40 13 65 1.08 2.2 0.56 0.10 0.48 0.47 3.36 1,008 7,531 16,050 111 111 7,419 0.17 448.46 14 70 1.17 2.2 0.56 0.10 0.48 0.47 3.36 1,008 8,427 16,397 114 114 8,313 0.19 448.51 15 75 1.25 2.2 0.56 0.10 0.48 0.47 3.36 1,008 9,321 16,743 116 116 9,205 0.21 448.57 16 80 1.33 2.0 0.51 0.10 0.44 0.42 2.99 897 10,102 17,045 118 118 9,984 0.23 448.62 17 85 1.42 2.6 0.67 0.10 0.57 0.57 4.10 1,229 11,213 17,475 121 121 11,091 0.25 448.69 18 90 1.50 2.7 0.69 0.10 0.59 0.60 4.28 1,284 12,376 17,925 124 124 12,251 0.28 448.76 19 95 1.58 2.4 0.62 0.10 0.52 0.52 3.73 1,118 13,370 18,310 127 127 13,243 0.30 448.82 20 100 1.67 2.7 0.69 0.10 0.59 0.60 4.28 1,284 14,527 18,757 130 130 14,397 0.33 448.89 21 105 1.75 3.3 0.85 0.10 0.72 0.75 5.39 1,616 16,013 19,332 134 134 15,878 0.36 448.98 22 110 1.83 3.1 0.80 0.10 0.68 0.70 5.02 1,505 17,384 19,511 135 135 17,248 0.40 449.05 23 115 1.92 2.9 0.74 0.10 0.63 0.65 4.65 1,395 18,643 19,636 136 136 18,507 0.42 449.12 24 120 2.00 3.0 0.77 0.10 0.65 0.67 4.83 1,450 19,957 19,767 137 137 19,820 0.45 449.18 25 125 2.08 3.1 0.80 0.10 0.68 0.70 5.02 1,505 21,325 19,903 138 138 21,187 0.49 449.25 Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 7.12 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.10 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD 26 130 2.17 4.2 1.08 0.10 0.92 0.98 7.05 2,114 23,301 20,099 140 140 23,161 0.53 449.34 27 135 2.25 5.0 1.28 0.10 1.09 1.19 8.52 2,556 25,717 20,339 141 141 25,576 0.59 449.46 28 140 2.33 3.5 0.90 0.10 0.76 0.80 5.76 1,727 27,303 20,496 142 142 27,160 0.62 449.54 29 145 2.42 6.8 1.75 0.10 1.48 1.65 11.84 3,551 30,712 20,835 145 145 30,567 0.70 449.71 30 150 2.50 7.3 1.87 0.10 1.59 1.78 12.76 3,828 34,395 21,200 147 147 34,248 0.79 449.89 31 155 2.58 8.2 2.11 0.10 1.79 2.01 14.42 4,325 38,573 21,808 151 151 38,422 0.88 450.08 32 160 2.67 5.9 1.52 0.10 1.29 1.42 10.18 3,054 41,475 22,373 155 155 41,320 0.95 450.20 33 165 2.75 2.0 0.51 0.10 0.44 0.42 2.99 897 42,217 22,517 156 156 42,061 0.97 450.23 34 170 2.83 1.8 0.46 0.10 0.39 0.37 2.62 787 42,848 22,640 157 157 42,690 0.98 450.26 35 175 2.92 1.8 0.46 0.10 0.39 0.37 2.62 787 43,477 22,762 158 158 43,319 0.99 450.29 36 180 3.00 0.6 0.15 0.10 0.13 0.06 0.41 123 43,442 22,756 158 158 43,284 0.99 450.28 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 7,511 cu-ft 2.14 in 55,294 cu-ft 450.29 ft 14.42 cfs 4,499 cu-ft 24.99 cf/min 1.85 in 1.10 acft 47,783 cu-ft 0.99 acft 43,319 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 7.12 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.10 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.10 0.14 0.07 0.49 148 148 13,192 92 92 56 0.00 448.00 2 10 0.17 0.6 0.20 0.10 0.17 0.10 0.73 219 276 13,242 92 92 184 0.00 448.01 3 15 0.25 0.6 0.20 0.10 0.17 0.10 0.73 219 403 13,291 92 92 311 0.01 448.02 4 20 0.33 0.6 0.20 0.10 0.17 0.10 0.73 219 530 13,340 93 93 437 0.01 448.03 5 25 0.42 0.6 0.20 0.10 0.17 0.10 0.73 219 656 13,389 93 93 563 0.01 448.03 6 30 0.50 0.7 0.23 0.10 0.20 0.13 0.97 291 854 13,466 94 94 760 0.02 448.05 7 35 0.58 0.7 0.23 0.10 0.20 0.13 0.97 291 1,051 13,542 94 94 957 0.02 448.06 8 40 0.67 0.7 0.23 0.10 0.20 0.13 0.97 291 1,248 13,618 95 95 1,153 0.03 448.07 9 45 0.75 0.7 0.23 0.10 0.20 0.13 0.97 291 1,443 13,694 95 95 1,348 0.03 448.08 10 50 0.83 0.7 0.23 0.10 0.20 0.13 0.97 291 1,639 13,769 96 96 1,543 0.04 448.10 11 55 0.92 0.7 0.23 0.10 0.20 0.13 0.97 291 1,834 13,845 96 96 1,738 0.04 448.11 12 60 1.00 0.8 0.26 0.10 0.23 0.17 1.21 362 2,100 13,948 97 97 2,003 0.05 448.12 13 65 1.08 0.8 0.26 0.10 0.23 0.17 1.21 362 2,365 14,050 98 98 2,267 0.05 448.14 14 70 1.17 0.8 0.26 0.10 0.23 0.17 1.21 362 2,629 14,152 98 98 2,531 0.06 448.16 15 75 1.25 0.8 0.26 0.10 0.23 0.17 1.21 362 2,892 14,254 99 99 2,794 0.06 448.17 16 80 1.33 0.8 0.26 0.10 0.23 0.17 1.21 362 3,155 14,356 100 100 3,056 0.07 448.19 17 85 1.42 0.8 0.26 0.10 0.23 0.17 1.21 362 3,418 14,458 100 100 3,317 0.08 448.21 18 90 1.50 0.8 0.26 0.10 0.23 0.17 1.21 362 3,679 14,559 101 101 3,578 0.08 448.22 19 95 1.58 0.8 0.26 0.10 0.23 0.17 1.21 362 3,940 14,660 102 102 3,838 0.09 448.24 20 100 1.67 0.8 0.26 0.10 0.23 0.17 1.21 362 4,200 14,760 103 103 4,097 0.09 448.25 21 105 1.75 0.8 0.26 0.10 0.23 0.17 1.21 362 4,459 14,861 103 103 4,356 0.10 448.27 22 110 1.83 0.8 0.26 0.10 0.23 0.17 1.21 362 4,718 14,961 104 104 4,614 0.11 448.29 23 115 1.92 0.8 0.26 0.10 0.23 0.17 1.21 362 4,976 15,061 105 105 4,871 0.11 448.30 24 120 2.00 0.9 0.30 0.10 0.25 0.20 1.44 433 5,304 15,188 105 105 5,199 0.12 448.32 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 7.12 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.10 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.10 0.23 0.17 1.21 362 5,561 15,287 106 106 5,455 0.13 448.34 26 130 2.17 0.9 0.30 0.10 0.25 0.20 1.44 433 5,888 15,414 107 107 5,781 0.13 448.36 27 135 2.25 0.9 0.30 0.10 0.25 0.20 1.44 433 6,214 15,540 108 108 6,106 0.14 448.38 28 140 2.33 0.9 0.30 0.10 0.25 0.20 1.44 433 6,539 15,666 109 109 6,430 0.15 448.40 29 145 2.42 0.9 0.30 0.10 0.25 0.20 1.44 433 6,864 15,791 110 110 6,754 0.16 448.42 30 150 2.50 0.9 0.30 0.10 0.25 0.20 1.44 433 7,187 15,917 111 111 7,077 0.16 448.44 31 155 2.58 0.9 0.30 0.10 0.25 0.20 1.44 433 7,510 16,042 111 111 7,398 0.17 448.46 32 160 2.67 0.9 0.30 0.10 0.25 0.20 1.44 433 7,832 16,166 112 112 7,719 0.18 448.48 33 165 2.75 1.0 0.33 0.10 0.28 0.23 1.68 504 8,224 16,318 113 113 8,111 0.19 448.50 34 170 2.83 1.0 0.33 0.10 0.28 0.23 1.68 504 8,615 16,469 114 114 8,501 0.20 448.53 35 175 2.92 1.0 0.33 0.10 0.28 0.23 1.68 504 9,005 16,620 115 115 8,890 0.20 448.55 36 180 3.00 1.0 0.33 0.10 0.28 0.23 1.68 504 9,394 16,771 116 116 9,278 0.21 448.57 37 185 3.08 1.0 0.33 0.10 0.28 0.23 1.68 504 9,782 16,921 118 118 9,665 0.22 448.60 38 190 3.17 1.1 0.36 0.10 0.31 0.27 1.92 576 10,241 17,098 119 119 10,122 0.23 448.63 39 195 3.25 1.1 0.36 0.10 0.31 0.27 1.92 576 10,698 17,275 120 120 10,578 0.24 448.65 40 200 3.33 1.1 0.36 0.10 0.31 0.27 1.92 576 11,153 17,452 121 121 11,032 0.25 448.68 41 205 3.42 1.2 0.40 0.10 0.34 0.30 2.16 647 11,679 17,655 123 123 11,557 0.27 448.72 42 210 3.50 1.3 0.43 0.10 0.37 0.33 2.39 718 12,275 17,886 124 124 12,151 0.28 448.75 43 215 3.58 1.4 0.46 0.10 0.39 0.37 2.63 790 12,941 18,144 126 126 12,815 0.29 448.79 44 220 3.67 1.4 0.46 0.10 0.39 0.37 2.63 790 13,605 18,400 128 128 13,477 0.31 448.83 45 225 3.75 1.5 0.50 0.10 0.42 0.40 2.87 861 14,338 18,684 130 130 14,208 0.33 448.88 46 230 3.83 1.5 0.50 0.10 0.42 0.40 2.87 861 15,069 18,967 132 132 14,937 0.34 448.92 47 235 3.92 1.6 0.53 0.10 0.45 0.43 3.11 932 15,870 19,277 134 134 15,736 0.36 448.97 48 240 4.00 1.6 0.53 0.10 0.45 0.43 3.11 932 16,668 19,440 135 135 16,533 0.38 449.02 49 245 4.08 1.7 0.56 0.10 0.48 0.47 3.35 1,004 17,537 19,527 136 136 17,401 0.40 449.06 50 250 4.17 1.8 0.60 0.10 0.51 0.50 3.58 1,075 18,476 19,620 136 136 18,340 0.42 449.11 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 7.12 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.10 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.10 0.53 0.53 3.82 1,146 19,486 19,720 137 137 19,350 0.44 449.16 52 260 4.33 2.0 0.66 0.10 0.56 0.57 4.06 1,218 20,567 19,827 138 138 20,429 0.47 449.21 53 265 4.42 2.1 0.70 0.10 0.59 0.60 4.30 1,289 21,718 19,942 138 138 21,580 0.50 449.27 54 270 4.50 2.1 0.70 0.10 0.59 0.60 4.30 1,289 22,869 20,056 139 139 22,730 0.52 449.32 55 275 4.58 2.2 0.73 0.10 0.62 0.63 4.53 1,360 24,090 20,177 140 140 23,950 0.55 449.38 56 280 4.67 2.3 0.76 0.10 0.65 0.66 4.77 1,432 25,381 20,305 141 141 25,240 0.58 449.45 57 285 4.75 2.4 0.79 0.10 0.68 0.70 5.01 1,503 26,743 20,441 142 142 26,601 0.61 449.51 58 290 4.83 2.4 0.79 0.10 0.68 0.70 5.01 1,503 28,104 20,576 143 143 27,961 0.64 449.58 59 295 4.92 2.5 0.83 0.10 0.70 0.73 5.25 1,574 29,535 20,718 144 144 29,392 0.67 449.65 60 300 5.00 2.6 0.86 0.10 0.73 0.76 5.49 1,646 31,037 20,867 145 145 30,892 0.71 449.72 61 305 5.08 3.1 1.03 0.10 0.87 0.93 6.67 2,002 32,894 21,051 146 146 32,748 0.75 449.81 62 310 5.17 3.6 1.19 0.10 1.01 1.10 7.86 2,359 35,107 21,271 148 148 34,959 0.80 449.92 63 315 5.25 3.9 1.29 0.10 1.10 1.19 8.58 2,573 37,532 21,605 150 150 37,382 0.86 450.03 64 320 5.33 4.2 1.39 0.10 1.18 1.29 9.29 2,787 40,168 22,118 154 154 40,015 0.92 450.15 65 325 5.42 4.7 1.56 0.10 1.32 1.46 10.48 3,143 43,158 22,700 158 158 43,000 0.99 450.27 66 330 5.50 5.6 1.85 0.10 1.58 1.76 12.62 3,785 46,785 23,406 163 163 46,622 1.07 450.43 67 335 5.58 1.9 0.63 0.10 0.53 0.53 3.82 1,146 47,769 23,598 164 164 47,605 1.09 450.47 68 340 5.67 0.9 0.30 0.10 0.25 0.20 1.44 433 48,038 23,650 164 164 47,874 1.10 450.48 69 345 5.75 0.6 0.20 0.10 0.17 0.10 0.73 219 48,093 23,661 164 164 47,929 1.10 450.48 70 350 5.83 0.5 0.17 0.10 0.14 0.07 0.49 148 48,077 23,658 164 164 47,912 1.10 450.48 71 355 5.92 0.3 0.10 0.10 0.08 0.00 0.02 5 47,918 23,627 164 164 47,754 1.10 450.47 72 360 6.00 0.2 0.07 0.10 0.06 0.01 0.07 21 47,775 23,599 164 164 47,611 1.09 450.47 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 71,314 cu-ft 2.76 in 14,935 cu-ft 450.48 ft 12.62 cfs 24.36 cf/min 8,768 cu-ft 2.18 in 1.29 acft 56,379 cu-ft 1.10 acft 47,929 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 7.12 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.05 LAG TIME - MINUTES 3.99 C 0.00090 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.171 0.030 0.01 0.04 34 34 13,148 274 34 0 0.00 448.00 2 30 0.50 0.3 0.053 0.169 0.045 0.01 0.06 51 51 13,155 274 51 0 0.00 448.00 3 45 0.75 0.3 0.053 0.167 0.045 0.01 0.06 51 51 13,155 274 51 0 0.00 448.00 4 60 1.00 0.4 0.071 0.165 0.060 0.01 0.08 68 68 13,161 274 68 0 0.00 448.00 5 75 1.25 0.3 0.053 0.163 0.045 0.01 0.06 51 51 13,155 274 51 0 0.00 448.00 6 90 1.50 0.3 0.053 0.161 0.045 0.01 0.06 51 51 13,155 274 51 0 0.00 448.00 7 105 1.75 0.3 0.053 0.159 0.045 0.01 0.06 51 51 13,155 274 51 0 0.00 448.00 8 120 2.00 0.4 0.071 0.157 0.060 0.01 0.08 68 68 13,161 274 68 0 0.00 448.00 9 135 2.25 0.4 0.071 0.156 0.060 0.01 0.08 68 68 13,161 274 68 0 0.00 448.00 10 150 2.50 0.4 0.071 0.154 0.060 0.01 0.08 68 68 13,161 274 68 0 0.00 448.00 11 165 2.75 0.5 0.088 0.152 0.075 0.01 0.09 85 85 13,168 274 85 0 0.00 448.00 12 180 3.00 0.5 0.088 0.150 0.075 0.01 0.09 85 85 13,168 274 85 0 0.00 448.00 13 195 3.25 0.5 0.088 0.148 0.075 0.01 0.09 85 85 13,168 274 85 0 0.00 448.00 14 210 3.50 0.5 0.088 0.146 0.075 0.01 0.09 85 85 13,168 274 85 0 0.00 448.00 15 225 3.75 0.5 0.088 0.144 0.075 0.01 0.09 85 85 13,168 274 85 0 0.00 448.00 16 240 4.00 0.6 0.106 0.143 0.090 0.02 0.11 103 103 13,175 274 103 0 0.00 448.00 17 255 4.25 0.6 0.106 0.141 0.090 0.02 0.11 103 103 13,175 274 103 0 0.00 448.00 18 270 4.50 0.7 0.123 0.139 0.105 0.02 0.13 120 120 13,181 275 120 0 0.00 448.00 19 285 4.75 0.7 0.123 0.137 0.105 0.02 0.13 120 120 13,181 275 120 0 0.00 448.00 20 300 5.00 0.8 0.141 0.135 0.120 0.01 0.04 37 37 13,149 274 37 0 0.00 448.00 21 315 5.25 0.6 0.106 0.134 0.090 0.02 0.11 103 103 13,175 274 103 0 0.00 448.00 22 330 5.50 0.7 0.123 0.132 0.105 0.02 0.13 120 120 13,181 275 120 0 0.00 448.00 23 345 5.75 0.8 0.141 0.130 0.120 0.01 0.08 71 71 13,162 274 71 0 0.00 448.00 24 360 6.00 0.8 0.141 0.128 0.120 0.01 0.09 82 82 13,167 274 82 0 0.00 448.00 25 375 6.25 0.9 0.159 0.127 0.135 0.03 0.23 207 207 13,215 275 207 0 0.00 448.00 26 390 6.50 0.9 0.159 0.125 0.135 0.03 0.24 218 218 13,219 275 218 0 0.00 448.00 27 405 6.75 1.0 0.176 0.123 0.150 0.05 0.38 342 342 13,268 276 276 66 0.00 448.00 28 420 7.00 1.0 0.176 0.122 0.150 0.05 0.39 353 419 13,297 277 277 142 0.00 448.01 29 435 7.25 1.0 0.176 0.120 0.150 0.06 0.40 364 506 13,331 278 278 228 0.01 448.01 30 450 7.50 1.1 0.194 0.118 0.165 0.08 0.54 488 716 13,412 279 279 437 0.01 448.03 31 465 7.75 1.2 0.212 0.117 0.180 0.09 0.68 613 1,050 13,541 282 282 768 0.02 448.05 32 480 8.00 1.3 0.229 0.115 0.195 0.11 0.82 737 1,505 13,717 286 286 1,219 0.03 448.08 33 495 8.25 1.5 0.265 0.114 0.225 0.15 1.08 975 2,194 13,984 291 291 1,903 0.04 448.12 34 510 8.50 1.5 0.265 0.112 0.225 0.15 1.10 986 2,888 14,253 297 297 2,591 0.06 448.16 35 525 8.75 1.6 0.282 0.110 0.240 0.17 1.23 1,110 3,701 14,567 303 303 3,398 0.08 448.21 36 540 9.00 1.7 0.300 0.109 0.255 0.19 1.37 1,234 4,631 14,927 311 311 4,320 0.10 448.27 37 555 9.25 1.9 0.335 0.107 0.285 0.23 1.63 1,471 5,792 15,377 320 320 5,471 0.13 448.34 38 570 9.50 2.0 0.353 0.106 0.300 0.25 1.77 1,595 7,067 15,870 331 331 6,736 0.15 448.42 39 585 9.75 2.1 0.370 0.104 0.315 0.27 1.91 1,719 8,455 16,407 342 342 8,113 0.19 448.50 40 600 10.00 2.2 0.388 0.103 0.330 0.29 2.05 1,843 9,956 16,988 354 354 9,602 0.22 448.59 41 615 10.25 1.5 0.265 0.101 0.225 0.16 1.17 1,055 10,657 17,259 360 360 10,297 0.24 448.64 42 630 10.50 1.5 0.265 0.100 0.225 0.16 1.18 1,064 11,361 17,532 365 365 10,996 0.25 448.68 43 645 10.75 2.0 0.353 0.098 0.300 0.25 1.83 1,643 12,639 18,027 376 376 12,264 0.28 448.76 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 7.12 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.05 LAG TIME - MINUTES 3.99 C 0.00090 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 44 660 11.00 2.0 0.353 0.097 0.300 0.26 1.84 1,653 13,916 18,521 386 386 13,530 0.31 448.84 45 675 11.25 1.9 0.335 0.096 0.285 0.24 1.72 1,548 15,078 18,971 395 395 14,683 0.34 448.91 46 690 11.50 1.9 0.335 0.094 0.285 0.24 1.73 1,557 16,240 19,398 404 404 15,836 0.36 448.98 47 705 11.75 1.7 0.300 0.093 0.255 0.21 1.49 1,338 17,174 19,491 406 406 16,768 0.38 449.03 48 720 12.00 1.8 0.318 0.091 0.270 0.23 1.62 1,461 18,228 19,595 408 408 17,820 0.41 449.08 49 735 12.25 2.5 0.441 0.090 0.375 0.35 2.52 2,267 20,088 19,780 412 412 19,675 0.45 449.17 50 750 12.50 2.6 0.459 0.089 0.390 0.37 2.66 2,390 22,065 19,976 416 416 21,649 0.50 449.27 51 765 12.75 2.8 0.494 0.087 0.420 0.41 2.92 2,626 24,276 20,196 421 421 23,855 0.55 449.38 52 780 13.00 2.9 0.512 0.086 0.435 0.43 3.05 2,749 26,604 20,427 426 426 26,178 0.60 449.49 53 795 13.25 3.4 0.600 0.085 0.510 0.52 3.70 3,327 29,505 20,715 432 432 29,074 0.67 449.63 54 810 13.50 3.4 0.600 0.083 0.510 0.52 3.71 3,335 32,409 21,003 438 438 31,972 0.73 449.78 55 825 13.75 2.3 0.406 0.082 0.345 0.32 2.32 2,090 34,062 21,167 441 441 33,621 0.77 449.86 56 840 14.00 2.3 0.406 0.081 0.345 0.32 2.33 2,098 35,719 21,332 444 444 35,274 0.81 449.94 57 855 14.25 2.7 0.476 0.080 0.405 0.40 2.85 2,562 37,836 21,664 451 451 37,385 0.86 450.04 58 870 14.50 2.6 0.459 0.078 0.390 0.38 2.73 2,456 39,841 22,055 459 459 39,381 0.90 450.12 59 885 14.75 2.6 0.459 0.077 0.390 0.38 2.74 2,464 41,845 22,445 468 468 41,377 0.95 450.20 60 900 15.00 2.5 0.441 0.076 0.375 0.36 2.62 2,357 43,735 22,813 475 475 43,260 0.99 450.28 61 915 15.25 2.4 0.423 0.075 0.360 0.35 2.50 2,251 45,510 23,158 482 482 45,028 1.03 450.36 62 930 15.50 2.3 0.406 0.074 0.345 0.33 2.38 2,144 47,172 23,482 489 489 46,683 1.07 450.43 63 945 15.75 1.9 0.335 0.073 0.285 0.26 1.88 1,696 48,379 23,717 494 494 47,885 1.10 450.48 64 960 16.00 1.9 0.335 0.072 0.285 0.26 1.89 1,703 49,588 23,952 499 499 49,089 1.13 450.53 65 975 16.25 0.4 0.071 0.070 0.060 0.00 0.00 1 49,090 23,855 497 497 48,593 1.12 450.51 66 990 16.50 0.4 0.071 0.069 0.060 0.00 0.01 8 48,600 23,760 495 495 48,105 1.10 450.49 67 1005 16.75 0.3 0.053 0.068 0.045 0.01 0.06 51 48,157 23,673 493 493 47,663 1.09 450.47 68 1020 17.00 0.3 0.053 0.067 0.045 0.01 0.06 51 47,715 23,587 491 491 47,223 1.08 450.45 69 1035 17.25 0.5 0.088 0.066 0.075 0.02 0.16 142 47,365 23,519 490 490 46,875 1.08 450.44 70 1050 17.50 0.5 0.088 0.065 0.075 0.02 0.16 148 47,023 23,453 489 489 46,535 1.07 450.42 71 1065 17.75 0.5 0.088 0.064 0.075 0.02 0.17 154 46,689 23,388 487 487 46,202 1.06 450.41 72 1080 18.00 0.4 0.071 0.063 0.060 0.01 0.05 47 46,248 23,302 485 485 45,763 1.05 450.39 73 1095 18.25 0.4 0.071 0.062 0.060 0.01 0.06 53 45,816 23,218 484 484 45,332 1.04 450.37 74 1110 18.50 0.4 0.071 0.061 0.060 0.01 0.07 59 45,390 23,135 482 482 44,908 1.03 450.35 75 1125 18.75 0.3 0.053 0.061 0.045 0.01 0.06 51 44,960 23,051 480 480 44,479 1.02 450.33 76 1140 19.00 0.2 0.035 0.060 0.030 0.01 0.04 34 44,514 22,964 478 478 44,035 1.01 450.32 77 1155 19.25 0.3 0.053 0.059 0.045 0.01 0.06 51 44,087 22,881 477 477 43,610 1.00 450.30 78 1170 19.50 0.4 0.071 0.058 0.060 0.01 0.09 81 43,690 22,804 475 475 43,215 0.99 450.28 79 1185 19.75 0.3 0.053 0.057 0.045 0.01 0.06 51 43,267 22,721 473 473 42,793 0.98 450.26 80 1200 20.00 0.2 0.035 0.057 0.030 0.01 0.04 34 42,827 22,636 472 472 42,356 0.97 450.24 81 1215 20.25 0.3 0.053 0.056 0.045 0.01 0.06 51 42,407 22,554 470 470 41,937 0.96 450.23 82 1230 20.50 0.3 0.053 0.055 0.045 0.01 0.06 51 41,989 22,473 468 468 41,520 0.95 450.21 83 1245 20.75 0.3 0.053 0.054 0.045 0.01 0.06 51 41,572 22,391 466 466 41,105 0.94 450.19 84 1260 21.00 0.2 0.035 0.054 0.030 0.01 0.04 34 41,139 22,307 465 465 40,675 0.93 450.17 85 1275 21.25 0.3 0.053 0.053 0.045 0.01 0.06 51 40,726 22,227 463 463 40,263 0.92 450.16 86 1290 21.50 0.2 0.035 0.052 0.030 0.01 0.04 34 40,297 22,143 461 461 39,836 0.91 450.14 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 7.12 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.05 LAG TIME - MINUTES 3.99 C 0.00090 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 87 1305 21.75 0.3 0.053 0.052 0.045 0.00 0.01 7 39,842 22,055 459 459 39,383 0.90 450.12 88 1320 22.00 0.2 0.035 0.051 0.030 0.01 0.04 34 39,417 21,972 458 458 38,959 0.89 450.10 89 1335 22.25 0.3 0.053 0.051 0.045 0.00 0.02 14 38,973 21,886 456 456 38,517 0.88 450.08 90 1350 22.50 0.2 0.035 0.050 0.030 0.01 0.04 34 38,551 21,803 454 454 38,097 0.87 450.07 91 1365 22.75 0.2 0.035 0.050 0.030 0.01 0.04 34 38,131 21,722 453 453 37,679 0.86 450.05 92 1380 23.00 0.2 0.035 0.050 0.030 0.01 0.04 34 37,713 21,640 451 451 37,262 0.86 450.03 93 1395 23.25 0.2 0.035 0.049 0.030 0.01 0.04 34 37,296 21,559 449 449 36,847 0.85 450.01 94 1410 23.50 0.2 0.035 0.049 0.030 0.01 0.04 34 36,881 21,478 447 447 36,434 0.84 449.99 95 1425 23.75 0.2 0.035 0.049 0.030 0.01 0.04 34 36,468 21,406 446 446 36,022 0.83 449.97 96 1440 24.00 0.2 0.035 0.048 0.030 0.01 0.04 34 36,056 21,365 445 445 35,611 0.82 449.95 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 4.41 in 113,948 cu-ft 46,429 cu-ft 450.53 ft 3.71 cfs 31,908 cu-ft 22.16 cf/min 2.61 in 1.55 acft 67,518 cu-ft 1.13 acft 49,089 cu-ft Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 448 0 0 13,135 0 0 0.00 449 1 1 6,255 19,390 16,161 16,161 0.37 450 1 2 2,025 21,415 20,394 36,555 0.84 451 1 3 4,610 26,025 23,683 60,238 1.38 WHERE: TOTAL BASIN H BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 2 B PAVING/HARDSCAPE 0.470 D 56 0.51 1.00 4 B SF - LOW DENSITY 47.890 D 56 0.51 0.30 9 B LANDSCAPING 3.269 D 56 0.51 0.10 1,350 ft 675 ft 464.0 ft ELEVATION OF CONCENTRATION POINT 455.0 ft 0.02 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 438.0 ft 49,700 sf 439.0 ft 54,375 sf 440.0 ft 59,209 sf 441.0 ft 64,195 sf 442.0 ft 69,345 sf PERCOLATION RATE (in/hr)1.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 BASIN I AMC NUMBER RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention DA-I Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)269,876 401,066 517,263 826,496 SOIL LOSSES (cu-ft)70,315 202,167 314,294 647,343 EFFECTIVE RAIN (in)1.06 1.06 1.08 0.96 FLOOD VOLUME (cu-ft)199,561 198,899 202,969 179,153 (acre-ft)4.58 4.57 4.66 4.11 REQUIRED STORAGE (cu-ft)194,891 185,355 177,030 108,262 (acre-ft)4.47 4.26 4.06 2.49 FACTOR OF SAFETY 1.22 1.28 1.34 2.19 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 90.09 77.02 14.41 MAXIMUM WSEL (ft)441.37 441.22 441.10 439.99 DEPTH (ft)3.37 3.22 3.10 1.99 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days)1.8 1.8 1.9 1.8 BASIN I DA-I CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 51.629 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION [3] AREA - ACRES [4] L-FEET [5] L-MILES 1350 0.256 [13] L*LCA/S^0.5 5.93 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.006 675.00 [12] S^0.5 0.128 35.2 464 455 9 0.02 [17] 100% OF LAG-MINUTES 4.0 4.0 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.07 [16] LAG TIME-MINUTES [18] 200% OF LAG-MINUTES RAINFALL DATA 8.0 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 237,233 5.45 Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 100%0.05 0.470 0.009 0.0005 DEVELOPED 0.1000 0.0009 B 56 0.51 30%0.37 47.890 0.928 0.3453 DEVELOPED 0.6600 0.6122 B 56 0.51 10%0.46 3.269 0.063 0.0294 DEVELOPED 0.8200 0.0519 SUM 51.629 SUM 0.3752 0.6650 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.187593793 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00347 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00347 0.19 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.3752 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II (24-(T/60))^1.55 + LAND USE PAVING/HARDSCAPE SF - LOW DENSITY LANDSCAPING Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 51.63 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.38 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.38 0.53 0.25 12.85 3,856 3,856 50,047 348 348 3,508 0.08 438.07 2 10 0.17 4.2 0.73 0.38 0.62 0.35 18.25 5,475 8,984 50,507 351 351 8,633 0.20 438.17 3 15 0.25 4.4 0.76 0.38 0.65 0.39 20.05 6,015 14,648 51,016 354 354 14,293 0.33 438.27 4 20 0.33 4.6 0.79 0.38 0.68 0.42 21.85 6,555 20,848 51,574 358 358 20,490 0.47 438.39 5 25 0.42 5.0 0.86 0.38 0.73 0.49 25.45 7,634 28,124 52,228 363 363 27,762 0.64 438.53 6 30 0.50 5.6 0.97 0.38 0.82 0.59 30.84 9,253 37,015 53,027 368 368 36,647 0.84 438.70 7 35 0.58 6.4 1.11 0.38 0.94 0.73 38.04 11,412 48,059 54,019 375 375 47,684 1.09 438.92 8 40 0.67 8.1 1.40 0.38 1.19 1.02 53.33 16,000 63,684 55,368 385 385 63,300 1.45 439.20 9 45 0.75 13.1 2.26 0.38 1.92 1.89 98.31 29,494 92,794 57,847 402 402 92,392 2.12 439.71 10 50 0.83 34.5 5.96 0.38 5.07 5.59 290.83 87,248 179,640 64,902 451 451 179,189 4.11 441.13 11 55 0.92 6.7 1.16 0.38 0.98 0.78 40.74 12,222 191,411 65,810 457 457 190,954 4.38 441.31 12 60 1.00 3.8 0.66 0.38 0.56 0.28 14.65 4,396 195,350 66,114 459 459 194,891 4.47 441.37 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 269,876 cu-ft SOIL LOSSES 70,315 cu-ft EFFECTIVE RAIN 1.06 in FLOOD VOLUME 4.58 acft FLOOD VOLUME 199,561 cu-ft REQUIRED STORAGE 4.47 REQUIRED STORAGE 194,891 cu-ft MAX WSEL 441.37 ft PEAK FLOW RATE 290.83 cfs TOTAL BASIN LOSSES 4,670 cu-ft AVERAGE PERCOLATION RATE 77.83 cf/min CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 51.63 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.38 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.38 0.28 0.05 2.61 782 782 49,770 346 346 436 0.01 438.01 2 10 0.17 1.3 0.33 0.38 0.28 0.05 2.61 782 1,219 49,810 346 346 873 0.02 438.02 3 15 0.25 1.1 0.28 0.38 0.24 0.04 2.21 662 1,534 49,838 346 346 1,188 0.03 438.02 4 20 0.33 1.5 0.39 0.38 0.33 0.01 0.52 156 1,345 49,821 346 346 999 0.02 438.02 5 25 0.42 1.5 0.39 0.38 0.33 0.01 0.52 156 1,155 49,804 346 346 809 0.02 438.02 6 30 0.50 1.8 0.46 0.38 0.39 0.09 4.53 1,360 2,169 49,895 346 346 1,822 0.04 438.04 7 35 0.58 1.5 0.39 0.38 0.33 0.01 0.52 156 1,979 49,878 346 346 1,632 0.04 438.03 8 40 0.67 1.8 0.46 0.38 0.39 0.09 4.53 1,360 2,992 49,969 347 347 2,645 0.06 438.05 9 45 0.75 1.8 0.46 0.38 0.39 0.09 4.53 1,360 4,004 50,060 348 348 3,657 0.08 438.07 10 50 0.83 1.5 0.39 0.38 0.33 0.01 0.52 156 3,813 50,043 348 348 3,466 0.08 438.07 11 55 0.92 1.6 0.41 0.38 0.35 0.04 1.86 557 4,023 50,062 348 348 3,675 0.08 438.07 12 60 1.00 1.8 0.46 0.38 0.39 0.09 4.53 1,360 5,035 50,152 348 348 4,687 0.11 438.09 13 65 1.08 2.2 0.56 0.38 0.48 0.19 9.88 2,964 7,651 50,388 350 350 7,301 0.17 438.14 14 70 1.17 2.2 0.56 0.38 0.48 0.19 9.88 2,964 10,264 50,622 352 352 9,913 0.23 438.19 15 75 1.25 2.2 0.56 0.38 0.48 0.19 9.88 2,964 12,877 50,857 353 353 12,524 0.29 438.24 16 80 1.33 2.0 0.51 0.38 0.44 0.14 7.21 2,162 14,685 51,020 354 354 14,331 0.33 438.28 17 85 1.42 2.6 0.67 0.38 0.57 0.29 15.23 4,568 18,899 51,398 357 357 18,542 0.43 438.36 18 90 1.50 2.7 0.69 0.38 0.59 0.32 16.56 4,969 23,511 51,813 360 360 23,151 0.53 438.45 19 95 1.58 2.4 0.62 0.38 0.52 0.24 12.55 3,766 26,917 52,119 362 362 26,556 0.61 438.51 20 100 1.67 2.7 0.69 0.38 0.59 0.32 16.56 4,969 31,525 52,533 365 365 31,160 0.72 438.60 21 105 1.75 3.3 0.85 0.38 0.72 0.47 24.59 7,376 38,535 53,163 369 369 38,166 0.88 438.73 22 110 1.83 3.1 0.80 0.38 0.68 0.42 21.91 6,573 44,740 53,721 373 373 44,367 1.02 438.85 23 115 1.92 2.9 0.74 0.38 0.63 0.37 19.24 5,771 50,138 54,206 376 376 49,761 1.14 438.96 24 120 2.00 3.0 0.77 0.38 0.65 0.40 20.57 6,172 55,934 54,708 380 380 55,554 1.28 439.06 25 125 2.08 3.1 0.80 0.38 0.68 0.42 21.91 6,573 62,127 55,236 384 384 61,744 1.42 439.17 Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 51.63 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.38 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD 26 130 2.17 4.2 1.08 0.38 0.92 0.70 36.62 10,985 72,729 56,138 390 390 72,339 1.66 439.36 27 135 2.25 5.0 1.28 0.38 1.09 0.91 47.31 14,194 86,533 57,314 398 398 86,135 1.98 439.60 28 140 2.33 3.5 0.90 0.38 0.76 0.52 27.26 8,178 94,312 57,976 403 403 93,910 2.16 439.74 29 145 2.42 6.8 1.75 0.38 1.48 1.37 71.38 21,413 115,323 59,737 415 415 114,908 2.64 440.10 30 150 2.50 7.3 1.87 0.38 1.59 1.50 78.06 23,418 138,326 61,596 428 428 137,898 3.17 440.47 31 155 2.58 8.2 2.11 0.38 1.79 1.73 90.09 27,028 164,926 63,746 443 443 164,483 3.78 440.90 32 160 2.67 5.9 1.52 0.38 1.29 1.14 59.34 17,803 182,287 65,106 452 452 181,835 4.17 441.17 33 165 2.75 2.0 0.51 0.38 0.44 0.14 7.21 2,162 183,996 65,238 453 453 183,543 4.21 441.20 34 170 2.83 1.8 0.46 0.38 0.39 0.09 4.53 1,360 184,903 65,308 454 454 184,449 4.23 441.21 35 175 2.92 1.8 0.46 0.38 0.39 0.09 4.53 1,360 185,809 65,378 454 454 185,355 4.26 441.22 36 180 3.00 0.6 0.15 0.38 0.13 0.02 1.20 361 185,716 65,370 454 454 185,262 4.25 441.22 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 202,167 cu-ft 2.14 in 401,066 cu-ft 441.22 ft 90.09 cfs 13,637 cu-ft 75.76 cf/min 1.06 in 4.57 acft 198,899 cu-ft 4.26 acft 185,355 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 51.63 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.38 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.38 0.14 0.02 1.29 388 388 49,735 345 345 43 0.00 438.00 2 10 0.17 0.6 0.20 0.38 0.17 0.03 1.55 466 508 49,746 345 345 163 0.00 438.00 3 15 0.25 0.6 0.20 0.38 0.17 0.03 1.55 466 628 49,756 346 346 283 0.01 438.01 4 20 0.33 0.6 0.20 0.38 0.17 0.03 1.55 466 748 49,767 346 346 403 0.01 438.01 5 25 0.42 0.6 0.20 0.38 0.17 0.03 1.55 466 868 49,778 346 346 522 0.01 438.01 6 30 0.50 0.7 0.23 0.38 0.20 0.03 1.81 543 1,066 49,796 346 346 720 0.02 438.01 7 35 0.58 0.7 0.23 0.38 0.20 0.03 1.81 543 1,263 49,813 346 346 917 0.02 438.02 8 40 0.67 0.7 0.23 0.38 0.20 0.03 1.81 543 1,460 49,831 346 346 1,114 0.03 438.02 9 45 0.75 0.7 0.23 0.38 0.20 0.03 1.81 543 1,657 49,849 346 346 1,311 0.03 438.03 10 50 0.83 0.7 0.23 0.38 0.20 0.03 1.81 543 1,854 49,867 346 346 1,508 0.03 438.03 11 55 0.92 0.7 0.23 0.38 0.20 0.03 1.81 543 2,051 49,884 346 346 1,705 0.04 438.03 12 60 1.00 0.8 0.26 0.38 0.23 0.04 2.07 621 2,325 49,909 347 347 1,979 0.05 438.04 13 65 1.08 0.8 0.26 0.38 0.23 0.04 2.07 621 2,599 49,934 347 347 2,253 0.05 438.04 14 70 1.17 0.8 0.26 0.38 0.23 0.04 2.07 621 2,873 49,958 347 347 2,526 0.06 438.05 15 75 1.25 0.8 0.26 0.38 0.23 0.04 2.07 621 3,147 49,983 347 347 2,800 0.06 438.05 16 80 1.33 0.8 0.26 0.38 0.23 0.04 2.07 621 3,421 50,007 347 347 3,073 0.07 438.06 17 85 1.42 0.8 0.26 0.38 0.23 0.04 2.07 621 3,694 50,032 347 347 3,347 0.08 438.06 18 90 1.50 0.8 0.26 0.38 0.23 0.04 2.07 621 3,967 50,057 348 348 3,620 0.08 438.07 19 95 1.58 0.8 0.26 0.38 0.23 0.04 2.07 621 4,241 50,081 348 348 3,893 0.09 438.07 20 100 1.67 0.8 0.26 0.38 0.23 0.04 2.07 621 4,513 50,106 348 348 4,165 0.10 438.08 21 105 1.75 0.8 0.26 0.38 0.23 0.04 2.07 621 4,786 50,130 348 348 4,438 0.10 438.09 22 110 1.83 0.8 0.26 0.38 0.23 0.04 2.07 621 5,059 50,155 348 348 4,711 0.11 438.09 23 115 1.92 0.8 0.26 0.38 0.23 0.04 2.07 621 5,331 50,179 348 348 4,983 0.11 438.10 24 120 2.00 0.9 0.30 0.38 0.25 0.04 2.33 698 5,681 50,211 349 349 5,332 0.12 438.10 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 51.63 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.38 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.38 0.23 0.04 2.07 621 5,953 50,235 349 349 5,604 0.13 438.11 26 130 2.17 0.9 0.30 0.38 0.25 0.04 2.33 698 6,303 50,266 349 349 5,953 0.14 438.11 27 135 2.25 0.9 0.30 0.38 0.25 0.04 2.33 698 6,652 50,298 349 349 6,302 0.14 438.12 28 140 2.33 0.9 0.30 0.38 0.25 0.04 2.33 698 7,001 50,329 350 350 6,651 0.15 438.13 29 145 2.42 0.9 0.30 0.38 0.25 0.04 2.33 698 7,350 50,361 350 350 7,000 0.16 438.13 30 150 2.50 0.9 0.30 0.38 0.25 0.04 2.33 698 7,698 50,392 350 350 7,348 0.17 438.14 31 155 2.58 0.9 0.30 0.38 0.25 0.04 2.33 698 8,047 50,423 350 350 7,696 0.18 438.15 32 160 2.67 0.9 0.30 0.38 0.25 0.04 2.33 698 8,395 50,454 350 350 8,044 0.18 438.15 33 165 2.75 1.0 0.33 0.38 0.28 0.05 2.59 776 8,820 50,493 351 351 8,470 0.19 438.16 34 170 2.83 1.0 0.33 0.38 0.28 0.05 2.59 776 9,245 50,531 351 351 8,895 0.20 438.17 35 175 2.92 1.0 0.33 0.38 0.28 0.05 2.59 776 9,670 50,569 351 351 9,319 0.21 438.18 36 180 3.00 1.0 0.33 0.38 0.28 0.05 2.59 776 10,095 50,607 351 351 9,744 0.22 438.19 37 185 3.08 1.0 0.33 0.38 0.28 0.05 2.59 776 10,520 50,645 352 352 10,168 0.23 438.20 38 190 3.17 1.1 0.36 0.38 0.31 0.05 2.84 853 11,021 50,690 352 352 10,669 0.24 438.21 39 195 3.25 1.1 0.36 0.38 0.31 0.05 2.84 853 11,523 50,736 352 352 11,171 0.26 438.21 40 200 3.33 1.1 0.36 0.38 0.31 0.05 2.84 853 12,024 50,781 353 353 11,671 0.27 438.22 41 205 3.42 1.2 0.40 0.38 0.34 0.02 1.16 348 12,019 50,780 353 353 11,666 0.27 438.22 42 210 3.50 1.3 0.43 0.38 0.37 0.06 2.88 865 12,531 50,826 353 353 12,178 0.28 438.23 43 215 3.58 1.4 0.46 0.38 0.39 0.09 4.61 1,382 13,560 50,919 354 354 13,207 0.30 438.25 44 220 3.67 1.4 0.46 0.38 0.39 0.09 4.61 1,382 14,589 51,011 354 354 14,234 0.33 438.27 45 225 3.75 1.5 0.50 0.38 0.42 0.12 6.33 1,899 16,134 51,150 355 355 15,778 0.36 438.30 46 230 3.83 1.5 0.50 0.38 0.42 0.12 6.33 1,899 17,678 51,289 356 356 17,322 0.40 438.33 47 235 3.92 1.6 0.53 0.38 0.45 0.15 8.06 2,417 19,738 51,474 357 357 19,381 0.44 438.37 48 240 4.00 1.6 0.53 0.38 0.45 0.15 8.06 2,417 21,797 51,659 359 359 21,439 0.49 438.41 49 245 4.08 1.7 0.56 0.38 0.48 0.19 9.78 2,934 24,372 51,890 360 360 24,012 0.55 438.46 50 250 4.17 1.8 0.60 0.38 0.51 0.22 11.50 3,451 27,463 52,168 362 362 27,101 0.62 438.52 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 51.63 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 3.99 Maxwell Drywells UNIT TIME-PERCENT OF LAG 125.3 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.38 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.38 0.53 0.25 13.23 3,968 31,069 52,492 365 365 30,705 0.70 438.59 52 260 4.33 2.0 0.66 0.38 0.56 0.29 14.95 4,486 35,190 52,863 367 367 34,823 0.80 438.67 53 265 4.42 2.1 0.70 0.38 0.59 0.32 16.68 5,003 39,826 53,279 370 370 39,456 0.91 438.76 54 270 4.50 2.1 0.70 0.38 0.59 0.32 16.68 5,003 44,459 53,696 373 373 44,086 1.01 438.85 55 275 4.58 2.2 0.73 0.38 0.62 0.35 18.40 5,520 49,606 54,158 376 376 49,230 1.13 438.95 56 280 4.67 2.3 0.76 0.38 0.65 0.39 20.12 6,037 55,268 54,652 380 380 54,888 1.26 439.05 57 285 4.75 2.4 0.79 0.38 0.68 0.42 21.85 6,555 61,443 55,177 383 383 61,060 1.40 439.16 58 290 4.83 2.4 0.79 0.38 0.68 0.42 21.85 6,555 67,614 55,703 387 387 67,228 1.54 439.27 59 295 4.92 2.5 0.83 0.38 0.70 0.45 23.57 7,072 74,300 56,272 391 391 73,909 1.70 439.39 60 300 5.00 2.6 0.86 0.38 0.73 0.49 25.30 7,589 81,498 56,885 395 395 81,103 1.86 439.51 61 305 5.08 3.1 1.03 0.38 0.87 0.65 33.92 10,176 91,278 57,718 401 401 90,878 2.09 439.68 62 310 5.17 3.6 1.19 0.38 1.01 0.82 42.54 12,762 103,639 58,770 408 408 103,231 2.37 439.90 63 315 5.25 3.9 1.29 0.38 1.10 0.92 47.71 14,314 117,545 59,916 416 416 117,129 2.69 440.14 64 320 5.33 4.2 1.39 0.38 1.18 1.02 52.88 15,865 132,994 61,165 425 425 132,570 3.04 440.39 65 325 5.42 4.7 1.56 0.38 1.32 1.18 61.51 18,452 151,021 62,622 435 435 150,586 3.46 440.68 66 330 5.50 5.6 1.85 0.38 1.58 1.48 77.02 23,107 173,693 64,443 448 448 173,246 3.98 441.04 67 335 5.58 1.9 0.63 0.38 0.53 0.25 13.23 3,968 177,214 64,715 449 449 176,765 4.06 441.09 68 340 5.67 0.9 0.30 0.38 0.25 0.04 2.33 698 177,463 64,734 450 450 177,014 4.06 441.10 69 345 5.75 0.6 0.20 0.38 0.17 0.03 1.55 466 177,479 64,735 450 450 177,030 4.06 441.10 70 350 5.83 0.5 0.17 0.38 0.14 0.02 1.29 388 177,418 64,730 450 450 176,968 4.06 441.10 71 355 5.92 0.3 0.10 0.38 0.08 0.01 0.78 233 177,201 64,714 449 449 176,751 4.06 441.09 72 360 6.00 0.2 0.07 0.38 0.06 0.01 0.52 155 176,907 64,691 449 449 176,457 4.05 441.09 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 517,263 cu-ft 2.76 in 314,294 cu-ft 441.10 ft 77.02 cfs 73.64 cf/min 26,512 cu-ft 1.08 in 4.66 acft 202,969 cu-ft 4.06 acft 177,030 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 51.63 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.19 LAG TIME - MINUTES 3.99 C 0.00347 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.663 0.030 0.01 0.28 248 248 49,722 1,036 248 0 0.00 438.00 2 30 0.50 0.3 0.053 0.655 0.045 0.01 0.41 372 372 49,733 1,036 372 0 0.00 438.00 3 45 0.75 0.3 0.053 0.647 0.045 0.01 0.41 372 372 49,733 1,036 372 0 0.00 438.00 4 60 1.00 0.4 0.071 0.640 0.060 0.01 0.55 496 496 49,745 1,036 496 0 0.00 438.00 5 75 1.25 0.3 0.053 0.632 0.045 0.01 0.41 372 372 49,733 1,036 372 0 0.00 438.00 6 90 1.50 0.3 0.053 0.625 0.045 0.01 0.41 372 372 49,733 1,036 372 0 0.00 438.00 7 105 1.75 0.3 0.053 0.617 0.045 0.01 0.41 372 372 49,733 1,036 372 0 0.00 438.00 8 120 2.00 0.4 0.071 0.610 0.060 0.01 0.55 496 496 49,745 1,036 496 0 0.00 438.00 9 135 2.25 0.4 0.071 0.602 0.060 0.01 0.55 496 496 49,745 1,036 496 0 0.00 438.00 10 150 2.50 0.4 0.071 0.595 0.060 0.01 0.55 496 496 49,745 1,036 496 0 0.00 438.00 11 165 2.75 0.5 0.088 0.588 0.075 0.01 0.69 620 620 49,756 1,037 620 0 0.00 438.00 12 180 3.00 0.5 0.088 0.580 0.075 0.01 0.69 620 620 49,756 1,037 620 0 0.00 438.00 13 195 3.25 0.5 0.088 0.573 0.075 0.01 0.69 620 620 49,756 1,037 620 0 0.00 438.00 14 210 3.50 0.5 0.088 0.566 0.075 0.01 0.69 620 620 49,756 1,037 620 0 0.00 438.00 15 225 3.75 0.5 0.088 0.559 0.075 0.01 0.69 620 620 49,756 1,037 620 0 0.00 438.00 16 240 4.00 0.6 0.106 0.552 0.090 0.02 0.83 744 744 49,767 1,037 744 0 0.00 438.00 17 255 4.25 0.6 0.106 0.545 0.090 0.02 0.83 744 744 49,767 1,037 744 0 0.00 438.00 18 270 4.50 0.7 0.123 0.538 0.105 0.02 0.96 868 868 49,778 1,037 868 0 0.00 438.00 19 285 4.75 0.7 0.123 0.531 0.105 0.02 0.96 868 868 49,778 1,037 868 0 0.00 438.00 20 300 5.00 0.8 0.141 0.524 0.120 0.02 1.10 992 992 49,789 1,037 992 0 0.00 438.00 21 315 5.25 0.6 0.106 0.518 0.090 0.02 0.83 744 744 49,767 1,037 744 0 0.00 438.00 22 330 5.50 0.7 0.123 0.511 0.105 0.02 0.96 868 868 49,778 1,037 868 0 0.00 438.00 23 345 5.75 0.8 0.141 0.504 0.120 0.02 1.10 992 992 49,789 1,037 992 0 0.00 438.00 24 360 6.00 0.8 0.141 0.497 0.120 0.02 1.10 992 992 49,789 1,037 992 0 0.00 438.00 25 375 6.25 0.9 0.159 0.491 0.135 0.02 1.24 1,116 1,116 49,800 1,038 1,038 78 0.00 438.00 26 390 6.50 0.9 0.159 0.484 0.135 0.02 1.24 1,116 1,194 49,807 1,038 1,038 156 0.00 438.00 27 405 6.75 1.0 0.176 0.478 0.150 0.03 1.38 1,240 1,396 49,825 1,038 1,038 358 0.01 438.01 28 420 7.00 1.0 0.176 0.471 0.150 0.03 1.38 1,240 1,598 49,844 1,038 1,038 559 0.01 438.01 29 435 7.25 1.0 0.176 0.465 0.150 0.03 1.38 1,240 1,799 49,862 1,039 1,039 760 0.02 438.01 30 450 7.50 1.1 0.194 0.459 0.165 0.03 1.52 1,364 2,124 49,891 1,039 1,039 1,085 0.02 438.02 31 465 7.75 1.2 0.212 0.452 0.180 0.03 1.65 1,488 2,572 49,931 1,040 1,040 1,532 0.04 438.03 32 480 8.00 1.3 0.229 0.446 0.195 0.03 1.79 1,612 3,144 49,983 1,041 1,041 2,103 0.05 438.04 33 495 8.25 1.5 0.265 0.440 0.225 0.04 2.07 1,860 3,962 50,056 1,043 1,043 2,919 0.07 438.06 34 510 8.50 1.5 0.265 0.434 0.225 0.04 2.07 1,860 4,779 50,129 1,044 1,044 3,735 0.09 438.07 35 525 8.75 1.6 0.282 0.428 0.240 0.04 2.20 1,984 5,718 50,214 1,046 1,046 4,672 0.11 438.09 36 540 9.00 1.7 0.300 0.422 0.255 0.04 2.34 2,108 6,780 50,309 1,048 1,048 5,731 0.13 438.11 37 555 9.25 1.9 0.335 0.416 0.285 0.05 2.62 2,356 8,087 50,427 1,051 1,051 7,036 0.16 438.14 38 570 9.50 2.0 0.353 0.410 0.300 0.05 2.75 2,479 9,516 50,555 1,053 1,053 8,463 0.19 438.16 39 585 9.75 2.1 0.370 0.404 0.315 0.06 2.89 2,603 11,066 50,695 1,056 1,056 10,010 0.23 438.19 40 600 10.00 2.2 0.388 0.398 0.330 0.06 3.03 2,727 12,737 50,845 1,059 1,059 11,678 0.27 438.22 41 615 10.25 1.5 0.265 0.392 0.225 0.04 2.07 1,860 13,538 50,917 1,061 1,061 12,477 0.29 438.24 42 630 10.50 1.5 0.265 0.387 0.225 0.04 2.07 1,860 14,337 50,988 1,062 1,062 13,274 0.30 438.26 43 645 10.75 2.0 0.353 0.381 0.300 0.05 2.75 2,479 15,754 51,116 1,065 1,065 14,689 0.34 438.28 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 51.63 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.19 LAG TIME - MINUTES 3.99 C 0.00347 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 44 660 11.00 2.0 0.353 0.375 0.300 0.05 2.75 2,479 17,168 51,243 1,068 1,068 16,101 0.37 438.31 45 675 11.25 1.9 0.335 0.370 0.285 0.05 2.62 2,356 18,456 51,359 1,070 1,070 17,386 0.40 438.33 46 690 11.50 1.9 0.335 0.364 0.285 0.05 2.62 2,356 19,742 51,474 1,072 1,072 18,670 0.43 438.36 47 705 11.75 1.7 0.300 0.359 0.255 0.04 2.34 2,108 20,777 51,567 1,074 1,074 19,703 0.45 438.38 48 720 12.00 1.8 0.318 0.354 0.270 0.05 2.48 2,232 21,934 51,671 1,076 1,076 20,858 0.48 438.40 49 735 12.25 2.5 0.441 0.348 0.375 0.09 4.82 4,335 25,193 51,964 1,083 1,083 24,110 0.55 438.46 50 750 12.50 2.6 0.459 0.343 0.390 0.12 6.01 5,406 29,517 52,353 1,091 1,091 28,426 0.65 438.55 51 765 12.75 2.8 0.494 0.338 0.420 0.16 8.11 7,301 35,727 52,911 1,102 1,102 34,624 0.79 438.67 52 780 13.00 2.9 0.512 0.333 0.435 0.18 9.30 8,366 42,990 53,564 1,116 1,116 41,874 0.96 438.80 53 795 13.25 3.4 0.600 0.328 0.510 0.27 14.15 12,734 54,609 54,595 1,137 1,137 53,471 1.23 439.03 54 810 13.50 3.4 0.600 0.323 0.510 0.28 14.41 12,967 66,439 55,603 1,158 1,158 65,280 1.50 439.23 55 825 13.75 2.3 0.406 0.318 0.345 0.09 4.56 4,106 69,386 55,854 1,164 1,164 68,222 1.57 439.29 56 840 14.00 2.3 0.406 0.313 0.345 0.09 4.81 4,333 72,555 56,123 1,169 1,169 71,386 1.64 439.34 57 855 14.25 2.7 0.476 0.308 0.405 0.17 8.74 7,862 79,248 56,693 1,181 1,181 78,067 1.79 439.46 58 870 14.50 2.6 0.459 0.304 0.390 0.15 8.06 7,256 85,323 57,211 1,192 1,192 84,131 1.93 439.57 59 885 14.75 2.6 0.459 0.299 0.390 0.16 8.30 7,474 91,605 57,745 1,203 1,203 90,402 2.08 439.68 60 900 15.00 2.5 0.441 0.295 0.375 0.15 7.62 6,862 97,264 58,227 1,213 1,213 96,051 2.21 439.78 61 915 15.25 2.4 0.423 0.290 0.360 0.13 6.94 6,247 102,298 58,656 1,222 1,222 101,076 2.32 439.86 62 930 15.50 2.3 0.406 0.286 0.345 0.12 6.25 5,628 106,704 59,031 1,230 1,230 105,474 2.42 439.94 63 945 15.75 1.9 0.335 0.281 0.285 0.05 2.81 2,527 108,001 59,141 1,232 1,232 106,769 2.45 439.96 64 960 16.00 1.9 0.335 0.277 0.285 0.06 3.03 2,728 109,497 59,266 1,235 1,235 108,262 2.49 439.99 65 975 16.25 0.4 0.071 0.273 0.060 0.01 0.55 496 108,758 59,206 1,233 1,233 107,524 2.47 439.98 66 990 16.50 0.4 0.071 0.269 0.060 0.01 0.55 496 108,020 59,143 1,232 1,232 106,788 2.45 439.96 67 1005 16.75 0.3 0.053 0.264 0.045 0.01 0.41 372 107,160 59,070 1,231 1,231 105,930 2.43 439.95 68 1020 17.00 0.3 0.053 0.260 0.045 0.01 0.41 372 106,301 58,997 1,229 1,229 105,072 2.41 439.93 69 1035 17.25 0.5 0.088 0.257 0.075 0.01 0.69 620 105,692 58,945 1,228 1,228 104,464 2.40 439.92 70 1050 17.50 0.5 0.088 0.253 0.075 0.01 0.69 620 105,084 58,893 1,227 1,227 103,857 2.38 439.91 71 1065 17.75 0.5 0.088 0.249 0.075 0.01 0.69 620 104,477 58,841 1,226 1,226 103,251 2.37 439.90 72 1080 18.00 0.4 0.071 0.245 0.060 0.01 0.55 496 103,747 58,779 1,225 1,225 102,522 2.35 439.89 73 1095 18.25 0.4 0.071 0.242 0.060 0.01 0.55 496 103,018 58,717 1,223 1,223 101,795 2.34 439.88 74 1110 18.50 0.4 0.071 0.238 0.060 0.01 0.55 496 102,291 58,655 1,222 1,222 101,069 2.32 439.86 75 1125 18.75 0.3 0.053 0.235 0.045 0.01 0.41 372 101,441 58,583 1,220 1,220 100,220 2.30 439.85 76 1140 19.00 0.2 0.035 0.231 0.030 0.01 0.28 248 100,468 58,500 1,219 1,219 99,250 2.28 439.83 77 1155 19.25 0.3 0.053 0.228 0.045 0.01 0.41 372 99,622 58,428 1,217 1,217 98,404 2.26 439.82 78 1170 19.50 0.4 0.071 0.225 0.060 0.01 0.55 496 98,900 58,367 1,216 1,216 97,684 2.24 439.80 79 1185 19.75 0.3 0.053 0.222 0.045 0.01 0.41 372 98,056 58,295 1,214 1,214 96,842 2.22 439.79 80 1200 20.00 0.2 0.035 0.219 0.030 0.01 0.28 248 97,090 58,212 1,213 1,213 95,877 2.20 439.77 81 1215 20.25 0.3 0.053 0.216 0.045 0.01 0.41 372 96,249 58,141 1,211 1,211 95,038 2.18 439.76 82 1230 20.50 0.3 0.053 0.213 0.045 0.01 0.41 372 95,409 58,069 1,210 1,210 94,200 2.16 439.74 83 1245 20.75 0.3 0.053 0.210 0.045 0.01 0.41 372 94,572 57,998 1,208 1,208 93,363 2.14 439.73 84 1260 21.00 0.2 0.035 0.208 0.030 0.01 0.28 248 93,611 57,916 1,207 1,207 92,405 2.12 439.71 85 1275 21.25 0.3 0.053 0.205 0.045 0.01 0.41 372 92,777 57,845 1,205 1,205 91,572 2.10 439.70 86 1290 21.50 0.2 0.035 0.203 0.030 0.01 0.28 248 91,819 57,764 1,203 1,203 90,616 2.08 439.68 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 51.63 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.19 LAG TIME - MINUTES 3.99 C 0.00347 Maxwell Drywells UNIT TIME-PERCENT OF LAG 376%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 87 1305 21.75 0.3 0.053 0.201 0.045 0.01 0.41 372 90,988 57,693 1,202 1,202 89,786 2.06 439.67 88 1320 22.00 0.2 0.035 0.199 0.030 0.01 0.28 248 90,034 57,612 1,200 1,200 88,834 2.04 439.65 89 1335 22.25 0.3 0.053 0.197 0.045 0.01 0.41 372 89,206 57,541 1,199 1,199 88,007 2.02 439.63 90 1350 22.50 0.2 0.035 0.195 0.030 0.01 0.28 248 88,255 57,460 1,197 1,197 87,058 2.00 439.62 91 1365 22.75 0.2 0.035 0.193 0.030 0.01 0.28 248 87,306 57,379 1,195 1,195 86,110 1.98 439.60 92 1380 23.00 0.2 0.035 0.192 0.030 0.01 0.28 248 86,358 57,299 1,194 1,194 85,165 1.96 439.58 93 1395 23.25 0.2 0.035 0.190 0.030 0.01 0.28 248 85,412 57,218 1,192 1,192 84,220 1.93 439.57 94 1410 23.50 0.2 0.035 0.189 0.030 0.01 0.28 248 84,468 57,138 1,190 1,190 83,278 1.91 439.55 95 1425 23.75 0.2 0.035 0.188 0.030 0.01 0.28 248 83,526 57,058 1,189 1,189 82,337 1.89 439.53 96 1440 24.00 0.2 0.035 0.188 0.030 0.01 0.28 248 82,585 56,977 1,187 1,187 81,398 1.87 439.52 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 4.41 in 826,496 cu-ft 647,343 cu-ft 439.99 ft 14.41 cfs 97,755 cu-ft 67.89 cf/min 0.96 in 4.11 acft 179,153 cu-ft 2.49 acft 108,262 cu-ft Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 438 0 0 49,700 0 0 0.00 439 1 1 4,675 54,375 52,020 52,020 1.19 440 1 2 4,834 59,209 56,775 108,795 2.50 441 1 3 4,986 64,195 61,685 170,480 3.91 442 1 4 5,150 69,345 66,753 237,233 5.45 WHERE: TOTAL BASIN I BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 2 B PAVING/HARDSCAPE 5.754 D 56 0.51 1.00 9 B LANDSCAPING 5.950 D 56 0.51 0.10 3,950 ft 1,975 ft 462.3 ft ELEVATION OF CONCENTRATION POINT 442.0 ft 0.02 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 438.0 ft 21,900 sf 439.0 ft 27,300 sf 440.0 ft 31,405 sf 441.0 ft 36,785 sf 442.0 ft 41,185 sf PERCOLATION RATE (in/hr)1.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 EXISTING BASIN AMC NUMBER RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention OFF-SITE NORTH Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)61,179 90,919 117,260 187,362 SOIL LOSSES (cu-ft)11,089 32,807 61,345 128,299 EFFECTIVE RAIN (in)1.18 1.37 1.32 1.39 FLOOD VOLUME (cu-ft)50,090 58,112 55,916 59,063 (acre-ft)1.15 1.33 1.28 1.36 REQUIRED STORAGE (cu-ft)47,956 51,905 47,036 34,787 (acre-ft)1.10 1.19 1.08 0.80 FACTOR OF SAFETY 2.65 2.44 2.70 3.65 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 21.77 18.81 4.43 MAXIMUM WSEL (ft)439.80 439.93 439.77 439.35 DEPTH (ft)1.80 1.93 1.77 1.35 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days)1.0 1.1 1.5 1.5 EXISTING BASIN OFF-SITE NORTH CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 11.704 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION [3] AREA - ACRES [4] L-FEET [5] L-MILES 3950 0.748 [13] L*LCA/S^0.5 5.21 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.054 1975.00 [12] S^0.5 0.374 27.1 462.3 442 20.3 0.02 [17] 100% OF LAG-MINUTES 9.5 9.5 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.16 [16] LAG TIME-MINUTES [18] 200% OF LAG-MINUTES RAINFALL DATA 19.0 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 126,903 2.91 Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 100%0.05 5.754 0.492 0.0251 DEVELOPED 0.1000 0.0492 B 56 0.51 10%0.46 5.950 0.508 0.2359 DEVELOPED 0.8200 0.4169 SUM 11.704 SUM 0.2610 0.4660 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.130504486 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00242 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00242 0.13 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.2610 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II (24-(T/60))^1.55 + LAND USE PAVING/HARDSCAPE LANDSCAPING Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 11.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 9.48 Maxwell Drywells UNIT TIME-PERCENT OF LAG 52.7 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.26 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.26 0.53 0.36 4.26 1,278 1,278 22,181 154 154 1,124 0.03 438.05 2 10 0.17 4.2 0.73 0.26 0.62 0.46 5.48 1,645 2,770 22,509 156 156 2,613 0.06 438.11 3 15 0.25 4.4 0.76 0.26 0.65 0.50 5.89 1,768 4,381 22,864 159 159 4,222 0.10 438.17 4 20 0.33 4.6 0.79 0.26 0.68 0.53 6.30 1,890 6,113 23,245 161 161 5,951 0.14 438.24 5 25 0.42 5.0 0.86 0.26 0.73 0.60 7.12 2,135 8,086 23,679 164 164 7,922 0.18 438.32 6 30 0.50 5.6 0.97 0.26 0.82 0.71 8.34 2,502 10,424 24,193 168 168 10,256 0.24 438.42 7 35 0.58 6.4 1.11 0.26 0.94 0.84 9.97 2,991 13,247 24,814 172 172 13,075 0.30 438.53 8 40 0.67 8.1 1.40 0.26 1.19 1.14 13.44 4,031 17,106 25,663 178 178 16,928 0.39 438.69 9 45 0.75 13.1 2.26 0.26 1.92 2.00 23.63 7,090 24,018 27,183 189 189 23,830 0.55 438.97 10 50 0.83 34.5 5.96 0.26 5.07 5.70 67.28 20,183 44,012 30,024 208 208 43,804 1.01 439.66 11 55 0.92 6.7 1.16 0.26 0.98 0.90 10.58 3,175 46,979 30,439 211 211 46,767 1.07 439.76 12 60 1.00 3.8 0.66 0.26 0.56 0.40 4.67 1,401 48,168 30,606 213 213 47,956 1.10 439.80 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 61,179 cu-ft SOIL LOSSES 11,089 cu-ft EFFECTIVE RAIN 1.18 in FLOOD VOLUME 1.15 acft FLOOD VOLUME 50,090 cu-ft REQUIRED STORAGE 1.10 REQUIRED STORAGE 47,956 cu-ft MAX WSEL 439.80 ft PEAK FLOW RATE 67.28 cfs TOTAL BASIN LOSSES 2,135 cu-ft AVERAGE PERCOLATION RATE 35.58 cf/min CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 11.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 9.48 Maxwell Drywells UNIT TIME-PERCENT OF LAG 52.7 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.26 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.26 0.28 0.07 0.86 258 258 21,957 152 152 105 0.00 438.00 2 10 0.17 1.3 0.33 0.26 0.28 0.07 0.86 258 363 21,980 153 153 211 0.00 438.01 3 15 0.25 1.1 0.28 0.26 0.24 0.02 0.25 76 287 21,963 153 153 134 0.00 438.01 4 20 0.33 1.5 0.39 0.26 0.33 0.12 1.47 440 574 22,026 153 153 421 0.01 438.02 5 25 0.42 1.5 0.39 0.26 0.33 0.12 1.47 440 861 22,089 153 153 707 0.02 438.03 6 30 0.50 1.8 0.46 0.26 0.39 0.20 2.37 712 1,420 22,212 154 154 1,265 0.03 438.05 7 35 0.58 1.5 0.39 0.26 0.33 0.12 1.47 440 1,705 22,275 155 155 1,550 0.04 438.06 8 40 0.67 1.8 0.46 0.26 0.39 0.20 2.37 712 2,263 22,398 156 156 2,107 0.05 438.09 9 45 0.75 1.8 0.46 0.26 0.39 0.20 2.37 712 2,820 22,520 156 156 2,663 0.06 438.11 10 50 0.83 1.5 0.39 0.26 0.33 0.12 1.47 440 3,103 22,583 157 157 2,946 0.07 438.12 11 55 0.92 1.6 0.41 0.26 0.35 0.15 1.77 531 3,477 22,665 157 157 3,319 0.08 438.14 12 60 1.00 1.8 0.46 0.26 0.39 0.20 2.37 712 4,032 22,787 158 158 3,874 0.09 438.16 13 65 1.08 2.2 0.56 0.26 0.48 0.30 3.59 1,076 4,950 22,989 160 160 4,790 0.11 438.20 14 70 1.17 2.2 0.56 0.26 0.48 0.30 3.59 1,076 5,866 23,190 161 161 5,705 0.13 438.23 15 75 1.25 2.2 0.56 0.26 0.48 0.30 3.59 1,076 6,781 23,392 162 162 6,619 0.15 438.27 16 80 1.33 2.0 0.51 0.26 0.44 0.25 2.98 894 7,513 23,553 164 164 7,350 0.17 438.30 17 85 1.42 2.6 0.67 0.26 0.57 0.41 4.80 1,440 8,789 23,833 166 166 8,624 0.20 438.35 18 90 1.50 2.7 0.69 0.26 0.59 0.43 5.10 1,531 10,155 24,134 168 168 9,987 0.23 438.41 19 95 1.58 2.4 0.62 0.26 0.52 0.36 4.19 1,258 11,245 24,373 169 169 11,076 0.25 438.45 20 100 1.67 2.7 0.69 0.26 0.59 0.43 5.10 1,531 12,606 24,673 171 171 12,435 0.29 438.51 21 105 1.75 3.3 0.85 0.26 0.72 0.59 6.92 2,076 14,511 25,092 174 174 14,337 0.33 438.58 22 110 1.83 3.1 0.80 0.26 0.68 0.54 6.31 1,894 16,232 25,470 177 177 16,055 0.37 438.65 23 115 1.92 2.9 0.74 0.26 0.63 0.48 5.71 1,713 17,767 25,808 179 179 17,588 0.40 438.72 24 120 2.00 3.0 0.77 0.26 0.65 0.51 6.01 1,803 19,391 26,165 182 182 19,210 0.44 438.78 25 125 2.08 3.1 0.80 0.26 0.68 0.54 6.31 1,894 21,104 26,542 184 184 20,920 0.48 438.85 Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 11.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 9.48 Maxwell Drywells UNIT TIME-PERCENT OF LAG 52.7 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.26 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD 26 130 2.17 4.2 1.08 0.26 0.92 0.82 9.65 2,895 23,814 27,138 188 188 23,626 0.54 438.96 27 135 2.25 5.0 1.28 0.26 1.09 1.02 12.07 3,622 27,248 27,678 192 192 27,056 0.62 439.09 28 140 2.33 3.5 0.90 0.26 0.76 0.64 7.53 2,258 29,314 27,967 194 194 29,119 0.67 439.16 29 145 2.42 6.8 1.75 0.26 1.48 1.49 17.53 5,258 34,378 28,676 199 199 34,179 0.78 439.33 30 150 2.50 7.3 1.87 0.26 1.59 1.61 19.04 5,713 39,892 29,447 204 204 39,687 0.91 439.52 31 155 2.58 8.2 2.11 0.26 1.79 1.84 21.77 6,531 46,219 30,333 211 211 46,008 1.06 439.73 32 160 2.67 5.9 1.52 0.26 1.29 1.25 14.80 4,440 50,448 30,925 215 215 50,233 1.15 439.88 33 165 2.75 2.0 0.51 0.26 0.44 0.25 2.98 894 51,128 31,020 215 215 50,912 1.17 439.90 34 170 2.83 1.8 0.46 0.26 0.39 0.20 2.37 712 51,625 31,089 216 216 51,409 1.18 439.92 35 175 2.92 1.8 0.46 0.26 0.39 0.20 2.37 712 52,121 31,159 216 216 51,905 1.19 439.93 36 180 3.00 0.6 0.15 0.26 0.13 0.02 0.27 82 51,987 31,140 216 216 51,770 1.19 439.93 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 32,807 cu-ft 2.14 in 90,919 cu-ft 439.93 ft 21.77 cfs 6,342 cu-ft 35.23 cf/min 1.37 in 1.33 acft 58,112 cu-ft 1.19 acft 51,905 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 11.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 9.48 Maxwell Drywells UNIT TIME-PERCENT OF LAG 52.7 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.26 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.26 0.14 0.02 0.29 88 88 21,919 152 88 0 0.00 438.00 2 10 0.17 0.6 0.20 0.26 0.17 0.03 0.35 106 106 21,923 152 106 0 0.00 438.00 3 15 0.25 0.6 0.20 0.26 0.17 0.03 0.35 106 106 21,923 152 106 0 0.00 438.00 4 20 0.33 0.6 0.20 0.26 0.17 0.03 0.35 106 106 21,923 152 106 0 0.00 438.00 5 25 0.42 0.6 0.20 0.26 0.17 0.03 0.35 106 106 21,923 152 106 0 0.00 438.00 6 30 0.50 0.7 0.23 0.26 0.20 0.03 0.41 123 123 21,927 152 123 0 0.00 438.00 7 35 0.58 0.7 0.23 0.26 0.20 0.03 0.41 123 123 21,927 152 123 0 0.00 438.00 8 40 0.67 0.7 0.23 0.26 0.20 0.03 0.41 123 123 21,927 152 123 0 0.00 438.00 9 45 0.75 0.7 0.23 0.26 0.20 0.03 0.41 123 123 21,927 152 123 0 0.00 438.00 10 50 0.83 0.7 0.23 0.26 0.20 0.03 0.41 123 123 21,927 152 123 0 0.00 438.00 11 55 0.92 0.7 0.23 0.26 0.20 0.03 0.41 123 123 21,927 152 123 0 0.00 438.00 12 60 1.00 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 13 65 1.08 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 14 70 1.17 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 15 75 1.25 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 16 80 1.33 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 17 85 1.42 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 18 90 1.50 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 19 95 1.58 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 20 100 1.67 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 21 105 1.75 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 22 110 1.83 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 23 115 1.92 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 24 120 2.00 0.9 0.30 0.26 0.25 0.04 0.44 131 131 21,929 152 131 0 0.00 438.00 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 11.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 9.48 Maxwell Drywells UNIT TIME-PERCENT OF LAG 52.7 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.26 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.26 0.23 0.00 0.05 14 14 21,903 152 14 0 0.00 438.00 26 130 2.17 0.9 0.30 0.26 0.25 0.04 0.44 131 131 21,929 152 131 0 0.00 438.00 27 135 2.25 0.9 0.30 0.26 0.25 0.04 0.44 131 131 21,929 152 131 0 0.00 438.00 28 140 2.33 0.9 0.30 0.26 0.25 0.04 0.44 131 131 21,929 152 131 0 0.00 438.00 29 145 2.42 0.9 0.30 0.26 0.25 0.04 0.44 131 131 21,929 152 131 0 0.00 438.00 30 150 2.50 0.9 0.30 0.26 0.25 0.04 0.44 131 131 21,929 152 131 0 0.00 438.00 31 155 2.58 0.9 0.30 0.26 0.25 0.04 0.44 131 131 21,929 152 131 0 0.00 438.00 32 160 2.67 0.9 0.30 0.26 0.25 0.04 0.44 131 131 21,929 152 131 0 0.00 438.00 33 165 2.75 1.0 0.33 0.26 0.28 0.07 0.83 249 249 21,955 152 152 96 0.00 438.00 34 170 2.83 1.0 0.33 0.26 0.28 0.07 0.83 249 345 21,976 153 153 192 0.00 438.01 35 175 2.92 1.0 0.33 0.26 0.28 0.07 0.83 249 440 21,997 153 153 288 0.01 438.01 36 180 3.00 1.0 0.33 0.26 0.28 0.07 0.83 249 536 22,018 153 153 383 0.01 438.02 37 185 3.08 1.0 0.33 0.26 0.28 0.07 0.83 249 632 22,039 153 153 479 0.01 438.02 38 190 3.17 1.1 0.36 0.26 0.31 0.10 1.22 366 845 22,086 153 153 691 0.02 438.03 39 195 3.25 1.1 0.36 0.26 0.31 0.10 1.22 366 1,057 22,132 154 154 903 0.02 438.04 40 200 3.33 1.1 0.36 0.26 0.31 0.10 1.22 366 1,269 22,179 154 154 1,115 0.03 438.05 41 205 3.42 1.2 0.40 0.26 0.34 0.14 1.61 483 1,598 22,251 155 155 1,443 0.03 438.06 42 210 3.50 1.3 0.43 0.26 0.37 0.17 2.00 600 2,044 22,350 155 155 1,889 0.04 438.08 43 215 3.58 1.4 0.46 0.26 0.39 0.20 2.39 718 2,606 22,473 156 156 2,450 0.06 438.10 44 220 3.67 1.4 0.46 0.26 0.39 0.20 2.39 718 3,168 22,597 157 157 3,011 0.07 438.12 45 225 3.75 1.5 0.50 0.26 0.42 0.24 2.78 835 3,846 22,746 158 158 3,688 0.08 438.15 46 230 3.83 1.5 0.50 0.26 0.42 0.24 2.78 835 4,522 22,895 159 159 4,363 0.10 438.18 47 235 3.92 1.6 0.53 0.26 0.45 0.27 3.17 952 5,315 23,069 160 160 5,155 0.12 438.21 48 240 4.00 1.6 0.53 0.26 0.45 0.27 3.17 952 6,107 23,243 161 161 5,946 0.14 438.24 49 245 4.08 1.7 0.56 0.26 0.48 0.30 3.56 1,069 7,015 23,443 163 163 6,852 0.16 438.28 50 250 4.17 1.8 0.60 0.26 0.51 0.34 3.96 1,187 8,039 23,668 164 164 7,875 0.18 438.32 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 11.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 9.48 Maxwell Drywells UNIT TIME-PERCENT OF LAG 52.7 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.26 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.26 0.53 0.37 4.35 1,304 9,179 23,919 166 166 9,012 0.21 438.37 52 260 4.33 2.0 0.66 0.26 0.56 0.40 4.74 1,421 10,434 24,195 168 168 10,266 0.24 438.42 53 265 4.42 2.1 0.70 0.26 0.59 0.43 5.13 1,538 11,804 24,496 170 170 11,634 0.27 438.47 54 270 4.50 2.1 0.70 0.26 0.59 0.43 5.13 1,538 13,172 24,797 172 172 13,000 0.30 438.53 55 275 4.58 2.2 0.73 0.26 0.62 0.47 5.52 1,656 14,656 25,124 174 174 14,481 0.33 438.59 56 280 4.67 2.3 0.76 0.26 0.65 0.50 5.91 1,773 16,254 25,475 177 177 16,077 0.37 438.65 57 285 4.75 2.4 0.79 0.26 0.68 0.53 6.30 1,890 17,967 25,852 180 180 17,788 0.41 438.72 58 290 4.83 2.4 0.79 0.26 0.68 0.53 6.30 1,890 19,678 26,228 182 182 19,496 0.45 438.79 59 295 4.92 2.5 0.83 0.26 0.70 0.57 6.69 2,007 21,503 26,630 185 185 21,318 0.49 438.87 60 300 5.00 2.6 0.86 0.26 0.73 0.60 7.08 2,125 23,443 27,056 188 188 23,255 0.53 438.95 61 305 5.08 3.1 1.03 0.26 0.87 0.77 9.04 2,711 25,966 27,498 191 191 25,775 0.59 439.04 62 310 5.17 3.6 1.19 0.26 1.01 0.93 10.99 3,297 29,072 27,933 194 194 28,878 0.66 439.15 63 315 5.25 3.9 1.29 0.26 1.10 1.03 12.16 3,649 32,527 28,417 197 197 32,330 0.74 439.27 64 320 5.33 4.2 1.39 0.26 1.18 1.13 13.34 4,001 36,331 28,949 201 201 36,130 0.83 439.39 65 325 5.42 4.7 1.56 0.26 1.32 1.30 15.29 4,587 40,717 29,563 205 205 40,512 0.93 439.54 66 330 5.50 5.6 1.85 0.26 1.58 1.59 18.81 5,642 46,154 30,324 211 211 45,944 1.05 439.73 67 335 5.58 1.9 0.63 0.26 0.53 0.37 4.35 1,304 47,247 30,477 212 212 47,036 1.08 439.77 68 340 5.67 0.9 0.30 0.26 0.25 0.04 0.44 131 47,167 30,466 212 212 46,956 1.08 439.76 69 345 5.75 0.6 0.20 0.26 0.17 0.03 0.35 106 47,061 30,451 211 211 46,850 1.08 439.76 70 350 5.83 0.5 0.17 0.26 0.14 0.02 0.29 88 46,938 30,433 211 211 46,726 1.07 439.76 71 355 5.92 0.3 0.10 0.26 0.08 0.01 0.18 53 46,779 30,411 211 211 46,568 1.07 439.75 72 360 6.00 0.2 0.07 0.26 0.06 0.01 0.12 35 46,603 30,387 211 211 46,392 1.07 439.74 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 117,260 cu-ft 2.76 in 61,345 cu-ft 439.77 ft 18.81 cfs 26.45 cf/min 9,524 cu-ft 1.32 in 1.28 acft 55,916 cu-ft 1.08 acft 47,036 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 11.70 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.13 LAG TIME - MINUTES 9.48 C 0.00242 Maxwell Drywells UNIT TIME-PERCENT OF LAG 158%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.461 0.030 0.01 0.06 56 56 21,912 457 56 0 0.00 438.00 2 30 0.50 0.3 0.053 0.456 0.045 0.01 0.09 84 84 21,919 457 84 0 0.00 438.00 3 45 0.75 0.3 0.053 0.450 0.045 0.01 0.09 84 84 21,919 457 84 0 0.00 438.00 4 60 1.00 0.4 0.071 0.445 0.060 0.01 0.12 112 112 21,925 457 112 0 0.00 438.00 5 75 1.25 0.3 0.053 0.440 0.045 0.01 0.09 84 84 21,919 457 84 0 0.00 438.00 6 90 1.50 0.3 0.053 0.434 0.045 0.01 0.09 84 84 21,919 457 84 0 0.00 438.00 7 105 1.75 0.3 0.053 0.429 0.045 0.01 0.09 84 84 21,919 457 84 0 0.00 438.00 8 120 2.00 0.4 0.071 0.424 0.060 0.01 0.12 112 112 21,925 457 112 0 0.00 438.00 9 135 2.25 0.4 0.071 0.419 0.060 0.01 0.12 112 112 21,925 457 112 0 0.00 438.00 10 150 2.50 0.4 0.071 0.414 0.060 0.01 0.12 112 112 21,925 457 112 0 0.00 438.00 11 165 2.75 0.5 0.088 0.409 0.075 0.01 0.16 141 141 21,931 457 141 0 0.00 438.00 12 180 3.00 0.5 0.088 0.404 0.075 0.01 0.16 141 141 21,931 457 141 0 0.00 438.00 13 195 3.25 0.5 0.088 0.399 0.075 0.01 0.16 141 141 21,931 457 141 0 0.00 438.00 14 210 3.50 0.5 0.088 0.394 0.075 0.01 0.16 141 141 21,931 457 141 0 0.00 438.00 15 225 3.75 0.5 0.088 0.389 0.075 0.01 0.16 141 141 21,931 457 141 0 0.00 438.00 16 240 4.00 0.6 0.106 0.384 0.090 0.02 0.19 169 169 21,937 457 169 0 0.00 438.00 17 255 4.25 0.6 0.106 0.379 0.090 0.02 0.19 169 169 21,937 457 169 0 0.00 438.00 18 270 4.50 0.7 0.123 0.374 0.105 0.02 0.22 197 197 21,943 457 197 0 0.00 438.00 19 285 4.75 0.7 0.123 0.370 0.105 0.02 0.22 197 197 21,943 457 197 0 0.00 438.00 20 300 5.00 0.8 0.141 0.365 0.120 0.02 0.25 225 225 21,949 457 225 0 0.00 438.00 21 315 5.25 0.6 0.106 0.360 0.090 0.02 0.19 169 169 21,937 457 169 0 0.00 438.00 22 330 5.50 0.7 0.123 0.355 0.105 0.02 0.22 197 197 21,943 457 197 0 0.00 438.00 23 345 5.75 0.8 0.141 0.351 0.120 0.02 0.25 225 225 21,949 457 225 0 0.00 438.00 24 360 6.00 0.8 0.141 0.346 0.120 0.02 0.25 225 225 21,949 457 225 0 0.00 438.00 25 375 6.25 0.9 0.159 0.341 0.135 0.02 0.28 253 253 21,956 457 253 0 0.00 438.00 26 390 6.50 0.9 0.159 0.337 0.135 0.02 0.28 253 253 21,956 457 253 0 0.00 438.00 27 405 6.75 1.0 0.176 0.332 0.150 0.03 0.31 281 281 21,962 458 281 0 0.00 438.00 28 420 7.00 1.0 0.176 0.328 0.150 0.03 0.31 281 281 21,962 458 281 0 0.00 438.00 29 435 7.25 1.0 0.176 0.323 0.150 0.03 0.31 281 281 21,962 458 281 0 0.00 438.00 30 450 7.50 1.1 0.194 0.319 0.165 0.03 0.34 309 309 21,968 458 309 0 0.00 438.00 31 465 7.75 1.2 0.212 0.315 0.180 0.03 0.37 337 337 21,974 458 337 0 0.00 438.00 32 480 8.00 1.3 0.229 0.310 0.195 0.03 0.41 365 365 21,980 458 365 0 0.00 438.00 33 495 8.25 1.5 0.265 0.306 0.225 0.04 0.47 422 422 21,993 458 422 0 0.00 438.00 34 510 8.50 1.5 0.265 0.302 0.225 0.04 0.47 422 422 21,993 458 422 0 0.00 438.00 35 525 8.75 1.6 0.282 0.298 0.240 0.04 0.50 450 450 21,999 458 450 0 0.00 438.00 36 540 9.00 1.7 0.300 0.293 0.255 0.01 0.08 69 69 21,915 457 69 0 0.00 438.00 37 555 9.25 1.9 0.335 0.289 0.285 0.05 0.54 488 488 22,007 458 458 30 0.00 438.00 38 570 9.50 2.0 0.353 0.285 0.300 0.07 0.80 719 749 22,065 460 460 289 0.01 438.01 39 585 9.75 2.1 0.370 0.281 0.315 0.09 1.06 950 1,239 22,173 462 462 777 0.02 438.03 40 600 10.00 2.2 0.388 0.277 0.330 0.11 1.31 1,180 1,958 22,331 465 465 1,492 0.03 438.06 41 615 10.25 1.5 0.265 0.273 0.225 0.04 0.47 422 1,914 22,321 465 465 1,449 0.03 438.06 42 630 10.50 1.5 0.265 0.269 0.225 0.04 0.47 422 1,871 22,311 465 465 1,406 0.03 438.06 43 645 10.75 2.0 0.353 0.265 0.300 0.09 1.04 932 2,337 22,414 467 467 1,870 0.04 438.08 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 11.70 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.13 LAG TIME - MINUTES 9.48 C 0.00242 Maxwell Drywells UNIT TIME-PERCENT OF LAG 158%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 44 660 11.00 2.0 0.353 0.261 0.300 0.09 1.08 973 2,843 22,525 469 469 2,374 0.05 438.10 45 675 11.25 1.9 0.335 0.257 0.285 0.08 0.92 826 3,200 22,604 471 471 2,729 0.06 438.11 46 690 11.50 1.9 0.335 0.254 0.285 0.08 0.96 867 3,596 22,691 473 473 3,123 0.07 438.13 47 705 11.75 1.7 0.300 0.250 0.255 0.05 0.59 532 3,655 22,704 473 473 3,182 0.07 438.13 48 720 12.00 1.8 0.318 0.246 0.270 0.07 0.84 759 3,941 22,767 474 474 3,466 0.08 438.14 49 735 12.25 2.5 0.441 0.242 0.375 0.20 2.34 2,109 5,575 23,126 482 482 5,094 0.12 438.21 50 750 12.50 2.6 0.459 0.239 0.390 0.22 2.59 2,335 7,429 23,534 490 490 6,938 0.16 438.28 51 765 12.75 2.8 0.494 0.235 0.420 0.26 3.05 2,748 9,686 24,031 501 501 9,186 0.21 438.37 52 780 13.00 2.9 0.512 0.232 0.435 0.28 3.30 2,973 12,159 24,574 512 512 11,647 0.27 438.47 53 795 13.25 3.4 0.600 0.228 0.510 0.37 4.39 3,947 15,593 25,330 528 528 15,066 0.35 438.61 54 810 13.50 3.4 0.600 0.225 0.510 0.38 4.43 3,984 19,049 26,090 544 544 18,506 0.42 438.75 55 825 13.75 2.3 0.406 0.221 0.345 0.18 2.18 1,959 20,465 26,401 550 550 19,915 0.46 438.81 56 840 14.00 2.3 0.406 0.218 0.345 0.19 2.22 1,995 21,909 26,719 557 557 21,353 0.49 438.87 57 855 14.25 2.7 0.476 0.215 0.405 0.26 3.09 2,779 24,132 27,208 567 567 23,565 0.54 438.96 58 870 14.50 2.6 0.459 0.211 0.390 0.25 2.92 2,627 26,192 27,530 574 574 25,619 0.59 439.04 59 885 14.75 2.6 0.459 0.208 0.390 0.25 2.96 2,661 28,280 27,822 580 580 27,700 0.64 439.11 60 900 15.00 2.5 0.441 0.205 0.375 0.24 2.79 2,508 30,208 28,092 585 585 29,623 0.68 439.17 61 915 15.25 2.4 0.423 0.202 0.360 0.22 2.62 2,354 31,976 28,339 590 590 31,386 0.72 439.23 62 930 15.50 2.3 0.406 0.199 0.345 0.21 2.44 2,199 33,585 28,565 595 595 32,990 0.76 439.29 63 945 15.75 1.9 0.335 0.196 0.285 0.14 1.65 1,482 34,472 28,689 598 598 33,874 0.78 439.32 64 960 16.00 1.9 0.335 0.193 0.285 0.14 1.68 1,514 35,388 28,817 600 600 34,787 0.80 439.35 65 975 16.25 0.4 0.071 0.190 0.060 0.01 0.12 112 34,900 28,749 599 599 34,301 0.79 439.33 66 990 16.50 0.4 0.071 0.187 0.060 0.01 0.12 112 34,413 28,680 598 598 33,816 0.78 439.32 67 1005 16.75 0.3 0.053 0.184 0.045 0.01 0.09 84 33,900 28,609 596 596 33,304 0.76 439.30 68 1020 17.00 0.3 0.053 0.181 0.045 0.01 0.09 84 33,388 28,537 595 595 32,794 0.75 439.28 69 1035 17.25 0.5 0.088 0.178 0.075 0.01 0.16 141 32,934 28,473 593 593 32,341 0.74 439.27 70 1050 17.50 0.5 0.088 0.176 0.075 0.01 0.16 141 32,482 28,410 592 592 31,890 0.73 439.25 71 1065 17.75 0.5 0.088 0.173 0.075 0.01 0.16 141 32,030 28,347 591 591 31,440 0.72 439.23 72 1080 18.00 0.4 0.071 0.171 0.060 0.01 0.12 112 31,552 28,280 589 589 30,963 0.71 439.22 73 1095 18.25 0.4 0.071 0.168 0.060 0.01 0.12 112 31,075 28,213 588 588 30,487 0.70 439.20 74 1110 18.50 0.4 0.071 0.166 0.060 0.01 0.12 112 30,600 28,147 586 586 30,014 0.69 439.19 75 1125 18.75 0.3 0.053 0.163 0.045 0.01 0.09 84 30,098 28,076 585 585 29,513 0.68 439.17 76 1140 19.00 0.2 0.035 0.161 0.030 0.01 0.06 56 29,569 28,002 583 583 28,986 0.67 439.15 77 1155 19.25 0.3 0.053 0.159 0.045 0.01 0.09 84 29,070 27,933 582 582 28,488 0.65 439.13 78 1170 19.50 0.4 0.071 0.156 0.060 0.01 0.12 112 28,601 27,867 581 581 28,020 0.64 439.12 79 1185 19.75 0.3 0.053 0.154 0.045 0.01 0.09 84 28,104 27,797 579 579 27,525 0.63 439.10 80 1200 20.00 0.2 0.035 0.152 0.030 0.01 0.06 56 27,581 27,724 578 578 27,004 0.62 439.08 81 1215 20.25 0.3 0.053 0.150 0.045 0.01 0.09 84 27,088 27,655 576 576 26,512 0.61 439.07 82 1230 20.50 0.3 0.053 0.148 0.045 0.01 0.09 84 26,596 27,586 575 575 26,022 0.60 439.05 83 1245 20.75 0.3 0.053 0.146 0.045 0.01 0.09 84 26,106 27,518 573 573 25,533 0.59 439.03 84 1260 21.00 0.2 0.035 0.145 0.030 0.01 0.06 56 25,589 27,445 572 572 25,017 0.57 439.02 85 1275 21.25 0.3 0.053 0.143 0.045 0.01 0.09 84 25,101 27,377 570 570 24,531 0.56 439.00 86 1290 21.50 0.2 0.035 0.141 0.030 0.01 0.06 56 24,587 27,305 569 569 24,018 0.55 438.98 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 11.70 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.13 LAG TIME - MINUTES 9.48 C 0.00242 Maxwell Drywells UNIT TIME-PERCENT OF LAG 158%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 87 1305 21.75 0.3 0.053 0.140 0.045 0.01 0.09 84 24,103 27,201 567 567 23,536 0.54 438.96 88 1320 22.00 0.2 0.035 0.138 0.030 0.01 0.06 56 23,592 27,089 564 564 23,028 0.53 438.94 89 1335 22.25 0.3 0.053 0.137 0.045 0.01 0.09 84 23,112 26,984 562 562 22,550 0.52 438.92 90 1350 22.50 0.2 0.035 0.136 0.030 0.01 0.06 56 22,606 26,872 560 560 22,046 0.51 438.90 91 1365 22.75 0.2 0.035 0.134 0.030 0.01 0.06 56 22,103 26,762 558 558 21,545 0.49 438.88 92 1380 23.00 0.2 0.035 0.133 0.030 0.01 0.06 56 21,601 26,651 555 555 21,046 0.48 438.86 93 1395 23.25 0.2 0.035 0.132 0.030 0.01 0.06 56 21,102 26,542 553 553 20,549 0.47 438.84 94 1410 23.50 0.2 0.035 0.132 0.030 0.01 0.06 56 20,605 26,432 551 551 20,055 0.46 438.82 95 1425 23.75 0.2 0.035 0.131 0.030 0.01 0.06 56 20,111 26,324 548 548 19,563 0.45 438.80 96 1440 24.00 0.2 0.035 0.131 0.030 0.01 0.06 56 19,619 26,215 546 546 19,073 0.44 438.78 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 4.41 in 187,362 cu-ft 128,299 cu-ft 439.35 ft 4.43 cfs 39,990 cu-ft 27.77 cf/min 1.39 in 1.36 acft 59,063 cu-ft 0.80 acft 34,787 cu-ft Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 438 0 0 21,900 0 0 0.00 439 1 1 5,400 27,300 24,550 24,550 0.56 440 1 2 4,105 31,405 29,329 53,879 1.24 441 1 3 5,380 36,785 34,060 87,939 2.02 442 1 4 4,400 41,185 38,964 126,903 2.91 WHERE: TOTAL EXISTING BASIN BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 DLS 2 AMC II AREA SOIL TRIBUTARY AREAS ACRES LOW LOSS RI INFILTRATION IMPERVIOUS DESIG GROUP CONDITION NUMBER RATE PERCENT 2 B PAVING/HARDSCAPE 4.014 D 56 0.51 1.00 9 B LANDSCAPING 1.687 D 56 0.51 0.10 4,250 ft 2,125 ft 490.9 ft ELEVATION OF CONCENTRATION POINT 440.7 ft 0.02 100 LOW LOSS RATE (Storm Events > 10 Years)85% POINT RAIN FROM NOAA ATLAS 14 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in BASIN CHARACTERISTICS:ELEVATION AREA 436.0 ft 30,335 sf 437.0 ft 37,775 sf 438.0 ft 42,190 sf 439.0 ft 45,895 sf 440.0 ft 49,625 sf 441.0 ft 54,215 sf PERCOLATION RATE (in/hr)1.0 in/hr DRYWELL DATA NUMBER USED PERCOLATION RATE LOWEST FLOWLINE ELEVATION LOWEST PAD ELEVATION PROJECT NUMBER CONCENTRATION POINT DESIGNATION 2553 EXISTING BASIN AMC NUMBER RCFCD SYNTHETIC UNIT HYDROGRAPH - SHORTCUT METHOD DATA INPUT SHEET WORKSHEET PREPARED BY: PROJECT NAME DATE January 26, 2021 CORAL MOUNTAIN LENGTH OF WATERCOURSE (L) AREA DESIGNATION ELEVATION OF HEADWATER AVERAGE MANNINGS 'N' VALUE STORM FREQUENCY (YEAR) LENGTH TO POINT OPPOSITE CENTROID (Lca) Low Loss Conditions: X=Existing; D=Developed; BS=Retention OFF-SITE SOUTH Data Input Sheet Page 1 of 13 PROJECT: Job No.: BY:DATE:1/26/21 [1] AMC II [2] FREQUENCY-YEARS 100 FROM NOAA ATLAS 14 [3] STORM DURATION:Point Rain 1-HOUR 1.44 in 3-HOUR 2.14 in 6-HOUR 2.76 in 24-HOUR 4.41 in STORM DURATION 1-HOUR 3-HOUR 6-HOUR 24-HOUR RAINFALL VOLUME (cu-ft)29,800 44,287 57,117 91,264 SOIL LOSSES (cu-ft)3,585 10,683 21,044 50,595 EFFECTIVE RAIN (in)1.27 1.62 1.74 1.97 FLOOD VOLUME (cu-ft)26,215 33,604 36,073 40,668 (acre-ft)0.60 0.77 0.83 0.93 REQUIRED STORAGE (cu-ft)23,515 25,738 23,414 16,515 (acre-ft)0.54 0.59 0.54 0.38 FACTOR OF SAFETY 9.25 8.46 9.29 13.18 STORAGE PROVIDED (cu-ft) (acre-ft) PEAK FLOW (cfs)n/a 11.11 9.67 2.59 MAXIMUM WSEL (ft)436.69 436.76 436.69 436.49 DEPTH (ft)0.69 0.76 0.69 0.49 DIFFERENCE (ft) DIFFERENCE (ft) ESTIMATED TIME TO DEWATER BASIN Based on Total Flood Volume & Average Percolation Rate (days)0.4 0.5 0.7 1.0 EXISTING BASIN OFF-SITE SOUTH CORAL MOUNTAIN [10] H-FEET [9] ELEVATION OF CONCENTRATION POINT 5.701 PHYSICAL DATA [1] CONCENTRATION POINT HYDROLOGY MANUAL BASIC DATA CALCULATION FORM 2553 DLS RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD [2] AREA DESIGNATION [3] AREA - ACRES [4] L-FEET [5] L-MILES 4250 0.805 [13] L*LCA/S^0.5 7.90 [11] S-FEET/MILE [6] La-FEET [7] La-MILES [8] ELEVATION OF HEADWATER 0.041 2125.00 [12] S^0.5 0.402 62.4 490.9 440.7 50.2 0.02 [17] 100% OF LAG-MINUTES 8.6 8.6 [14] AVERAGE MANNINGS 'N' [15] LAG TIME-HOURS 0.14 [16] LAG TIME-MINUTES [18] 200% OF LAG-MINUTES RAINFALL DATA 17.1 NOTE: PEAK FLOW FOR THE 1-HOUR STORM IS NOT REPRESENTATIVE. PER RCFCD PEAK DISCHARGES FROM THE 3-HOUR STORM SHOULD NORMALLY COMPARE WELL WITH RATIONAL PEAKS. LOWEST PAD ELEVATION LOWEST FLOWLINE ELEVATION STORM EVENT SUMMARY 217,630 5.00 Plate E-2.1 Page 2 of 13 PROJECT: Job No.: BY:DATE:1/26/21 MAX LOW LOW MIN SOIL RI PERVIOUS DECIMAL ADJUSTED AREA AREA AVERAGE LOSS LOSS RATE AVERAGE GROUP NUMBER AREA PERCENT INFILTRATION WEIGHTED ADJUSTED CONDITION PER ADJUSTED INFILTRATION OF AREA RATE AVERAGE INFILTRATION RCFC/2322 INFILTRATION RATE IMPERVIOUS RATE RATE (in/hr)(in/hr)(in/hr) [Plate C-1][Plate E-6.1][Plate E-6.2][Plate E-6.3] B 56 0.51 100%0.05 4.014 0.704 0.0359 DEVELOPED 0.1000 0.0704 B 56 0.51 10%0.46 1.687 0.296 0.1373 DEVELOPED 0.8200 0.2426 SUM 5.701 SUM 0.1732 0.3131 VARIABLE LOSS RATE CURVE (24-HOUR STORM ONLY) Fm=0.08662083 NOTE: Low loss rates established per RCFC/2322 (Dated: May-30-95) C=0.00160 For 10 Year Storms or Less Ft=C(24-(T/60))^1.55+Fm =0.00160 0.09 in/hr Undeveloped Condition: Low Loss = 90% CONSTANT LOSS RATE (3 & 6 HOUR STORMS)=0.1732 Developed Condition: Low Loss = 0.9 - (0.8 * %impervious) LOW LOSS RATE =0.8500 Basin Site: Low Loss = 10% Where:For 100 Year Storm - Low Loss should be between 80% & 90% T=Time in minutes. To get an average value for each unit time period, Use T=1/2 the unit time for the first time period,of the Rainfall Rate T=1 1/2 unit time for the second period, etc. AVERAGE ADJUSTED LOSS RATE RCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD BASIC DATA CALCULATION FORM CORAL MOUNTAIN DLS 2553 AMC II (24-(T/60))^1.55 + LAND USE PAVING/HARDSCAPE LANDSCAPING Plate E-2.1 Page 3 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 5.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 8.56 Maxwell Drywells UNIT TIME-PERCENT OF LAG 58.4 Number 0 TOTAL ADJUSTED STORM RAIN-INCHES 1.44 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE-in/hr 0.17 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 3.6 0.62 0.17 0.53 0.45 2.58 774 774 30,504 212 212 562 0.01 436.02 2 10 0.17 4.2 0.73 0.17 0.62 0.55 3.18 953 1,515 30,667 213 213 1,302 0.03 436.04 3 15 0.25 4.4 0.76 0.17 0.65 0.59 3.37 1,012 2,315 30,842 214 214 2,100 0.05 436.06 4 20 0.33 4.6 0.79 0.17 0.68 0.62 3.57 1,072 3,172 31,029 215 215 2,957 0.07 436.09 5 25 0.42 5.0 0.86 0.17 0.73 0.69 3.97 1,191 4,148 31,243 217 217 3,931 0.09 436.12 6 30 0.50 5.6 0.97 0.17 0.82 0.79 4.57 1,370 5,301 31,495 219 219 5,083 0.12 436.15 7 35 0.58 6.4 1.11 0.17 0.94 0.93 5.36 1,608 6,691 31,800 221 221 6,470 0.15 436.19 8 40 0.67 8.1 1.40 0.17 1.19 1.23 7.05 2,115 8,585 32,214 224 224 8,362 0.19 436.25 9 45 0.75 13.1 2.26 0.17 1.92 2.09 12.02 3,605 11,967 32,955 229 229 11,738 0.27 436.35 10 50 0.83 34.5 5.96 0.17 5.07 5.79 33.27 9,982 21,720 35,090 244 244 21,476 0.49 436.63 11 55 0.92 6.7 1.16 0.17 0.98 0.98 5.66 1,698 23,174 35,408 246 246 22,928 0.53 436.67 12 60 1.00 3.8 0.66 0.17 0.56 0.48 2.78 834 23,762 35,537 247 247 23,515 0.54 436.69 TOTAL RAINFALL 1.44 in RAINFALL VOLUME 29,800 cu-ft SOIL LOSSES 3,585 cu-ft EFFECTIVE RAIN 1.27 in FLOOD VOLUME 0.60 acft FLOOD VOLUME 26,215 cu-ft REQUIRED STORAGE 0.54 REQUIRED STORAGE 23,515 cu-ft MAX WSEL 436.69 ft PEAK FLOW RATE 33.27 cfs TOTAL BASIN LOSSES 2,700 cu-ft AVERAGE PERCOLATION RATE 45.00 cf/min CORAL MOUNTAINRCFC & WCD HYDROLOGY MANUAL SYNTHETIC UNIT HYDROGRAPH METHOD SHORTCUT METHOD 1-HOUR STORM EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Total In Basin in/hr Time Loss Rate Basin Losses Plate E-2.2 1-Hour Storm Page 4 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 5.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 8.56 Maxwell Drywells UNIT TIME-PERCENT OF LAG 58.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.17 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 1.3 0.33 0.17 0.28 0.16 0.92 277 277 30,396 211 211 66 0.00 436.00 2 10 0.17 1.3 0.33 0.17 0.28 0.16 0.92 277 343 30,410 211 211 132 0.00 436.00 3 15 0.25 1.1 0.28 0.17 0.24 0.11 0.63 188 320 30,405 211 211 109 0.00 436.00 4 20 0.33 1.5 0.39 0.17 0.33 0.21 1.22 366 474 30,439 211 211 263 0.01 436.01 5 25 0.42 1.5 0.39 0.17 0.33 0.21 1.22 366 629 30,473 212 212 417 0.01 436.01 6 30 0.50 1.8 0.46 0.17 0.39 0.29 1.66 498 915 30,535 212 212 703 0.02 436.02 7 35 0.58 1.5 0.39 0.17 0.33 0.21 1.22 366 1,069 30,569 212 212 857 0.02 436.03 8 40 0.67 1.8 0.46 0.17 0.39 0.29 1.66 498 1,355 30,632 213 213 1,142 0.03 436.03 9 45 0.75 1.8 0.46 0.17 0.39 0.29 1.66 498 1,641 30,694 213 213 1,427 0.03 436.04 10 50 0.83 1.5 0.39 0.17 0.33 0.21 1.22 366 1,793 30,728 213 213 1,580 0.04 436.05 11 55 0.92 1.6 0.41 0.17 0.35 0.24 1.37 410 1,989 30,771 214 214 1,776 0.04 436.05 12 60 1.00 1.8 0.46 0.17 0.39 0.29 1.66 498 2,274 30,833 214 214 2,060 0.05 436.06 13 65 1.08 2.2 0.56 0.17 0.48 0.39 2.25 676 2,736 30,934 215 215 2,521 0.06 436.07 14 70 1.17 2.2 0.56 0.17 0.48 0.39 2.25 676 3,196 31,035 216 216 2,981 0.07 436.09 15 75 1.25 2.2 0.56 0.17 0.48 0.39 2.25 676 3,656 31,135 216 216 3,440 0.08 436.10 16 80 1.33 2.0 0.51 0.17 0.44 0.34 1.96 587 4,027 31,217 217 217 3,810 0.09 436.11 17 85 1.42 2.6 0.67 0.17 0.57 0.49 2.84 853 4,663 31,356 218 218 4,445 0.10 436.13 18 90 1.50 2.7 0.69 0.17 0.59 0.52 2.99 897 5,342 31,504 219 219 5,123 0.12 436.15 19 95 1.58 2.4 0.62 0.17 0.52 0.44 2.55 764 5,888 31,624 220 220 5,668 0.13 436.17 20 100 1.67 2.7 0.69 0.17 0.59 0.52 2.99 897 6,565 31,772 221 221 6,344 0.15 436.19 21 105 1.75 3.3 0.85 0.17 0.72 0.67 3.88 1,163 7,507 31,978 222 222 7,285 0.17 436.21 22 110 1.83 3.1 0.80 0.17 0.68 0.62 3.58 1,074 8,359 32,165 223 223 8,136 0.19 436.24 23 115 1.92 2.9 0.74 0.17 0.63 0.57 3.29 986 9,121 32,332 225 225 8,897 0.20 436.26 24 120 2.00 3.0 0.77 0.17 0.65 0.60 3.43 1,030 9,927 32,508 226 226 9,701 0.22 436.29 25 125 2.08 3.1 0.80 0.17 0.68 0.62 3.58 1,074 10,775 32,694 227 227 10,548 0.24 436.31 Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Plate E-2.2 3-Hour Storm Page 5 of 13 PROJECT: Job No.:2553 BY:DLS DATE DRAINAGE AREA-ACRES 5.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 8.56 Maxwell Drywells UNIT TIME-PERCENT OF LAG 58.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.14 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.17 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Total In Basin in/hr MANUAL 3-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Loss Rate Basin Losses RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD 26 130 2.17 4.2 1.08 0.17 0.92 0.91 5.20 1,561 12,109 32,986 229 229 11,880 0.27 436.35 27 135 2.25 5.0 1.28 0.17 1.09 1.11 6.39 1,916 13,796 33,355 232 232 13,564 0.31 436.40 28 140 2.33 3.5 0.90 0.17 0.76 0.73 4.17 1,251 14,815 33,578 233 233 14,582 0.33 436.43 29 145 2.42 6.8 1.75 0.17 1.48 1.57 9.04 2,713 17,295 34,121 237 237 17,058 0.39 436.50 30 150 2.50 7.3 1.87 0.17 1.59 1.70 9.78 2,934 19,992 34,711 241 241 19,751 0.45 436.58 31 155 2.58 8.2 2.11 0.17 1.79 1.93 11.11 3,333 23,084 35,388 246 246 22,838 0.52 436.67 32 160 2.67 5.9 1.52 0.17 1.29 1.34 7.71 2,314 25,152 35,841 249 249 24,903 0.57 436.73 33 165 2.75 2.0 0.51 0.17 0.44 0.34 1.96 587 25,490 35,915 249 249 25,241 0.58 436.74 34 170 2.83 1.8 0.46 0.17 0.39 0.29 1.66 498 25,739 35,969 250 250 25,489 0.59 436.75 35 175 2.92 1.8 0.46 0.17 0.39 0.29 1.66 498 25,988 36,024 250 250 25,738 0.59 436.76 36 180 3.00 0.6 0.15 0.17 0.13 0.02 0.13 40 25,777 35,978 250 250 25,528 0.59 436.75 TOTAL RAIN RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 10,683 cu-ft 2.14 in 44,287 cu-ft 436.76 ft 11.11 cfs 8,076 cu-ft 44.87 cf/min 1.62 in 0.77 acft 33,604 cu-ft 0.59 acft 25,738 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 3-Hour Storm Page 6 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 5.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 8.56 Maxwell Drywells UNIT TIME-PERCENT OF LAG 58.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.17 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 5 0.08 0.5 0.17 0.17 0.14 0.02 0.14 43 43 30,344 211 43 0 0.00 436.00 2 10 0.17 0.6 0.20 0.17 0.17 0.03 0.15 44 44 30,345 211 44 0 0.00 436.00 3 15 0.25 0.6 0.20 0.17 0.17 0.03 0.15 44 44 30,345 211 44 0 0.00 436.00 4 20 0.33 0.6 0.20 0.17 0.17 0.03 0.15 44 44 30,345 211 44 0 0.00 436.00 5 25 0.42 0.6 0.20 0.17 0.17 0.03 0.15 44 44 30,345 211 44 0 0.00 436.00 6 30 0.50 0.7 0.23 0.17 0.20 0.06 0.34 101 101 30,357 211 101 0 0.00 436.00 7 35 0.58 0.7 0.23 0.17 0.20 0.06 0.34 101 101 30,357 211 101 0 0.00 436.00 8 40 0.67 0.7 0.23 0.17 0.20 0.06 0.34 101 101 30,357 211 101 0 0.00 436.00 9 45 0.75 0.7 0.23 0.17 0.20 0.06 0.34 101 101 30,357 211 101 0 0.00 436.00 10 50 0.83 0.7 0.23 0.17 0.20 0.06 0.34 101 101 30,357 211 101 0 0.00 436.00 11 55 0.92 0.7 0.23 0.17 0.20 0.06 0.34 101 101 30,357 211 101 0 0.00 436.00 12 60 1.00 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 13 65 1.08 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 14 70 1.17 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 15 75 1.25 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 16 80 1.33 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 17 85 1.42 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 18 90 1.50 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 19 95 1.58 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 20 100 1.67 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 21 105 1.75 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 22 110 1.83 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 23 115 1.92 0.8 0.26 0.17 0.23 0.09 0.53 158 158 30,370 211 158 0 0.00 436.00 24 120 2.00 0.9 0.30 0.17 0.25 0.12 0.72 215 215 30,382 211 211 4 0.00 436.00 Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses Plate E-2.2 6-Hour Storm Page 7 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 5.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 8.56 Maxwell Drywells UNIT TIME-PERCENT OF LAG 58.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.17 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 25 125 2.08 0.8 0.26 0.17 0.23 0.09 0.53 158 162 30,371 211 162 0 0.00 436.00 26 130 2.17 0.9 0.30 0.17 0.25 0.12 0.72 215 215 30,382 211 211 4 0.00 436.00 27 135 2.25 0.9 0.30 0.17 0.25 0.12 0.72 215 220 30,383 211 211 9 0.00 436.00 28 140 2.33 0.9 0.30 0.17 0.25 0.12 0.72 215 224 30,384 211 211 13 0.00 436.00 29 145 2.42 0.9 0.30 0.17 0.25 0.12 0.72 215 228 30,385 211 211 17 0.00 436.00 30 150 2.50 0.9 0.30 0.17 0.25 0.12 0.72 215 232 30,386 211 211 21 0.00 436.00 31 155 2.58 0.9 0.30 0.17 0.25 0.12 0.72 215 237 30,387 211 211 26 0.00 436.00 32 160 2.67 0.9 0.30 0.17 0.25 0.12 0.72 215 241 30,388 211 211 30 0.00 436.00 33 165 2.75 1.0 0.33 0.17 0.28 0.16 0.91 272 302 30,401 211 211 91 0.00 436.00 34 170 2.83 1.0 0.33 0.17 0.28 0.16 0.91 272 364 30,415 211 211 152 0.00 436.00 35 175 2.92 1.0 0.33 0.17 0.28 0.16 0.91 272 425 30,428 211 211 214 0.00 436.01 36 180 3.00 1.0 0.33 0.17 0.28 0.16 0.91 272 486 30,441 211 211 275 0.01 436.01 37 185 3.08 1.0 0.33 0.17 0.28 0.16 0.91 272 547 30,455 211 211 336 0.01 436.01 38 190 3.17 1.1 0.36 0.17 0.31 0.19 1.10 330 665 30,481 212 212 453 0.01 436.01 39 195 3.25 1.1 0.36 0.17 0.31 0.19 1.10 330 783 30,506 212 212 571 0.01 436.02 40 200 3.33 1.1 0.36 0.17 0.31 0.19 1.10 330 901 30,532 212 212 689 0.02 436.02 41 205 3.42 1.2 0.40 0.17 0.34 0.22 1.29 387 1,075 30,570 212 212 863 0.02 436.03 42 210 3.50 1.3 0.43 0.17 0.37 0.26 1.48 444 1,307 30,621 213 213 1,094 0.03 436.03 43 215 3.58 1.4 0.46 0.17 0.39 0.29 1.67 501 1,595 30,684 213 213 1,382 0.03 436.04 44 220 3.67 1.4 0.46 0.17 0.39 0.29 1.67 501 1,883 30,747 214 214 1,669 0.04 436.05 45 225 3.75 1.5 0.50 0.17 0.42 0.32 1.86 558 2,227 30,823 214 214 2,013 0.05 436.06 46 230 3.83 1.5 0.50 0.17 0.42 0.32 1.86 558 2,571 30,898 215 215 2,357 0.05 436.07 47 235 3.92 1.6 0.53 0.17 0.45 0.36 2.05 615 2,972 30,986 215 215 2,756 0.06 436.08 48 240 4.00 1.6 0.53 0.17 0.45 0.36 2.05 615 3,372 31,073 216 216 3,156 0.07 436.09 49 245 4.08 1.7 0.56 0.17 0.48 0.39 2.24 672 3,828 31,173 216 216 3,612 0.08 436.11 50 250 4.17 1.8 0.60 0.17 0.51 0.42 2.43 729 4,341 31,285 217 217 4,124 0.09 436.12 Plate E-2.2 6-Hour Storm Page 8 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 5.70 Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 5 LAG TIME - MINUTES 8.56 Maxwell Drywells UNIT TIME-PERCENT OF LAG 58.4 Number 0 TOTAL ADJUSTED STORM RAIN (in)2.76 Drywell Percolation Rate 0.00 cfs 0.00 cfm CONSTANT LOSS RATE (in/hr)0.17 LOW LOSS RATE - PERCENT 85.00% Unit Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft Loss Rate RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD Total In Basin in/hr MANUAL 6-HOUR STORM UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Time Basin Losses 51 255 4.25 1.9 0.63 0.17 0.53 0.46 2.62 786 4,910 31,410 218 218 4,692 0.11 436.14 52 260 4.33 2.0 0.66 0.17 0.56 0.49 2.81 844 5,536 31,547 219 219 5,316 0.12 436.16 53 265 4.42 2.1 0.70 0.17 0.59 0.52 3.00 901 6,217 31,696 220 220 5,997 0.14 436.18 54 270 4.50 2.1 0.70 0.17 0.59 0.52 3.00 901 6,898 31,845 221 221 6,677 0.15 436.20 55 275 4.58 2.2 0.73 0.17 0.62 0.56 3.19 958 7,634 32,006 222 222 7,412 0.17 436.22 56 280 4.67 2.3 0.76 0.17 0.65 0.59 3.38 1,015 8,427 32,180 223 223 8,204 0.19 436.24 57 285 4.75 2.4 0.79 0.17 0.68 0.62 3.57 1,072 9,276 32,366 225 225 9,051 0.21 436.27 58 290 4.83 2.4 0.79 0.17 0.68 0.62 3.57 1,072 10,123 32,551 226 226 9,897 0.23 436.29 59 295 4.92 2.5 0.83 0.17 0.70 0.65 3.76 1,129 11,026 32,749 227 227 10,799 0.25 436.32 60 300 5.00 2.6 0.86 0.17 0.73 0.69 3.95 1,186 11,985 32,959 229 229 11,756 0.27 436.35 61 305 5.08 3.1 1.03 0.17 0.87 0.85 4.91 1,472 13,228 33,231 231 231 12,997 0.30 436.38 62 310 5.17 3.6 1.19 0.17 1.01 1.02 5.86 1,757 14,755 33,565 233 233 14,522 0.33 436.43 63 315 5.25 3.9 1.29 0.17 1.10 1.12 6.43 1,929 16,450 33,936 236 236 16,215 0.37 436.48 64 320 5.33 4.2 1.39 0.17 1.18 1.22 7.00 2,100 18,315 34,344 239 239 18,076 0.41 436.53 65 325 5.42 4.7 1.56 0.17 1.32 1.38 7.95 2,386 20,462 34,814 242 242 20,220 0.46 436.59 66 330 5.50 5.6 1.85 0.17 1.58 1.68 9.67 2,900 23,120 35,396 246 246 22,874 0.53 436.67 67 335 5.58 1.9 0.63 0.17 0.53 0.46 2.62 786 23,661 35,515 247 247 23,414 0.54 436.69 68 340 5.67 0.9 0.30 0.17 0.25 0.12 0.72 215 23,629 35,508 247 247 23,383 0.54 436.69 69 345 5.75 0.6 0.20 0.17 0.17 0.03 0.15 44 23,427 35,463 246 246 23,181 0.53 436.68 70 350 5.83 0.5 0.17 0.17 0.14 0.02 0.14 43 23,223 35,419 246 246 22,977 0.53 436.68 71 355 5.92 0.3 0.10 0.17 0.08 0.01 0.09 26 23,003 35,371 246 246 22,758 0.52 436.67 72 360 6.00 0.2 0.07 0.17 0.06 0.01 0.06 17 22,775 35,321 245 245 22,529 0.52 436.66 TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 57,117 cu-ft 2.76 in 21,044 cu-ft 436.69 ft 9.67 cfs 37.62 cf/min 13,544 cu-ft 1.74 in 0.83 acft 36,073 cu-ft 0.54 acft 23,414 cu-ft EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY Plate E-2.2 6-Hour Storm Page 9 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 5.70 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.09 LAG TIME - MINUTES 8.56 C 0.00160 Maxwell Drywells UNIT TIME-PERCENT OF LAG 175%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft 1 15 0.25 0.2 0.035 0.306 0.030 0.01 0.03 27 27 30,341 632 27 0 0.00 436.00 2 30 0.50 0.3 0.053 0.302 0.045 0.01 0.05 41 41 30,344 632 41 0 0.00 436.00 3 45 0.75 0.3 0.053 0.299 0.045 0.01 0.05 41 41 30,344 632 41 0 0.00 436.00 4 60 1.00 0.4 0.071 0.295 0.060 0.01 0.06 55 55 30,347 632 55 0 0.00 436.00 5 75 1.25 0.3 0.053 0.292 0.045 0.01 0.05 41 41 30,344 632 41 0 0.00 436.00 6 90 1.50 0.3 0.053 0.288 0.045 0.01 0.05 41 41 30,344 632 41 0 0.00 436.00 7 105 1.75 0.3 0.053 0.285 0.045 0.01 0.05 41 41 30,344 632 41 0 0.00 436.00 8 120 2.00 0.4 0.071 0.282 0.060 0.01 0.06 55 55 30,347 632 55 0 0.00 436.00 9 135 2.25 0.4 0.071 0.278 0.060 0.01 0.06 55 55 30,347 632 55 0 0.00 436.00 10 150 2.50 0.4 0.071 0.275 0.060 0.01 0.06 55 55 30,347 632 55 0 0.00 436.00 11 165 2.75 0.5 0.088 0.271 0.075 0.01 0.08 68 68 30,350 632 68 0 0.00 436.00 12 180 3.00 0.5 0.088 0.268 0.075 0.01 0.08 68 68 30,350 632 68 0 0.00 436.00 13 195 3.25 0.5 0.088 0.265 0.075 0.01 0.08 68 68 30,350 632 68 0 0.00 436.00 14 210 3.50 0.5 0.088 0.261 0.075 0.01 0.08 68 68 30,350 632 68 0 0.00 436.00 15 225 3.75 0.5 0.088 0.258 0.075 0.01 0.08 68 68 30,350 632 68 0 0.00 436.00 16 240 4.00 0.6 0.106 0.255 0.090 0.02 0.09 82 82 30,353 632 82 0 0.00 436.00 17 255 4.25 0.6 0.106 0.252 0.090 0.02 0.09 82 82 30,353 632 82 0 0.00 436.00 18 270 4.50 0.7 0.123 0.248 0.105 0.02 0.11 96 96 30,356 632 96 0 0.00 436.00 19 285 4.75 0.7 0.123 0.245 0.105 0.02 0.11 96 96 30,356 632 96 0 0.00 436.00 20 300 5.00 0.8 0.141 0.242 0.120 0.02 0.12 110 110 30,359 632 110 0 0.00 436.00 21 315 5.25 0.6 0.106 0.239 0.090 0.02 0.09 82 82 30,353 632 82 0 0.00 436.00 22 330 5.50 0.7 0.123 0.236 0.105 0.02 0.11 96 96 30,356 632 96 0 0.00 436.00 23 345 5.75 0.8 0.141 0.233 0.120 0.02 0.12 110 110 30,359 632 110 0 0.00 436.00 24 360 6.00 0.8 0.141 0.230 0.120 0.02 0.12 110 110 30,359 632 110 0 0.00 436.00 25 375 6.25 0.9 0.159 0.227 0.135 0.02 0.14 123 123 30,362 633 123 0 0.00 436.00 26 390 6.50 0.9 0.159 0.224 0.135 0.02 0.14 123 123 30,362 633 123 0 0.00 436.00 27 405 6.75 1.0 0.176 0.221 0.150 0.03 0.15 137 137 30,365 633 137 0 0.00 436.00 28 420 7.00 1.0 0.176 0.218 0.150 0.03 0.15 137 137 30,365 633 137 0 0.00 436.00 29 435 7.25 1.0 0.176 0.215 0.150 0.03 0.15 137 137 30,365 633 137 0 0.00 436.00 30 450 7.50 1.1 0.194 0.212 0.165 0.03 0.17 151 151 30,368 633 151 0 0.00 436.00 31 465 7.75 1.2 0.212 0.209 0.180 0.00 0.02 15 15 30,338 632 15 0 0.00 436.00 32 480 8.00 1.3 0.229 0.206 0.195 0.02 0.13 121 121 30,361 633 121 0 0.00 436.00 33 495 8.25 1.5 0.265 0.203 0.225 0.06 0.35 318 318 30,405 633 318 0 0.00 436.00 34 510 8.50 1.5 0.265 0.200 0.225 0.06 0.37 333 333 30,408 633 333 0 0.00 436.00 35 525 8.75 1.6 0.282 0.197 0.240 0.08 0.49 438 438 30,431 634 438 0 0.00 436.00 36 540 9.00 1.7 0.300 0.195 0.255 0.11 0.60 544 544 30,454 634 544 0 0.00 436.00 37 555 9.25 1.9 0.335 0.192 0.285 0.14 0.82 741 741 30,497 635 635 106 0.00 436.00 38 570 9.50 2.0 0.353 0.189 0.300 0.16 0.94 846 952 30,543 636 636 316 0.01 436.01 39 585 9.75 2.1 0.370 0.187 0.315 0.18 1.06 952 1,267 30,612 638 638 629 0.01 436.02 40 600 10.00 2.2 0.388 0.184 0.330 0.20 1.17 1,057 1,686 30,704 640 640 1,046 0.02 436.03 41 615 10.25 1.5 0.265 0.181 0.225 0.08 0.48 432 1,478 30,659 639 639 839 0.02 436.02 42 630 10.50 1.5 0.265 0.179 0.225 0.09 0.49 445 1,285 30,616 638 638 647 0.01 436.02 43 645 10.75 2.0 0.353 0.176 0.300 0.18 1.02 915 1,562 30,677 639 639 923 0.02 436.03 RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM Plate E-2.2 24-Hour Storm Page 10 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 5.70 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.09 LAG TIME - MINUTES 8.56 C 0.00160 Maxwell Drywells UNIT TIME-PERCENT OF LAG 175%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 44 660 11.00 2.0 0.353 0.173 0.300 0.18 1.03 928 1,851 30,740 640 640 1,210 0.03 436.04 45 675 11.25 1.9 0.335 0.171 0.285 0.16 0.94 850 2,061 30,786 641 641 1,419 0.03 436.04 46 690 11.50 1.9 0.335 0.168 0.285 0.17 0.96 863 2,283 30,835 642 642 1,640 0.04 436.05 47 705 11.75 1.7 0.300 0.166 0.255 0.13 0.77 694 2,334 30,846 643 643 1,691 0.04 436.05 48 720 12.00 1.8 0.318 0.163 0.270 0.15 0.89 798 2,489 30,880 643 643 1,845 0.04 436.05 49 735 12.25 2.5 0.441 0.161 0.375 0.28 1.61 1,449 3,295 31,056 647 647 2,648 0.06 436.08 50 750 12.50 2.6 0.459 0.158 0.390 0.30 1.73 1,553 4,200 31,255 651 651 3,549 0.08 436.10 51 765 12.75 2.8 0.494 0.156 0.420 0.34 1.94 1,748 5,297 31,495 656 656 4,641 0.11 436.14 52 780 13.00 2.9 0.512 0.154 0.435 0.36 2.06 1,851 6,492 31,756 662 662 5,830 0.13 436.17 53 795 13.25 3.4 0.600 0.151 0.510 0.45 2.58 2,319 8,150 32,119 669 669 7,481 0.17 436.22 54 810 13.50 3.4 0.600 0.149 0.510 0.45 2.59 2,331 9,812 32,483 677 677 9,135 0.21 436.27 55 825 13.75 2.3 0.406 0.147 0.345 0.26 1.49 1,339 10,475 32,628 680 680 9,795 0.22 436.29 56 840 14.00 2.3 0.406 0.145 0.345 0.26 1.50 1,351 11,145 32,775 683 683 10,463 0.24 436.31 57 855 14.25 2.7 0.476 0.142 0.405 0.33 1.92 1,727 12,190 33,003 688 688 11,502 0.26 436.34 58 870 14.50 2.6 0.459 0.140 0.390 0.32 1.83 1,647 13,149 33,214 692 692 12,458 0.29 436.37 59 885 14.75 2.6 0.459 0.138 0.390 0.32 1.84 1,658 14,116 33,425 696 696 13,419 0.31 436.39 60 900 15.00 2.5 0.441 0.136 0.375 0.30 1.75 1,578 14,997 33,618 700 700 14,297 0.33 436.42 61 915 15.25 2.4 0.423 0.134 0.360 0.29 1.66 1,497 15,794 33,793 704 704 15,090 0.35 436.44 62 930 15.50 2.3 0.406 0.132 0.345 0.27 1.57 1,417 16,507 33,949 707 707 15,800 0.36 436.46 63 945 15.75 1.9 0.335 0.130 0.285 0.21 1.18 1,062 16,862 34,026 709 709 16,153 0.37 436.48 64 960 16.00 1.9 0.335 0.128 0.285 0.21 1.19 1,072 17,226 34,106 711 711 16,515 0.38 436.49 65 975 16.25 0.4 0.071 0.126 0.060 0.01 0.06 55 16,570 33,962 708 708 15,862 0.36 436.47 66 990 16.50 0.4 0.071 0.124 0.060 0.01 0.06 55 15,917 33,819 705 705 15,213 0.35 436.45 67 1005 16.75 0.3 0.053 0.122 0.045 0.01 0.05 41 15,254 33,674 702 702 14,552 0.33 436.43 68 1020 17.00 0.3 0.053 0.120 0.045 0.01 0.05 41 14,593 33,530 699 699 13,895 0.32 436.41 69 1035 17.25 0.5 0.088 0.118 0.075 0.01 0.08 68 13,963 33,392 696 696 13,267 0.30 436.39 70 1050 17.50 0.5 0.088 0.117 0.075 0.01 0.08 68 13,336 33,254 693 693 12,643 0.29 436.37 71 1065 17.75 0.5 0.088 0.115 0.075 0.01 0.08 68 12,712 33,118 690 690 12,022 0.28 436.35 72 1080 18.00 0.4 0.071 0.113 0.060 0.01 0.06 55 12,076 32,979 687 687 11,389 0.26 436.34 73 1095 18.25 0.4 0.071 0.112 0.060 0.01 0.06 55 11,444 32,840 684 684 10,760 0.25 436.32 74 1110 18.50 0.4 0.071 0.110 0.060 0.01 0.06 55 10,815 32,702 681 681 10,133 0.23 436.30 75 1125 18.75 0.3 0.053 0.108 0.045 0.01 0.05 41 10,174 32,562 678 678 9,496 0.22 436.28 76 1140 19.00 0.2 0.035 0.107 0.030 0.01 0.03 27 9,523 32,420 675 675 8,848 0.20 436.26 77 1155 19.25 0.3 0.053 0.105 0.045 0.01 0.05 41 8,889 32,281 673 673 8,217 0.19 436.24 78 1170 19.50 0.4 0.071 0.104 0.060 0.01 0.06 55 8,271 32,146 670 670 7,602 0.17 436.22 79 1185 19.75 0.3 0.053 0.102 0.045 0.01 0.05 41 7,643 32,008 667 667 6,976 0.16 436.21 80 1200 20.00 0.2 0.035 0.101 0.030 0.01 0.03 27 7,003 31,868 664 664 6,339 0.15 436.19 81 1215 20.25 0.3 0.053 0.100 0.045 0.01 0.05 41 6,380 31,732 661 661 5,719 0.13 436.17 82 1230 20.50 0.3 0.053 0.098 0.045 0.01 0.05 41 5,760 31,596 658 658 5,102 0.12 436.15 83 1245 20.75 0.3 0.053 0.097 0.045 0.01 0.05 41 5,143 31,461 655 655 4,488 0.10 436.13 84 1260 21.00 0.2 0.035 0.096 0.030 0.01 0.03 27 4,515 31,323 653 653 3,863 0.09 436.11 85 1275 21.25 0.3 0.053 0.095 0.045 0.01 0.05 41 3,904 31,190 650 650 3,254 0.07 436.10 86 1290 21.50 0.2 0.035 0.094 0.030 0.01 0.03 27 3,281 31,053 647 647 2,634 0.06 436.08 Plate E-2.2 24-Hour Storm Page 11 of 13 PROJECT: Job No.:2553 BY:DLS DATE 1/26/21 DRAINAGE AREA-ACRES 5.70 VARIABLE LOSS RATE (AVG) IN/HR Basin Percolation Rate 1.0 in/hr UNIT TIME-MINUTES 15 Fm = Minimum value on loss curve (in/hr)0.09 LAG TIME - MINUTES 8.56 C 0.00160 Maxwell Drywells UNIT TIME-PERCENT OF LAG 175%Low Loss Rate (percent)85.00%Number 0 TOTAL ADJUSTED STORM RAIN (in)4.41 Drywell Percolation Rate 0.00 cfs 0.00 cfm Unit Time Time Pattern Storm Effective Flood Volume Basin Basin Period Minutes Hours Percent Rain Rain Hydrograph In Volume Percolation Maximum Percolation WSEL in/hr Flow Area Percolation Out (Plate E-5.9)Max Low in/hr cfs cu-ft cu-ft sf cu-ft cu-ft cu-ft ac-ft ft RCFC & WCD SYNTHETIC UNIT HYDROGRAPH METHOD Loss Rate CORAL MOUNTAIN HYDROLOGY SHORTCUT METHOD MANUAL 24-HOUR STORM Basin Losses in/hr Total In Basin UNIT HYDROGRAPH and EFFECTIVE RAIN CALCULATION FORM 87 1305 21.75 0.3 0.053 0.093 0.045 0.01 0.05 41 2,675 30,921 644 644 2,031 0.05 436.06 88 1320 22.00 0.2 0.035 0.092 0.030 0.01 0.03 27 2,059 30,786 641 641 1,417 0.03 436.04 89 1335 22.25 0.3 0.053 0.091 0.045 0.01 0.05 41 1,458 30,654 639 639 820 0.02 436.02 90 1350 22.50 0.2 0.035 0.090 0.030 0.01 0.03 27 847 30,520 636 636 211 0.00 436.01 91 1365 22.75 0.2 0.035 0.089 0.030 0.01 0.03 27 239 30,387 633 239 0 0.00 436.00 92 1380 23.00 0.2 0.035 0.089 0.030 0.01 0.03 27 27 30,341 632 27 0 0.00 436.00 93 1395 23.25 0.2 0.035 0.088 0.030 0.01 0.03 27 27 30,341 632 27 0 0.00 436.00 94 1410 23.50 0.2 0.035 0.087 0.030 0.01 0.03 27 27 30,341 632 27 0 0.00 436.00 95 1425 23.75 0.2 0.035 0.087 0.030 0.01 0.03 27 27 30,341 632 27 0 0.00 436.00 96 1440 24.00 0.2 0.035 0.087 0.030 0.01 0.03 27 27 30,341 632 27 0 0.00 436.00 EFFECTIVE RAIN & FLOOD VOLUMES SUMMARY TOTAL RAINFALL RAINFALL VOLUME SOIL LOSSES EFFECTIVE RAIN FLOOD VOLUME FLOOD VOLUME REQUIRED STORAGE REQUIRED STORAGE MAX WSEL PEAK FLOW RATE TOTAL BASIN LOSSES AVERAGE PERCOLATION RATE 4.41 in 91,264 cu-ft 50,595 cu-ft 436.49 ft 2.59 cfs 40,668 cu-ft 28.24 cf/min 1.97 in 0.93 acft 40,668 cu-ft 0.38 acft 16,515 cu-ft Plate E-2.2 24-Hour Storm Page 12 of 13 PROECT JOB No. BASIN DESIGNATION: BASIN CHARACTERISTICS CONTOUR ELEVATION INCR TOTAL INCR TOTAL INCR (ft)(ft)(sf)(sf)(cuft)(cuft)(acre-ft) 436 0 0 30,335 0 0 0.00 437 1 1 7,440 37,775 33,987 33,987 0.78 438 1 2 4,415 42,190 39,962 73,949 1.70 439 1 3 3,705 45,895 44,030 117,979 2.71 440 1 4 3,730 49,625 47,748 165,727 3.80 441 1 5 4,590 54,215 51,903 217,630 5.00 WHERE: TOTAL EXISTING BASIN BASIN VOLUME WORKSHEET DEPTH AREA VOLUME CORAL MOUNTAIN 2553 ( )()2121213 1 AAAAEEV++−= Basin Volume Worksheet Page 13 of 13 Coral Mountain Master Plan Hydrology Report Appendix G Riverside County Whitewater River Region WQMP Worksheets ATRIB = 162.745 acres Determine the Impervious Area Within ATRIB (AIMP)AIMP = 39.291 acres Calculate the Impervious Area Ratio (IF) IF = AIMP/ATRIB IF = 0.24 Use the following equation based on the WEF/ASCE Method CBMP = 0.858If 3 - 0.78If 2 + 0.774If + 0.04 CBMP = 0.19 Calculate VU, the 80% Unit Storage Volume VU = 0.40 x CBMP VU = 0.08 (in*ac)/ac Calculate the design storage volume of the BMP, VBMP VBMP (ft3) =VBMP = 45,719 ft3 QBMP = CBMP x I x ATRIB QBMP = 6.30 ft3/s I = Design Rainfall Intensity, 0.2 in/hr Legend: Required Entries Calculated Cells Determine the Impervious Area Ratio Whitewater Watershed BMP Design Volume, VBMP & Design Flow Rate , QBMP (Rev. 06-2014) Enter the Area Tributary to this Feature (ATRIB) MSA Consulting, Inc DLS Date County/City Case No. Notes: BMP Design Flow Rate, QBMP Company Name Designed By Company Project Number/Name Drainage Area Number/Name CORAL MOUNTAIN - MSA JOB #2553 DRAINAGE AREA 'A' January 26, 2021 VU (in-ac/ac) x AT (ac) x 43,560 (ft2/ac) 12(in/ft) Calculate the Composite Runoff Coefficient, C for the BMP Tributary Area Determine Design Storage Volume, VBMP ATRIB = 41.586 acres Determine the Impervious Area Within ATRIB (AIMP)AIMP = 17.518 acres Calculate the Impervious Area Ratio (IF) IF = AIMP/ATRIB IF = 0.42 Use the following equation based on the WEF/ASCE Method CBMP = 0.858If 3 - 0.78If 2 + 0.774If + 0.04 CBMP = 0.29 Calculate VU, the 80% Unit Storage Volume VU = 0.40 x CBMP VU = 0.12 (in*ac)/ac Calculate the design storage volume of the BMP, VBMP VBMP (ft3) =VBMP = 17,618 ft3 QBMP = CBMP x I x ATRIB QBMP = 2.43 ft3/s I = Design Rainfall Intensity, 0.2 in/hr Notes: BMP Design Flow Rate, QBMP Company Name Designed By Company Project Number/Name Drainage Area Number/Name CORAL MOUNTAIN - MSA JOB #2553 DRAINAGE AREA 'B' January 26, 2021 VU (in-ac/ac) x AT (ac) x 43,560 (ft2/ac) 12(in/ft) Calculate the Composite Runoff Coefficient, C for the BMP Tributary Area Determine Design Storage Volume, VBMP Legend: Required Entries Calculated Cells Determine the Impervious Area Ratio Whitewater Watershed BMP Design Volume, VBMP & Design Flow Rate , QBMP (Rev. 06-2014) Enter the Area Tributary to this Feature (ATRIB) MSA Consulting, Inc DLS Date County/City Case No. ATRIB = 55.002 acres Determine the Impervious Area Within ATRIB (AIMP)AIMP = 17.771 acres Calculate the Impervious Area Ratio (IF) IF = AIMP/ATRIB IF = 0.32 Use the following equation based on the WEF/ASCE Method CBMP = 0.858If 3 - 0.78If 2 + 0.774If + 0.04 CBMP = 0.24 Calculate VU, the 80% Unit Storage Volume VU = 0.40 x CBMP VU = 0.10 (in*ac)/ac Calculate the design storage volume of the BMP, VBMP VBMP (ft3) =VBMP = 18,975 ft3 QBMP = CBMP x I x ATRIB QBMP = 2.61 ft3/s I = Design Rainfall Intensity, 0.2 in/hr Legend: Required Entries Calculated Cells Determine the Impervious Area Ratio Whitewater Watershed BMP Design Volume, VBMP & Design Flow Rate , QBMP (Rev. 06-2014) Enter the Area Tributary to this Feature (ATRIB) MSA Consulting, Inc DLS Date County/City Case No. Notes: BMP Design Flow Rate, QBMP Company Name Designed By Company Project Number/Name Drainage Area Number/Name CORAL MOUNTAIN - MSA JOB #2553 DRAINAGE AREAS 'C' & 'F' January 26, 2021 VU (in-ac/ac) x AT (ac) x 43,560 (ft2/ac) 12(in/ft) Calculate the Composite Runoff Coefficient, C for the BMP Tributary Area Determine Design Storage Volume, VBMP ATRIB = 28.403 acres Determine the Impervious Area Within ATRIB (AIMP)AIMP = 14.157 acres Calculate the Impervious Area Ratio (IF) IF = AIMP/ATRIB IF = 0.50 Use the following equation based on the WEF/ASCE Method CBMP = 0.858If 3 - 0.78If 2 + 0.774If + 0.04 CBMP = 0.34 Calculate VU, the 80% Unit Storage Volume VU = 0.40 x CBMP VU = 0.14 (in*ac)/ac Calculate the design storage volume of the BMP, VBMP VBMP (ft3) =VBMP = 13,950 ft3 QBMP = CBMP x I x ATRIB QBMP = 1.92 ft3/s I = Design Rainfall Intensity, 0.2 in/hr Legend: Required Entries Calculated Cells Determine the Impervious Area Ratio Whitewater Watershed BMP Design Volume, VBMP & Design Flow Rate , QBMP (Rev. 06-2014) Enter the Area Tributary to this Feature (ATRIB) MSA Consulting, Inc DLS Date County/City Case No. Notes: BMP Design Flow Rate, QBMP Company Name Designed By Company Project Number/Name Drainage Area Number/Name CORAL MOUNTAIN - MSA JOB #2553 DRAINAGE AREA 'D' January 26, 2021 VU (in-ac/ac) x AT (ac) x 43,560 (ft2/ac) 12(in/ft) Calculate the Composite Runoff Coefficient, C for the BMP Tributary Area Determine Design Storage Volume, VBMP ATRIB = 61.802 acres Determine the Impervious Area Within ATRIB (AIMP)AIMP = 19.059 acres Calculate the Impervious Area Ratio (IF) IF = AIMP/ATRIB IF = 0.31 Use the following equation based on the WEF/ASCE Method CBMP = 0.858If 3 - 0.78If 2 + 0.774If + 0.04 CBMP = 0.23 Calculate VU, the 80% Unit Storage Volume VU = 0.40 x CBMP VU = 0.09 (in*ac)/ac Calculate the design storage volume of the BMP, VBMP VBMP (ft3) =VBMP = 20,610 ft3 QBMP = CBMP x I x ATRIB QBMP = 2.84 ft3/s I = Design Rainfall Intensity, 0.2 in/hr Notes: BMP Design Flow Rate, QBMP Company Name Designed By Company Project Number/Name Drainage Area Number/Name CORAL MOUNTAIN - MSA JOB #2553 DRAINAGE AREA 'E' January 26, 2021 VU (in-ac/ac) x AT (ac) x 43,560 (ft2/ac) 12(in/ft) Calculate the Composite Runoff Coefficient, C for the BMP Tributary Area Determine Design Storage Volume, VBMP Legend: Required Entries Calculated Cells Determine the Impervious Area Ratio Whitewater Watershed BMP Design Volume, VBMP & Design Flow Rate , QBMP (Rev. 06-2014) Enter the Area Tributary to this Feature (ATRIB) MSA Consulting, Inc DLS Date County/City Case No. ATRIB = 35.742 acres Determine the Impervious Area Within ATRIB (AIMP)AIMP = 10.635 acres Calculate the Impervious Area Ratio (IF) IF = AIMP/ATRIB IF = 0.30 Use the following equation based on the WEF/ASCE Method CBMP = 0.858If 3 - 0.78If 2 + 0.774If + 0.04 CBMP = 0.22 Calculate VU, the 80% Unit Storage Volume VU = 0.40 x CBMP VU = 0.09 (in*ac)/ac Calculate the design storage volume of the BMP, VBMP VBMP (ft3) =VBMP = 11,617 ft3 QBMP = CBMP x I x ATRIB QBMP = 1.60 ft3/s I = Design Rainfall Intensity, 0.2 in/hr Legend: Required Entries Calculated Cells Determine the Impervious Area Ratio Whitewater Watershed BMP Design Volume, VBMP & Design Flow Rate , QBMP (Rev. 06-2014) Enter the Area Tributary to this Feature (ATRIB) MSA Consulting, Inc DLS Date County/City Case No. 35 Notes: BMP Design Flow Rate, QBMP Company Name Designed By Company Project Number/Name Drainage Area Number/Name CORAL MOUNTAIN - MSA JOB #2553 DRAINAGE AREAS 'G' January 26, 2021 VU (in-ac/ac) x AT (ac) x 43,560 (ft2/ac) 12(in/ft) Calculate the Composite Runoff Coefficient, C for the BMP Tributary Area Determine Design Storage Volume, VBMP ATRIB = 7.118 acres Determine the Impervious Area Within ATRIB (AIMP)AIMP = 6.406 acres Calculate the Impervious Area Ratio (IF) IF = AIMP/ATRIB IF = 0.90 Use the following equation based on the WEF/ASCE Method CBMP = 0.858If 3 - 0.78If 2 + 0.774If + 0.04 CBMP = 0.73 Calculate VU, the 80% Unit Storage Volume VU = 0.40 x CBMP VU = 0.29 (in*ac)/ac Calculate the design storage volume of the BMP, VBMP VBMP (ft3) =VBMP = 7,547 ft3 QBMP = CBMP x I x ATRIB QBMP = 1.04 ft3/s I = Design Rainfall Intensity, 0.2 in/hr Legend: Required Entries Calculated Cells Determine the Impervious Area Ratio Whitewater Watershed BMP Design Volume, VBMP & Design Flow Rate , QBMP (Rev. 06-2014) Enter the Area Tributary to this Feature (ATRIB) MSA Consulting, Inc DLS Date County/City Case No. 35 Notes: BMP Design Flow Rate, QBMP Company Name Designed By Company Project Number/Name Drainage Area Number/Name CORAL MOUNTAIN - MSA JOB #2553 DRAINAGE AREAS 'H' January 26, 2021 VU (in-ac/ac) x AT (ac) x 43,560 (ft2/ac) 12(in/ft) Calculate the Composite Runoff Coefficient, C for the BMP Tributary Area Determine Design Storage Volume, VBMP ATRIB = 51.629 acres Determine the Impervious Area Within ATRIB (AIMP)AIMP = 15.164 acres Calculate the Impervious Area Ratio (IF) IF = AIMP/ATRIB IF = 0.29 Use the following equation based on the WEF/ASCE Method CBMP = 0.858If 3 - 0.78If 2 + 0.774If + 0.04 CBMP = 0.22 Calculate VU, the 80% Unit Storage Volume VU = 0.40 x CBMP VU = 0.09 (in*ac)/ac Calculate the design storage volume of the BMP, VBMP VBMP (ft3) =VBMP = 16,626 ft3 QBMP = CBMP x I x ATRIB QBMP = 2.29 ft3/s I = Design Rainfall Intensity, 0.2 in/hr Legend: Required Entries Calculated Cells Determine the Impervious Area Ratio Whitewater Watershed BMP Design Volume, VBMP & Design Flow Rate , QBMP (Rev. 06-2014) Enter the Area Tributary to this Feature (ATRIB) MSA Consulting, Inc DLS Date County/City Case No. 35 Notes: BMP Design Flow Rate, QBMP Company Name Designed By Company Project Number/Name Drainage Area Number/Name CORAL MOUNTAIN - MSA JOB #2553 DRAINAGE AREAS 'I' January 26, 2021 VU (in-ac/ac) x AT (ac) x 43,560 (ft2/ac) 12(in/ft) Calculate the Composite Runoff Coefficient, C for the BMP Tributary Area Determine Design Storage Volume, VBMP Coral Mountain Master Plan Hydrology Report Appendix H Existing Topography Exhibit Synthetic Unit Hydrograph Exhibits 58th Avenue NeighborhoodCommercial Future Low Density Residential (3) Future Low Density Residential (2) FutureLow Density Residential (4) Low Density Residential (5)MadisonStreet60th Avenue Low Density Residential (1) The Farm Surf Resort (5) Back of House Pop-Up Village 2 Planning Area IX Surf Resort (4) Surf Resort (1) Future Planning Area VII Planning Area VIII Planning Area VIIIPlanning Area VIII Planning Area VIII Planning Area VIII PA IX Planning Area IX The Beach Club Pop-Up Village 3 Pop-Up Village 4 Pop-Up Village 5 The Farm Village PA X Open Space Planning Area X Surf Resort (3) Planning Area IX Surf Resort (2) Planning Area IX Open Space The Hotel Pop-Up Village 1 The Hotel Coral Mountain MSA CONSULTING, INC. 34200 Bob Hope Drive, Rancho Mirage, CA 92270 760.320.9811 msaconsultinginc.com R:\2553\ACAD\Hydrology\2553 Existing Hydrology Exhibit.dwg, 10/21/2019 9:59:09 AM, dschulze, MSA Consulting, Inc. 58th Avenue NeighborhoodCommercial Future Low Density Residential (3) Future Low Density Residential (2) FutureLow Density Residential (4) Low Density Residential (5)MadisonStreet60th Avenue Low Density Residential (1) The Farm Surf Resort (5) Back of House Pop-Up Village 2 Planning Area IX Surf Resort (4) Surf Resort (1) Future Planning Area VII Planning Area VIII Planning Area VIII Planning Area VIII Planning Area VIII Planning Area VIII PA IX Planning Area IX The Beach Club Pop-Up Village 3 Pop-Up Village 4 Pop-Up Village 5 The Farm Village PA X Open Space Planning Area X Surf Resort (3) Planning Area IX Surf Resort (2) Planning Area IX Open Space The Hotel Pop-Up Village 1 The Hotel Coral Mountain DA-A1 L=1,180 A=88.412 DA-A3 L=1,050 A=24.968 DA-A2 L=1,050 A=17.314 DA-B L=2,000 A=41.586 DA-C L=1,350 A=10.191 DA-D L=780 A=28.403 DA-E L=780 A=61.802 DA-F A=44.811 DA-G A=35.742 DA-I A=51.629 DA-H A=7.118 DA-OFF (N) A=11.704 DA-OFF (S) A=5.701 MSA CONSULTING, INC. 34200 Bob Hope Drive, Rancho Mirage, CA 92270 760.320.9811 msaconsultinginc.com R:\2553\ACAD\Hydrology\Master Plan Hydrology\2553 Master Plan Hydrology Exhibit - SUH 01.dwg, 1/27/2021 6:38:47 AM, dschulze, MSA Consulting, Inc. MSA CONSULTING, INC. 34200 Bob Hope Drive, Rancho Mirage, CA 92270 760.320.9811 msaconsultinginc.com DRAINAGE AREA 'A1' DRAINAGE AREA 'A2' DRAINAGE AREA 'A3' DRAINAGE AREA 'A' DRAINAGE AREA 'B' DRAINAGE AREA 'C' DRAINAGE AREA 'D' DRAINAGE AREA 'E' DRAINAGE AREA 'F' DRAINAGE AREA 'G' DRAINAGE AREA 'H' DRAINAGE AREA 'I' DRAINAGE AREA OFF-SITE NORTH DRAINAGE AREA OFF-SITE SOUTH DRAINAGE AREAS 'C' & 'F'R:\2553\ACAD\Hydrology\Master Plan Hydrology\2553 Master Plan Hydrology Exhibit - SUH 02.dwg, 1/27/2021 6:39:31 AM, dschulze, MSA Consulting, Inc.