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31116 (2)uu .--_--_IE -- ---_ -_/ ., For Property Located at the southeast corner of Washington St. and Miles Ave. City of La Quinta, California A�LProvecl with RoUgh GrMcling PI&N 1 1 M/56 CENTRE POINTE PARCEL MAP NO. 31116 QRpFESSio QUO p. O E Lq !F� NO. 43880 September 15, 2004 Prepared for Alf pF C Al\F4� CENTRE POINTE, LL IDPLANINING IN CIVIL IENGINTIIRING IN LAND SURVEYING 34200 BOB HOPE Dawc ■ RANG -10 MIRAGE ■ CA 92270 r �'" ' .C! ��e i �Fv Ji i4 Q/ 1 � Table of Contents A. Narrative B. Fema Map C. Short-cut Synthetic Unit Hydrograph Calculations for Existing Runoff Conditions D. Existing Conditions — Rational Method (10 8100 Year Storm) E. Proposed Conditions — Rational Method (10 8100 Year Storm) F. CVWD Letter, dated 2/20/04 G. Existing Hydrology Map H. Proposed Hydrology Map I. Rough Grading Plan, dated i• .y • 6- C Notes soIntroduction Centre Pointe (Parcel Map No. 31116) is located at the southeast corner of Washington Street and Miles Avenue, also situated in the south half of Section 19, Township 5 South, Range 7 East, San Bernardino Meridian (see Index Map on Rough Grading Plan). Existing Conditions The Flood Insurance Rate Map (FIRM) Panel 060709 0005 B, Map Revised August 19, 1991, for Riverside County, prepared by the Federal Emergency Management Agency (FEMA), designates the entire site as Zone X, indicating areas determined to be outside 500 -year flood plain (see FEMA Map). The project site does not receive significant offsite flows. Offsite flows approaching the project will tend to be directed south along the west side of Washington Street, and east along the north side of Miles Avenue. As shown on the Existing Hydrology Map, some areas drain off the site, and some areas drain to retention areas within the site. Peak flows and runoff volumes have been calculated and are shown on the Map. Runoff volumes are based on the 3 -hour, 100 -year storm. Existing Retention Basin Area (ac.) Runoff (Vol.) Max. W.S. 1 8.85 0.90 ac -ft 102.0 2 13.63 1.39 ac -ft 101.0 3 2.27 0.23 ac -ft 99.0 Hydrology Requirements The City of La Quinta and the Coachella Valley Water District (CVWD) have flood control jurisdiction for this site. Per a CVWD letter dated 2/20/04 (copy attached), the project may direct project runoff to the existing Whitewater River Storm Water Channel. CVWD is the agency responsible for operation and • maintenance of the Whitewater River Storm Water Channel. Hydrologic Methods The Synthetic Unit Hydrograph, Shortcut Method, as prescribed in the 1978 Riverside County Flood Control & Water Conservation District Hydrology Manual, was used to determine the volume of storm runoff in the 100 -year storm. The 3 -hour, 6 -hour and 24 -hour storms were analyzed, with the 3 -hour storm producing the maximum runoff (see attached Runoff Volume Calculations). The data used in the Synthetic Unit Hydrograph calculations are as follows: Soil Group: D Runoff Index (RI) Number: 73 (Existing Good Cover) Storm Frequency: 100 -Year, 3 -Hour Total Adjusted Storm: 2.2 inches Impervious Area: 10% (Existing Areas) Constant Loss Rate (Fp): 0.33 inches /hour (Existing Areas) Low Loss Rate: 90% of rainfall (Existing Areas) Proposed Flood Control Improvements The Proposed Hydrology Map illustrates the tributary areas that drain to the proposed catch basins. Elevations were extracted from Rough Grading Plans (copy attached). As depicted on the map, all storm water runoff will be collected and conveyed in the streets to catch basins and, subsequently, via pipelines to the Whitewater Channel. An approval letter from CVWD has been requested. The proposed condition • produces a slight increase in the peak flow rate at the Washington Street catch basin. The proposed • condition produces a slight decrease in the peak flow rate at the easterly boundary on Miles Avenue. Within this proposed Parcel Map is Tentative Tract Map 32371 located in the easterly portion of the site. Results and Conclusion The Rational Method analysis indicates that the 100 -year storm will remain within the limits of the proposed public utility and drainage easements while the 10 -year storm will remain below top -of -curb levels. It is concluded therefore that the Centre Pointe project, Parcel Map 31116, meets the hydrologic requirements set forth by the City of La Quinta and CVWD. • • 1< -Z rl • Notes • • 0 FEMA MAP 2 IntraN!W Viewer [0607090005B.tifJ RNWI Vr's� digital east Ie z'�...00mw n1 Pa Zoom In Loom ou 1:'1 M. 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K w iI f i n II -- RO 'aJN i���u L G 1-3 -3 Notes • SHORT -CUT SYNTHETIC UNIT HYDROGRAPH CALCULATIONS for EXISTING RUNOFF VOLUMES i W • • R C F C& W C D HYDROLOGY MANUAL "SHORTCUT METHOD" SYNTHETIC UNIT HYDROGRAPH METHOD Unit Hydrograph and Effective Rain Calculation Form Project 1612 Existing Net rain 100 yr. 3 hr. Sheet 1 of 1 By JAD_ Date Checked Date (11 CONCENTRATION POINT 0.000 [3] DRAINAGE AREA -SQ ACRES 1.000 [5] UNIT TIME - MINUTES 10.000 171 UNIT TIME - PERCENT OF LAG (100'[5]/[6]) 0.000 [9] STORM FREQUENCY & DURATION 100 YEAR- 3 HOUR [11] VARIABLE LOSS RATE (AVG }INCHES /HOUR 0.000 [131 CONSTANT LOSS RATE- INCHES /HOUR 0.330 (21 AREA DESIGNATION [41 ULTIMATE DISCHARGE - CFS - HRS /IN (645'[3]) 0.000 [6] LAG TIME - MINUTES 0.000 181 S -CURVE 0.000 [101 TOTAL ADJUSTED STORM RAIN- INCHES 2.200 [12] MINIMUM LOSS RATE (FOR VAR. LOSS) -IN /HR 0.000 [141 LOW LOSS RATE- PERCENT 90.000 UNIT HYDROGRAPH EFFECTIVE RAIN FLOOD HYDROGRAPH [15] UNIT TIME PERIOD m [161 TIME PERCENT OF LAG [7]•[15] [171 CUMULATIVE AVERAGE PERCENT OF ULTIMATE DISCHARGE (S- GRAPH) [16] DISTRIB GRAPH PERCENT [17]m- [17]m -1 [171 UNIT HYDROGRAPH CFS - HRS /IN 4 • 18 100.000 1201 PATTERN PERCENT (PL E -5.9) [211 STORM RAIN IN /HR 60[101[201 100[5] [221 LOSS RATE IN /HR [231 EFFECTIVE RAIN IN /HR [21] -[22] [24] FLOW CFS MAX LOW 1.000 2.600 0.343 0.330 0.309 0.034 0.035 2.000 2.600 0.343 0.330 0.309 0.034 0.035 3.000 3.300 0.436 0.330 0.392 0.106 0.106 4.000 3.300 0.436 0.330 0.392 0.106 0.106 5.000 3.300 0.436 0.330 0.392 0.106 0.106 6.000 3.400 0.449 0.330 0.404 0.119 0.120 7.000 4.400 0.581 0.330 0.523 0.251 0.253 8.000 4.200 0.554 0.330 0.499 0.224 0.226 9.000 5.300 0.700 0.330 0.630 0.370 0.373 10.000 5.100 0.673 0.330 0.606 0.343 0.346 11.000 6.400 0.845 0.330 0.760 0.515 0.519 12.000 5.900 0.779 0.330 0.7011 0.449 0.453 13.000 7.300 0.964 0.330 0.867 0.634 0.639 14.000 8.500 1.122 0.330 1.010 0.792 0.799 15.000 14.100 1.861 0.330 1.675 1.531 1.544 16.000 14.100 1.861 0.330 1.675 1.531 1.544 17.000 3.800 0.502 0.330 0.451 0.172 0.173 18.000 2.400 0.317 0.330 0.285 0.032 0.032 TOTALS 1004000 7.3471 7.408 • EFFECTIVE RAIN = 1.225 INCHES C- • • R C F C& W C D HYDROLOGY MANUAL "SHORTCUT METHOD" SYNTHETIC UNIT HYDROGRAPH METHOD Unit Hydrograph and Effective Rain Calculation Form Project 1612 Existing Net rain 100 yr. 6 hr. Sheet 1 of 1 By JAD Date Checked Date [1] CONCENTRATION POINT 0.000 [3] DRAINAGE AREA -SO ACRES 1.000 [51 UNIT TIME - MINUTES 15.000 [7] UNIT TIME - PERCENT OF LAG (100'[51/[6]) 0.000 [9] STORM FREQUENCY & DURATION 100 year 6 hour [11] VARIABLE LOSS RATE (AVG)- INCHES /HOUR 0.000 13 CONSTANT LOSS RATE- INCHES /HOUR 0.330 [2] AREA DESIGNATION [4] ULTIMATE DISCHARGE - CFS - HRS /IN (645'[3]) 0.000 [61 LAG TIME - MINUTES 0.000 [8] S -CURVE 0.000 [101 TOTAL ADJUSTED STORM RAIN- INCHES 2.500 [12] MINIMUM LOSS RATE (FOR VAR. LOSS) -IN /HR 0.000 [141 LOW LOSS RATE- PERCENT 90.000 UNIT HYDROGRAPH EFFECTIVE RAIN FLOOD HYDROGRAPH [15] UNIT TIME PERIOD m [161 TIME PERCENT OF LAG [7]'[15] [171 CUMULATIVE AVERAGE PERCENT OF ULTIMATE DISCHARGE (S- GRAPH) [16) DISTRIB GRAPH PERCENT [17]m [17]m -1 [171 UNIT HYDROGRAPH CFS - HRS /IN [41*[181 100.000 [201 PATTERN PERCENT (PL E -5.9) [21] STORM RAIN IN /HR 60 1f ON201 100[5] [22] LOSS RATE IN /HR [23] EFFECTIVE RAIN IN /HR [21] -[22] [24) FLOW CFS MAX LOW 1.000 1.700 0.170 0.330 0.153 0.017 0.017 2.000 1.900 0.190 0.330 0.171 0.019 0.019 3.000 2.100 0.210 0.330 0.189 0.021 0.021 4.000 2.200 0.220 0.330 0.198 0.022 0.022 5.000 2.400 0.240 0.330 0.2161 0.024 0.024 6.000 2.400 0.240 0.330 0.216 0.024 0.024 7.000 2.400 0.240 0.330 0.216 0.024 0.024 8.000 2.500 0.250 0.330 0.225 0.025 0.025 9.000 2.600 0.260 0.330 0.234 0.026 0.026 10.000 2.700 0.270 0.330 0.243 0.027 0.027 11.000 2.800 0.280 0.330 0.252 0.028 0.028 12.000 3.000 0.300 0.330 0.270 0.030 0.030 13.000 3.200 0.320 0.330 0.288 0.032 0.032 14.000 3.600 0.360 0.330 0.324 0.036 0.036 15.000 4.300 0.430 0.330 0.387 0.100 0.101 16.000 4.700 0.470 0.330 0.423 0.140 0.141 17.000 5.400 0.5401 0.330 0.486 0.210 0.212 18.000 6.200 0.620 0.330 0.558 0.290 0.292 19.000 6.900 0.690 0.330 0.621 0.360 0.363 20.000 7.500 0.750 0.330 0.675 0.420 0.423 21.000 10.600 1.060 0.330 0.954 0.730 0.736 22.000 14.500 1.450 0.330 1.305 1.120 1.129 23.000 3.400 0.340 0.330 0.306 0.034 0.034 24.000 1.0001 0.100 0.330 0.090 0.010 0.010 TOTALS 1 100.0001 1 3.7691 3.800 • EFFECTIVE RAIN = 0.942 INCHES C--2 n • R C F C& W C D HYDROLOGY MANUAL "SHORTCUT METHOD" SYNTHETIC UNIT HYDROGRAPH METHOD Unit Hydrograph and Effective Rain Calculation Form Project 1612 Existing Net rain 100 yr. 24 hr. Sheet 1 of 1 By JAD Date Checked Date [11 CONCENTRATION POINT 0.000 [3] DRAINAGE AREA -SQ ACRES 1.000 [5] UNIT TIME - MINUTES 60.000 [71 UNIT TIME - PERCENT OF LAG (100'[5]/[6]) 0.000 [9] STORM FREQUENCY & DURATION 100 YEAR- 24 HOUR [111 VARIABLE LOSS RATE (AVG }INCHES /HOUR 0.000 031 CONSTANT LOSS RATE- INCHES /HOUR 0.330 121 AREA DESIGNATION [4] ULTIMATE DISCHARGE - CFS - HRS /IN (645'[3]) 0.000 [6] LAG TIME - MINUTES 0.000 [81 S -CURVE 0.000 [10] TOTAL ADJUSTED STORM RAIN- INCHES 4.000 [121 MINIMUM LOSS RATE (FOR VAR. LOSS) -IN /HR 0.000 [141 LOW LOSS RATE- PERCENT 90.000 UNIT HYDROGRAPH EFFECTIVE RAIN FLOOD HYDROGRAPH [15] UNIT TIME PERIOD m [161 TIME PERCENT OF LAG [7]'[15] [17] CUMULATIVE AVERAGE PERCENT OF ULTIMATE DISCHARGE (S- GRAPH) [16] DISTRIB GRAPH PERCENT [17]m- [17]m -1 [17] UNIT HYDROGRAPH CFS - HRS /IN 4.18 100.000 [20] PATTERN PERCENT (PL E -5.9) [21] STORM RAIN IN /HR 60[101[201 100[5] [221 LOSS RATE IN/HR [23] EFFECTIVE RAIN IN /HR [211-[221 [24) FLOW CFS MAX LOW 1.000 1.200 0.048 0.330 0.043 0.005 0.005 2.000 1.300 0.052 0.330 0.047 0.005 0.005 3.000 1.800 0.072 0.330 0.065 0.007 0.007 4.000 2.100 0.084 0.330 0.076 0.008 0.008 5.000 2.800 0.112 0.330 0.1011 0.011 0.011 6.000 2.900 0.116 0.330 0.1041 0.012 0.012 7.000 3.800 0.152 0.330 0.1371 0.015 0.015 8.000 4.600 0.184 0.330 0.1661 0.018 0.019 9.000 6.300 0.252 0.330 0.227 0.025 0.025 10.000 8.200 0.328 0.330 0.295 0.033 0.033 11.000 7.000 0.280 0.330 0.252 0.028 0.028 12.000 7.300 0.292 0.330 0.263 0.029 0.029 13.000 10.800 0.432 0.330 0.389 0.102 0.103 14.000 11.400 0.456 0.330 0.410 0.126 0.127 15.000 10.400 0.416 0.330 0.374 0.086 0.087 16.000 8.500 0.340 0.330 0.3061 0.034 0.034 17.000 1.400 0.056 0.330 0.050 0.006 0.006 18.000 1.900 0.076 0.330 0.068 0.008 0.008 19.000 1.300 0.052 0.330 0.047 0.005 0.005 20.000 1.200 0.048 0.330 0.043 0.005 0.005 21.000 1.100 0.044 0.330 0.040 0.004 0.004 22.000 1 1.000 0.040 0.330 0.036 0.004 0.004 23.000 0.900 0.036 0.330 0.032 0.004 0.004 24.000 0.800 0.032 0.330 0.029 0.003 0.003 TOTALS 1 100.0001 0.5841 0.588 0 EFFECTIVE RAIN = 0.584 INCHES C-3 • • • Q Notes • • "EXISTING CONDITIONS" RATIONAL METHOD ANALYSIS 100 -YEAR STORM • M Riverside County Rational Hydrology Program CIVILCADD /CIVILDESIGN Engineering Software,(c) 1989 - 2001 Version 6.4 Rational Hydrology Study Date: 05/11/04 File:1612e.out ------------------------------------------------------------------------ Project 1612 100 Year Storm Existing Conditions ----------------------------------------------------------- ********* Hydrology Study Control Information * * * * * * * * ** English (in -lb) Units used in input data file ----------------------------------------------------------- Mainiero, Smith and Associates, Inc. - SIN 931 Rational Method Hydrology Program based on Riverside County Flood Control & Water Conservation District 1978 hydrology manual Storm event (year) = 100.00 Antecedent Moisture Condition = 3 Standard intensity- duration curves data (Plate D -4.1) For the [ Palm Springs ) area used. 10 year storm 10 minute intensity = 2.830(In /Hr) 10 year storm 60 minute intensity = 1.000(In /Hr) 100 year storm 10 minute intensity = 4.520(In /Hr) 100 year storm 60 minute intensity = 1.600(In /Hr) Storm event year = 100.0 Calculated rainfall intensity data: 1 hour intensity = 1.600(ln /Hr) Slope of intensity duration curve = 0.5800 +++++++++++++++++++++++++++++++++++++++ + + ++ + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 101.000 to Point /Station 102.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 117.800(Ft.) Bottom (of initial area) elevation = 93.000(Ft.) Difference in elevation = 24.800(Ft.) Slope = 0.02480 s(percent)= 2.48 TC = k(0.300) *[(length "3) /(elevation change) ]A0.2 Initial area time of concentration = 9.959 min. Rainfall intensity = 4.534(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.881 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 52.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 5.351(CFS) Total initial stream area = 1.340(AC.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + ++ + + + + + + + + + + + + ++ + + + + + + ++ Process from Point /Station 102.000 to Point /Station 103.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** • Top of street segment elevation = 93.000(Ft.) End of street segment elevation = 85.000(Ft.) D-2 +++++++++++++++++++++++++++++++++++++++ + + + ++ + + +++ + + + + ++ ++ + ++ + + + + + + + +++ Process from Point /Station 201.000 to Point /Station 202.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 115.000(Ft.) Bottom (of initial area) elevation = 88.000(Ft.) Difference in elevation = 27.000(Ft.) Slope = 0.02700 s(percent)= 2.70 TC = k(0.940) *[(length^3) /(elevation change))'0.2 Initial area time of concentration = 30.680 min. Rainfall intensity = 2.361(In /Hr) for a 100.0 year storm UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.639 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 58.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 3.408(CFS) Total initial stream area = 2.260(Ac.) Pervious area fraction = 1.000 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + ++ + + + + + + + + + + + + + ++ + + ++ Process from Point /Station 202.000 to Point /Station 203.000 * * ** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION * * ** Top of natural channel elevation = 88.000(Ft.) • End of natural channel elevation = 77.000(Ft.) Length of natural channel = 250.000(Ft.) Estimated mean flow rate at midpoint of channel = 4.396(CFS) © -3 Length of street segment = 430.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 43.000(Ft.) Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on [1J side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 6.270(CFS) Depth of flow = 0.383(Ft.), Average velocity = 3.539(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 12.826(Ft.) Flow velocity = 3.54(Ft /s) Travel time = 2.03 min. TC = 11.98 min. Adding area flow to street COMMERCIAL subarea type Runoff Coefficient = 0.879 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 52.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 4.072(In /Hr) for a 100.0 year storm Subarea runoff = 1.647(CFS) for 0.460(Ac.) Total runoff = 6.998(CFS) Total area = 1.800(Ac.) Street flow at end of street = 6.998(CFS) Half street flow at end of street = 6.998(CFS) Depth of flow = 0.395(Ft.), Average velocity = 3.633(Ft/s) Flow width (from curb towards crown)= 13.415(Ft.) +++++++++++++++++++++++++++++++++++++++ + + + ++ + + +++ + + + + ++ ++ + ++ + + + + + + + +++ Process from Point /Station 201.000 to Point /Station 202.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 115.000(Ft.) Bottom (of initial area) elevation = 88.000(Ft.) Difference in elevation = 27.000(Ft.) Slope = 0.02700 s(percent)= 2.70 TC = k(0.940) *[(length^3) /(elevation change))'0.2 Initial area time of concentration = 30.680 min. Rainfall intensity = 2.361(In /Hr) for a 100.0 year storm UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.639 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 58.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 3.408(CFS) Total initial stream area = 2.260(Ac.) Pervious area fraction = 1.000 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + ++ + + + + + + + + + + + + + ++ + + ++ Process from Point /Station 202.000 to Point /Station 203.000 * * ** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION * * ** Top of natural channel elevation = 88.000(Ft.) • End of natural channel elevation = 77.000(Ft.) Length of natural channel = 250.000(Ft.) Estimated mean flow rate at midpoint of channel = 4.396(CFS) © -3 Natural valley channel type used L.A. County flood control district formula for channel velocity: Velocity(ft /s) _ (7 + 8(q(English Units)^.352)(slope "0.5) Velocity using mean channel flow = 4.29(Ft /s) Correction to map slope used on extremely rugged channels with drops and waterfalls (Plate D -6.2) Normal channel slope = 0.0440 Corrected /adjusted channel slope = 0.0440 Travel time = 0.97 min. TC = 31.65 min. Adding area flow to channel UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.635 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 58.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 2.319(In /Hr) for a 100.0 year storm Subarea runoff = 1.930(CFS) for 1.310(Ac.) Total runoff = 5.338(CFS) Total area = 3.570(Ac.) +++++++++++++++++++++++++++++++++++++++ + + + ++ + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 301.000 to Point /Station 302.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 115.000(Ft.) Bottom (of initial area) elevation = 104.000(Ft.) Difference in elevation = 11.000(Ft.) Slope = 0.01100 s(percent)= 1.10 TC = k (0.940) *[(length"3) /( elevation change)] "0.2 Initial area time of concentration = 36.715 min. Rainfall intensity = 2.127(In /Hr) for a 100.0 year storm UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.619 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 58.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 6.795(CFS) Total initial stream area = 5.160(Ac.) Pervious area fraction = 1.000 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + ++ + + ++ + + + + ++ + + + + ++ Process from Point /Station 302.000 to Point /Station 303.000 * * ** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION * * ** Top of natural channel elevation = 104.000(Ft.) End of natural channel elevation = 76.000(Ft.) Length of natural channel = 500.000(Ft.) Estimated mean flow rate at midpoint of channel = 9.291(CFS) Natural valley channel type used L.A. County flood control district formula for channel velocity: Velocity(ft /s) _ (7 + 8(q(English Units) ".352)(slope "0.5) Velocity using mean channel flow = 5.81(Ft /s) Correction to map slope used on extremely rugged channels with drops and waterfalls (Plate D -6.2) Normal channel slope = 0.0560 Corrected /adjusted channel slope = 0.0560 Travel time = 1.44 min. TC = 38.15 min. • 's • Adding area flow to channel UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.615 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 58.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 2.081(In /Hr) for a 100.0 year storm Subarea runoff = 4.847(CFS) for 3.790(Ac.) Total runoff = 11.642(CFS) Total area = 8.950(Ac.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 401.000 to Point /Station 402.000 * * ** INITIAL AREA EVALUATION * * ** +++++++++++++++++++++++++++++++++++++++ + + + + ++ + + + + + + + + + + + ++ + + ++ + + + + + + ++ Process from Point /Station 402.000 to Point /Station 403.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** Top of street segment elevation = 113.000(Ft.) End of street segment elevation = 99.800(Ft.) Length of street segment = 1120.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 43.000(Ft.) Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 5.345(CFS) Depth of flow = 0.391(Ft.), Average velocity = 2.863(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 13.192(Ft.) Flow velocity = 2.86(Ft /s) Travel time = 6.52 min. TC = 20.35 min. Adding area flow to street • COMMERCIAL subarea type Runoff Coefficient = 0.874 Decimal fraction soil group A = 1.000 D -5 Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 117.800(Ft.) Bottom (of initial area) elevation = 113.000(Ft.) Difference in elevation = 4.800(Ft.) Slope = 0.00480 s(percent)= 0.48 TC = k(0.300) *[(length "3) /(elevation change)]"0.2 Initial area time of concentration = 13.832 min. Rainfall intensity = 3.747(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.878 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 • RI index for soil(AMC 3) 52.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 initial subarea runoff = 3.520(CFS) Total initial stream area = 1.070(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + ++ + + + + + + + + + + + ++ + + ++ + + + + + + ++ Process from Point /Station 402.000 to Point /Station 403.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** Top of street segment elevation = 113.000(Ft.) End of street segment elevation = 99.800(Ft.) Length of street segment = 1120.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 43.000(Ft.) Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 5.345(CFS) Depth of flow = 0.391(Ft.), Average velocity = 2.863(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 13.192(Ft.) Flow velocity = 2.86(Ft /s) Travel time = 6.52 min. TC = 20.35 min. Adding area flow to street • COMMERCIAL subarea type Runoff Coefficient = 0.874 Decimal fraction soil group A = 1.000 D -5 Y-b Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 52.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 2.995(In /Hr) for a 100.0 year storm Subarea runoff = 2.905(CFS) for 1.110(Ac.) Total runoff = 6.425(CFS) Total area = 2.180(Ac.) Street flow at end of street = 6.425(CFS) Half street flow at end of street = 6.425(CFS) Depth of flow = 0.411(Ft.), Average velocity = 2.992(Ft/s) Flow width (from curb towards crown)= 14.215(Ft.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + ++ + + + + + + +++ + + + + + + + ++ Process from Point /Station 501.000 to Point /Station 502.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 900.000(Ft.) Top (of initial area) elevation = 112.000(Ft.) Bottom (of initial area) elevation = 97.000(Ft.) Difference in elevation = 15.000(Ft.) Slope = 0.01667 s(percent)= 1.67 TC = k (0.940) *[(length ^3) /(elevation change)1^0.2 Initial area time of concentration = 32.393 min. Rainfall intensity = 2.288(In /Hr) for a 100.0 year storm UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.633 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 58.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 7.862(CFS) Total initial stream area = 5.430(Ac.) Pervious area fraction = 1.000 +++++++++++++++++++++++++++++++++++++++ + + + + + ++ + + + + + + + + + + +++ + + + + + + + + + ++ Process from Point /Station 502.000 to Point /Station 503.000 * * ** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION * * ** Top of natural channel elevation = 97.000(Ft.) End of natural channel elevation = 78.000(Ft.) Length of natural channel = 500.000(Ft.) Estimated mean flow rate at midpoint of channel = 8.781(CFS) Natural valley channel type used L.A. County flood control district formula for channel velocity: Velocity(ft /s) _ (7 + 8(q(English Units) ".352)(slope°0.5) Velocity using mean channel flow = 4.72(Ft /s) Correction to map slope used on extremely rugged channels with drops and waterfalls (Plate D -6.2) Normal channel slope = 0.0380 Corrected /adjusted channel slope = 0.0380 Travel time = 1.77 min. TC = 34.16 min. Adding area flow to channel UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.627 Decimal fraction soil group A ='1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 3) = 58.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 2.218(In /Hr) for a 100.0 year storm Subarea runoff = 1.767(CFS) for 1.270(Ac.) Y-b Total runoff = 9.628(CFS) Total area = 6.700(Ac.) End of computations, total study area = 23.20 (Ac.) The following figures may be used for a unit hydrograph study of the same area. Area averaged pervious area fraction(Ap) = 0.846 Area averaged RI index number = 37.0 • • • "EXISTING CONDITIONS" RATIONAL METHOD ANALYSIS 10 -YEAR STORM • IWO • Riverside County Rational Hydrology Program CIVILCADD /CIVILDESIGN Engineering Software,(c) 1989 - 2001 Version 6.4 .Rational Hydrology Study Date: 05/11/04 File:1612e.out ------------------------------------------------------------------------ Project 1612 10 Year Storm Existing Conditions ------------------------------------------------------------------------ ********* Hydrology Study Control Information * * * * * * * * ** English (in -lb) Units used in input data file ------------------------------------------------------------------------ Mainiero, Smith and Associates, Inc. - SIN 931 ------------------------------------------------------------------------ Rational Method Hydrology Program based on Riverside County Flood Control & Water Conservation District 1978 hydrology manual Storm event (year) = 10.00 Antecedent Moisture Condition = 2 Standard intensity- duration curves data (Plate D -4.1) For the [ Palm Springs ) area used. 10 year storm 10 minute intensity = 2.830(In /Hr) 10 year storm 60 minute intensity = 1.000(In /Hr) 100 year storm 10 minute intensity = 4.520(In /Hr) 100 year storm 60 minute intensity = 1.600(In /Hr) Storm event year = 10.0 Calculated rainfall intensity data: 1 hour intensity = 1.000(In /Hr) Slope of intensity duration curve = 0.5800 +++++++++++++++++++++++++++++++++++++++ + + + + +++ + ++ + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 101.000 to Point /Station 102.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 117.800(Ft.) Bottom (of initial area) elevation = 93.000(Ft.) Difference in elevation = 24.800(Ft.) Slope = 0.02480 s(percent)= 2.48 TC = k(0.300) *[(length "3) /(elevation change))"0.2 Initial area time of concentration = 9.959 min. Rainfall intensity = 2.834(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.855 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = ,0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 2) = 32.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 3.247(CFS) Total initial stream area = 1.340(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ ++ + + + + + + + + + ++ + + + + + + + + + + + + + + + +++ Process from Point /Station 102.000 to Point /Station 103.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** • Top of street segment elevation = 93.000(Ft.) End of street segment elevation = 85.000(Ft.) WO Length of street segment = 430.000(Ft.) • Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) 43.000(Ft.) Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on [1] side(s) cf the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 3.804(CFS) Depth of flow = 0.335(Ft.), Average velocity = 3.148(Ft /s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 10.400(Ft.) Flow velocity = 3.15(Ft /s) Travel time = 2.28 min. TC = 12.24 min. Adding area flow to street COMMERCIAL subarea type Runoff Coefficient = 0.852 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 2) = 32.00 Pervious area fraction = 0.10D; Impervious fraction = 0.900 Rainfall intensity = 2.515(In /Hr) for a 10.0 year storm Subarea runoff = 0.986(CFS) for 0.460(Ac.) Total runoff = 4.233(CFS) Total area = 1.800(AC.) Street flow at end of street = 4.233(CFS) Half street flow at end of street = 4.233(CFS) • Depth of flow = 0.344(Ft.), Average velocity = 3.227(Ft/s) Flow width (from curb towards crown)= 10.885(Ft.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + ++ + + + + + + + ++ + + + + + + + ++ Process from Point /Station 201.000 to Point /Station 202.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 115.000(Ft.) Bottom (of initial area) elevation = 88.000(Ft.) Difference in elevation = 27.000(Ft.) Slope = 0.02700 s(percent)= 2.70 TC = k(0.940) *[(length "3) /(elevation change)] ^0.2 Initial area time of concentration = 30.680 min. Rainfall intensity = 1.476(In /Hr) for a 10.0 year storm UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.364 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 2) = 38.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 1.213(CFS) Total initial stream area = 2.260(Ac.) Pervious area fraction = 1.00D +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 202.000 to Point /Station 203.000 * * ** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION * * ** Top of natural channel elevation = 88.000(Ft.) End of natural channel elevation = 77.000(Ft.) Length of natural channel = 250.000(Ft.) Estimated mean flow rate at midpoint of channel 1.564(CFS) MW 0 Natural valley channel type used L.A. County flood control district formula for channel velocity: Velocity(ft /s) = (7 + 8(q(English Units) ".352)(slope "0.5) Velocity using mean channel flcw = 3.43(Ft /9) Correction to map slope used on extremely rugged channels with drops and waterfalls (Plate D -6.2) Normal channel slope = 0.0440 Corrected /adjusted channel slope = 0.0440 Travel time = 1.21 min. TC = 31.89 min. Adding area flow to channel UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.359 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 2) = 38.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 1.443(In /Hr) for a 10.0 year storm Subarea runoff = 0.678(CFS) for 1.310(Ac.) Total runoff = 1.891(CFS) Total area = 3.570(Ac.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + +++ + + + + + + + + + + ++ + + + + + ++ Process from Point /Station 301.000 to Point /Station 302.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 115.000(Ft.) Bottom (of initial area) elevation = 104.000(Ft.) Difference in elevation = 11.000(Ft.) 0 Slope = 0.01100 s(percent)= 1.10 TC = k(0.940) *[(length "3) /(elevation change))"0.2 Initial area time of concentration = 36.715 min. Rainfall intensity = 1.330(In /Hr) for a 10.0 year storm UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.341 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 2) = 38.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 2.342(CFS) Total initial stream area = 5.160(Ac.) Pervious area fraction = 1.000 +++++++++++++++++±+++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 302.000 to Point /Station 303.000 * * ** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION * * ** Top of natural channel elevation = 104.000(Ft.) End of natural channel elevation = 76.000(Ft.) Length of natural channel = 500.000(Ft.) Estimated mean flow rate at midpoint of channel = 3.202(CFS) Natural valley channel type used L.A. County flood control district formula for channel velocity: Velocity(ft /s) = (7 + 8(q(English Units)'.352)(slopeA0.5) Velocity using mean channel flow = 4.51(Ft /s) Correction to map slope used on extremely rugged channels with drops and waterfalls (Plate D -6.2) Normal channel slope = 0.0560 Corrected /adjusted channel slope = 0.0560 Travel time = 1.85 min. TC = 38.56 min. M • Adding area flow to channel Width of half street (curb to crown) = UNDEVELOPED (good cover) subarea Distance from crown to crossfall grade Runoff Coefficient = 0.335 Slope from gutter to grade break (v /hz) Decimal fraction soil group A = 1.000 Slope from grade break to crown (v /hz) Decimal fraction soil group B = 0.000 Street flow is on [1) side(s) of the street Decimal fraction soil group C = 0.000 Distance from curb to property line = Decimal fraction soil group D = 0.000 Slope from curb to property line (v /hz) RI index for soil(AMC 2) = 38.00 Gutter width = 2.000(Ft.) Pervious area fraction = 1.000; impervious fraction = 0.000 Gutter hike from flowline = 2.000(In.) Rainfall intensity = 1.292(In /Hr) for a 10.0 year storm Manning's N in gutter = 0.0150 Subarea runoff = 1.643(CFS) for 3.790(Ac.) Total runoff = 3.985(CFS) Total area = 8.950(AC.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + ++ + + + + + + + + + + + ++ + + + + + + + ++ Process from Point /Station 401.000 to Point /Station 402.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = ' 117.800(Ft.) Bottom (of initial area) elevation = 113.000(Ft.) Difference in elevation = 4.800(Ft.) Slope = 0.00480 s(percent)= 0.48 TC = k(0.300) *[(length^3) /(elevation change)) ^0.2 Initial area time of concentration = 13.832 min. Rainfall intensity = 2.342(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.851 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 • RI index for soil(AMC 2) = 32.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 2.132(CFS) Total initial stream area = 1.070(AC.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 402.000 to Point /Station 403.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** Top of street segment elevation = 113.000(Ft End of street segment elevation = 99.800(Ft Length of street segment = 1120.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 43.000(Ft.) Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on [1) side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 3.238(CFS) Depth of flow = 0.341(Ft.), Average velocity = 2.545(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 10.703(Ft.) Flow velocity = 2.54(Ft /s) Travel time = 7.33 min. TC = 21.17 min. Adding area flow to street COMMERCIAL subarea type Runoff Coefficient = 0.845 Decimal fraction soil group A = 1.000 D -12 -D- 13 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 2) = 32.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 1.830(In /Hr) for a 10.0 year storm Subarea runoff = 1.717(CFS) for 1.110(Ac.) Total runoff = 3.849(CFS) Total area = 2.180(Ac.) Street flow at end of street = 3.849(CFS) Half street flow at end of street = 3.849(CFS) Depth of flow = 0.357(Ft.), Average velocity = 2.649(Ft/s) Flow width (from curb towards crown)= 11.516(Ft:) +++++++++++++++++++++++++++++++++++++++ + + + + + + + ++ + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 501.000 to Point /Station 502.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 900.000(Ft.) Top (of initial area) elevation = 112.000(Ft.) Bottom (of initial area) elevation = 97.000(Ft.) Difference in elevation = 15.000(Ft.) Slope = 0.01667 s(percent)= 1.67 TC = k(0.940) *[(length "3) /(elevation change)]'0.2 Initial area time of concentration = 32.393 min. Rainfall intensity = 1.430(In /Hr) for a 10.0 year storm UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.357 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 2) = 38.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 • Initial subarea runoff = 2.771(CFS) Total initial stream area = 5.430(Ac.) Pervious area fraction = 1.000 +++++++++++++++++++++++++++++++++++++++ + + + + + + + ++ + ++ + + + + + + + + + + ++ + + ++ + ++ Process from Point /Station 502.000 to Point /Station 503.000 * * ** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION * * ** Top of natural channel elevation = 97.000(Ft.) End of natural channel elevation = 78.000(Ft.) Length of natural channel = 500.000(Ft.) Estimated mean flow rate at midpoint of channel = 3.095(CFS) Natural valley channel type used L.A. County flood control district formula for channel velocity: Velocity(ft /s) _ (7 + 8(q(English Units) ".352)(slope"0.5) Velocity using mean channel flow = 3.69(Ft /s) Correction to map slope used on extremely rugged channels with drops and waterfalls (Plate D -6.2) Normal channel slope = 0.0380 Corrected /adjusted channel slope = 0.0380 Travel time = 2.26 min. TC = 34.65 min. Adding area flow.to channel UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.349 Decimal fraction soil group A = 1.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 0.000 RI index for soil(AMC 2) = 38.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 1.375(In /Hr) for a 10.0 year storm Subarea runoff = 0.609(CFS) for 1.270(Ac.) -D- 13 Total runoff = 3.380(CFS) Total area = 6.700(Ac.) End of computations, total study area = 23.20 (AC.) The following figures may be used for a unit hydrograph study of the same area. Area averaged pervious area fraction(Ap) = 0.846 Area averaged RI index number = 37.0 • • .IIN • • C7 Notes • "PROPOSED CONDITIONS" RATIONAL METHOD ANALYSIS 100 -YEAR STORM • a - I • Riverside County Rational Hydrology Program CIVILCADD /CIVILDESIGN Engineering Software,(c) 1989 - 2001 Version 6.4 Rational Hydrology Study Date: 08/29/04 File:1612p.out ------------------------------------------------------------------------ 1612 Centre Pointe 100 Year Storm Proposed Conditions ---------------------------------------------------------- ********* Hydrology Study Control Information * * * * * * * * ** English (in -lb) Units used in input data file ------------------------------------------------------------- Mainiero, Smith and Associates, Inc. - SIN 931 ------------------------------------------------------------- Rational Method Hydrology Program based on Riverside County Flood Control & Water Conservation District 1978 hydrology manual Storm event (year) = 100.00 Antecedent Moisture Condition = 3 Standard intensity- duration curves data (Plate D -4.1) For the [ Palm Springs ] area used. 10 year storm 10 minute intensity = 2.830(In /Hr) 10 year storm 60 minute intensity = 1.000(In /Hr) 100 year storm 10 minute intensity = 4.520(In /Hr) 100 year storm 60 minute intensity = 1.600(In /Hr) Storm event year = 100.0 Calculated rainfall intensity data: 1 hour intensity = 1.600(In /Hr) • Slope of intensity duration curve = 0.5800 +++++++++++++++++++++++++++++++++++++++ + + + + + + + ++ + + + + + + + + ++ +++ + + + ++ + + ++ Process from Point /Station 101.000 to Point /Station 102.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 610.000(Ft.) Top (of initial area) elevation = 117.800(Ft.) Bottom (of initial area) elevation = 101.100(Ft.) Difference in elevation = 16.700(Ft.) Slope = 0.02062 s(percent)= 2.06 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 9.499 min. Rainfall intensity = 4.660(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.897 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 8.315(CFS) Total initial stream area = 1.990(AC.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 102.000 to Point /Station 103.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** 0 Top of street segment elevation = 101.100(Ft.) End of street segment elevation = 85.100(Ft.) P_ - COMMERCIAL subarea type Runoff Coefficient = 0.897 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 7.760(CFS) Total initial stream area = 1.740(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + ++ + + + + + + + ++ Process from Point /Station 301.000 to Point /Station 302.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 370.000(Ft.) Top (of initial area) elevation = 116.800(Ft.) Bottom (of initial area) elevation = 111.000(Ft Difference in elevation = 5.800(Ft.) E -3 Length of street segment = 610.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) 43.000(Ft.) Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown .;v /hz) = 0.020 Street flow is on (1) side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 11.491(CFS) Depth of flow = 0.432(Ft.), Average velocity = 4.662(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 15.290(Ft.) Flow velocity = 4.66(Ft /s) Travel time = 2.18 min. TC = 11.68 min. Adding area flow to street COMMERCIAL subarea type Runoff Coefficient = 0.896 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 4.134(In /Hr) for a 100.0 year storm Subarea runoff = 5.631(CFS) for 1.520(Ac.) Total runoff = 13.946(CFS) Total area = 3.510(Ac.) Street flow at end of street = 13.946(CFS) Half street flow at end of street = 13.946(CFS) Depth of flow = 0.457(Ft.), Average velocity = 4.886(Ft/s) Flow width (from curb towards crown)= 16.515(Ft.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 201.000 to Point /Station 202.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 510.000(Ft.) Top (of initial area) elevation = 116.500(Ft.) Bottom (of initial area) elevation = 109.200(Ft.) Difference in elevation = 7.300(Ft.) Slope = 0.01431 s(percent)= 1.43 TC = k(0.300) *((length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 8.492 min. Rainfall intensity = 4.973(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.897 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 7.760(CFS) Total initial stream area = 1.740(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + ++ + + + + + + + ++ Process from Point /Station 301.000 to Point /Station 302.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 370.000(Ft.) Top (of initial area) elevation = 116.800(Ft.) Bottom (of initial area) elevation = 111.000(Ft Difference in elevation = 5.800(Ft.) E -3 17J • Slope = 0.01568 s(percent)= 1.57 TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 7.897 min. Rainfall intensity = 5.187(In /Hr) for a APARTMENT subarea type Runoff Coefficient = 0.894 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.200; Impervious Initial subarea runoff = 7.326(CFS) Total initial stream area = 1.580(Ac. Pervious area fraction = 0.200 100.0 year storm fraction = 0.800 +++++++++++++++++++++++++++++++++++++++ + + ++ + + + + + + + + + + + + ++ ++ + + ++ + + + + + ++ Process from Point /Station 401.000 to Point /Station 402.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 190.000(Ft.) Top (of initial area) elevation = 116.000(Ft.) Bottom (of initial area) elevation = 11.700(Ft.) Difference in elevation = 104.300(Ft.) Slope = 0.54895 s(percent)= 54.89 TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Warning: TC computed to be less than 5 min.; program time of concentration is 5 minutes. Initial area time of concentration = 5.000 min. Rainfall intensity = 6.762(In /Hr) for a 100.0 APARTMENT subarea type Runoff Coefficient = 0.895 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.200; Impervious fraction Initial subarea runoff = 5.145(CFS) Total initial stream area = 0.850(Ac.) Pervious area fraction = 0.200 is assuming the year storm = 0.800 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + ++ + + + + + + + + + + + + + + + + + ++ Process from Point /Station 501.000 to Point /Station 502.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 340.000(Ft.) Top (of initial area) elevation = 113.000(Ft.) Bottom (of initial area) elevation = 101.100(Ft.) Difference in elevation = 11.900(Ft.) Slope = 0.03500 s(percent)= 3.50 TC = k(0.300) *((length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 6.038 min. Rainfall intensity = 6.061(In /Hr) for a 100.0 COMMERCIAL subarea type Runoff Coefficient = 0.897 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious Initial subarea runoff = 6.037(CFS) Total initial stream area = 1.110(Ac Pervious area fraction = 0.100 year storm fraction = 0.900 +++++++++++++++++++++++++++++++++++++++ + + + + + + ++ + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 601.000 to Point /Station 602.000 W-H * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 460.000(Ft.) Top (of initial area) elevation = 113.000(Ft.) Bottom (of initial area) elevation = 105.100(Ft Difference in elevation = 7.900(Ft.) Slope = 0.01717 s(percent)= 1.72 TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 8.459 min. Rainfall intensity = 4.984(In /Hr) for a 100.0 year storm APARTMENT subarea type Runoff Coefficient = 0.894 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.200; Impervious fraction = 0.800 Initial subarea runoff = 6.191(CFS) Total initial stream area = 1.390(Ac.) Pervious area fraction = 0.200 +++++++++++++++++++++++++++++++++++++++ ++ + + + + + + + + ++ + + + + + + + + + ++ + ++++ + ++ Process from Point /Station 701.000 to Point /Station 702.000 * * ** INITIAL AREA EVALUATION * * ** Process from Point /Station 801.000 to Point /Station 802.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 660.000(Ft.) Top (of initial area) elevation = 116.000(Ft.) Bottom (of initial area) elevation = 101.500(Ft.) Difference in elevation = 14.500(Ft.) Slope = 0.02197 s(percent)= 2.20 TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 9.304 min. Rainfall intensity = 4.717(In /Hr) for a 100.0 year storm APARTMENT subarea type Runoff Coefficient = 0.893 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.200; Impervious fraction = 0.800 Initial subarea runoff = 15.632(CFS) Total initial stream area = 3.710(Ac.) Pervious area fraction = 0.200 Process from Point /Station 801.000 to Point /Station 802.000 * * ** INITIAL AREA EVALUATION * * ** E -S Initial area flow distance = 460.000(Ft.) Top (of initial area) elevation = 110.800(Ft.) Bottom (of initial area) elevation = 105.500(Ft.) Difference in elevation = 5.300(Ft.) Slope = 0.01152 s(percent)= 1.15 TC = k(0.370) *[(length ^3) /(elevation change)) ^0.2 Initial area time of concentration = 10.495 min. Rainfall intensity = 4.398(In /Hr) for a 100.0 year storm CONDOMINIUM subarea type Runoff Coefficient = 0.887 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.350; Impervious fraction = 0.650 Initial subarea runoff = 8.353(CFS) Total initial stream area = 2.140(Ac.) Pervious area fraction = 0.350 E -S Process from Point /Station 901.000 to Point /Station 902.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 117.800(Ft.) Bottom (of initial area) elevation = 113.000(Ft.) Difference in elevation = 4.800(Ft.) Slope = 0.00480 s(percent)= 0.48 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 13.832 min. Rainfall intensity = 3.747(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.896 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 5.375(CFS) Total initial stream area = 1.750(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + +++ + + + + + + + + ++ + ++ + + ++ + ++ Process from Point /Station 902.000 to Point /Station 903.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** E -� Top of street segment elevation = 113.000(Ft.) End of street segment elevation = 104.400(Ft.) Length of street segment = 775.000(Ft.) Height of curb above gutter flowline 6.0(In.) • _ Width of half street (curb to crown) 43.000(Ft.) Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on (1) side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 8.107(CFS) Depth of flow = 0.443(Ft.), Average velocity = 3.093(Ft /s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 15.794(Ft.) Flow velocity = 3.09(Ft /s) Travel time = 4.18 min. TC = 18.01 min. Adding area flow to street COMMERCIAL subarea type Runoff Coefficient = 0.895 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 3.216 {In /Hr) for a 100.0 year storm Subarea runoff = 3.829(CFS) for 1.330(Ac.) Total runoff = 9.704(CFS) Total area = 3.080(Ac.) Street flow at end of street = 9.704(CFS) Half street flow at end of street = 9.704(CFS) Depth of flow = 0.466(Ft.), Average velocity = 3.231(Ft /s) Flow width (from curb towards crown)= 16.961(Ft.) E -� +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 1001.000 to Point /Station 1002.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 560.000(Ft.) Top (of initial area) elevation = 109.000(Ft.) Bottom (of initial area) elevation = 104.900(Ft.) Difference in elevation = 4.100(Ft.) Slope = 0.00732 s(percent)= 0.73 TC = k(0.940) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 31.585 min. Rainfall intensity = 2.321(In /Hr) for a 100.0 year storm UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.852 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 91.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 7.908(CFS) Total initial stream area = 4.000(Ac.) Pervious area fraction = 1.000 +++++++++++++++++++++++++++++++++++++++ + + + + ++ + + + + + + + + + ++ + + + ++ + + + + + + + ++ Process from Point /Station 1002.000 to Point /Station 1003.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** Process from Point /Station 1101.000 to Point /Station 1102.000 C-7 Top of street segment elevation = 104.900(Ft.) End of street segment elevation = 97.900(Ft.) Length of street segment = 880.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 22.000(Ft.) • Distance from crown to crossfall grade break = 10.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) 0.020 Street flow is on [2] side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 12.010(CFS) Depth of flow = 0.426(Ft.), Average velocity = 2.535(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 14.973(Ft.) Flow velocity = 2.54(Ft /s) Travel time = 5.78 min. TC = 37.37 min. Adding area flow to street COMMERCIAL subarea type Runoff Coefficient = 0.893 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 2.106(in /Hr) for a 100.0 year storm Subarea runoff = 7.802(CFS) for 4.150(Ac.) Total runoff = 15.710(CFS) Total area = 8.150(Ac.) Street flow at end of street = 15.710(CFS) Half street flow at end of street = 7.855(CFS) Depth of flow = 0.460(Ft.), Average velocity = 2.706(Ft /s) Flow width (from curb towards crown)= 16.663(Ft.) Process from Point /Station 1101.000 to Point /Station 1102.000 C-7 • • 1x11 u * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 360.000(Ft.) Top (of initial area) elevation = 102.000(Ft.) Bottom (of initial area) elevation = 97.100(Ft.) Difference in elevation = 4.900(Ft.) Slope = 0.01361 s(percent)= 1.36 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 7.462 min. Rainfall intensity = 5.360(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.897 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 4.328(CFS) Total initial stream area = 0.900(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + ++ + + + + ++ Process from Point /Station 1201.000 to Point /Station 1202.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 380.000(Ft.) Top (of initial area) elevation = 102.500(Ft.) Bottom (of initial area) elevation = 100.400(Ft.) Difference in elevation = 2.100(Ft.) Slope = 0.00553 s(percent)= 0.55 TC = k(0.300) *[(length ^3) /(elevation change)) ^0.2 Initial area time of concentration = 9.132 min. Rainfall intensity = 4.768(In /Hr) for a 100.0 COMMERCIAL subarea type Runoff Coefficient = 0.897 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction Initial subarea runoff = 7.225(CFS) Total initial stream area = 1.690(Ac.) Pervious area fraction = 0.100 year storm 0.900 Process from Point /Station 1301.000 to Point /Station 1302.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 380.000(Ft.) Top (of initial area) elevation = 102.500(Ft.) Bottom (of initial area) elevation = 100.400(Ft.) Difference in elevation = 2.100(Ft.) Slope = 0.00553 s(percent)= 0.55 TC = k(0.300) *[(length ^3) /(elevation change)) ^0.2 Initial area time of concentration = 9.132 min. Rainfall intensity = 4.768(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.897 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 7.311(CFS) Total initial stream area = 1.710(Ac.) Pervious area fraction = 0.100 E-o Process from Point /Station 1401.000 to Point /Station 1402.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 985.000(Ft.) Top (of initial area) elevation = 104.000(Ft.) Bottom (of initial area) elevation = 96.900(Ft.) Difference in elevation = 7.100(Ft.) Slope = 0.00721 s(percent)= 0.72 TC = k(0.300) *[(length ^3) /(elevation change)) ^0.2 Initial area time of concentration = 12.675 min. Rainfall intensity = 3.942(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.896 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 10.739(CFS) Total initial stream area = 3.040(AC.) Pervious area fraction = 0.100 �� 1 +++++++++++++++++++++++++++++++++++++++ ++ + + + ++ + + + ++ + + + + + ++ + + + + + + + + + + ++ Process from Point /Station 1402.000 to Point /Station 1403.000 * * ** IMPROVED CHANNEL TRAVEL TIME * * ** Upstream point elevation = 96.900(Ft.) Downstream point elevation = 95.200(Ft.) Channel length thru subarea = 340.000(Ft.) Channel base width = 0.000(Ft.) Slope or 'Z' of left channel bank = 50.000 Slope or 'Z' of right channel bank = 50.000 Estimated mean flow rate at midpoint of channel = 14.483(CFS) Manning's 'N' = 0.015 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 14.483(CFS) Depth of flow = 0.360(Ft.), Average velocity = 2.233(Ft/s) Channel flow top width = 36.013(Ft.) Flow Velocity = 2.23(Ft /s) Travel time = 2.54 min. Time of concentration = 15.21 min. Sub - Channel No. 1 Critical depth = 0.350(Ft.) ' I Critical flow top width = 34.961(Ft.) ' I I Critical flow velocity= 2.370(Ft /s) ' Critical flow area = 6.111(Sq.Ft) Adding area flow to channel COMMERCIAL subarea type Runoff Coefficient = 0.896 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 3.546(In /Hr) for a 100.0 year storm Subarea runoff = 6.733(CFS) for 2.120(AC.) Total runoff =, 17.472(CFS) Total area = 5.160(AC.) Process from Point /Station 1501.000 to Point /Station 1502.000 • * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 475.000(Ft.) �� 1 • Top (of initial area) elevation = 105.700(Ft.) Bottom (of initial area) elevation = 98.500(Ft.) Difference in elevation = 7.200(Ft.) Slope = 0.01516 s(percent)= 1.52 TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 8.785 min. Rainfall intensity = 4.876(In /Hr) for a 100.0 APARTMENT subarea type Runoff Coefficient = 0.894 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.200; Impervious fraction Initial subarea runoff = 1.656(CFS) Total initial stream area = 0.380(AC.) Pervious area fraction = 0.200 year storm 0.800 +++++++++++++++++++++++++++++++++++++++ + ++++ + + + + + +++ + + + + + + + +++ + + + + + +++ Process from Point /Station 1502.000 to Point /Station 1503.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** Top of street segment elevation = 98.500(Ft.) End of street segment elevation = 93.70O(Ft.) Length of street segment = 580.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 10.000(Ft.) Distance from crown to crossfall grade break = 5.O00(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on [2] side(s) of the street Distance from curb to property line = 10.000(Ft.) • Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 0.160(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 9.171(CFS) Depth of flow = 0.245(Ft.), Average velocity = 2.712(Ft /s) Note: depth of flow exceeds top of street crown. Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 10.000(Ft.) Flow velocity = 2.71(Ft /s) Travel time = 3.56 min. TC = 12.35 min. Adding area flow to street APARTMENT subarea type Runoff Coefficient = 0.892 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.200; Impervious fraction = 0.800 Rainfall intensity = 4.002(In /Hr) for a 100.0 year storm Subarea runoff = 12.318(CFS) for 3.450(Ac.) Total runoff = 13.974(CFS) Total area = 3.830(Ac.) Street flow at end of street = 13.974(CFS) Half street flow at end of street = 6.987(CFS) Depth of flow = 0.294(Ft.), Average velocity = 3.203(Ft /s) Note: depth of flow exceeds top of street crown. Flow width (from curb towards crown)= 10.000(Ft.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 1601.000 to Point /Station 1602.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 950.000(Ft.) E -10 Top (of initial area) elevation = 106.100(Ft.) • Bottom (of initial area) elevation = 94.600(Ft.) Difference in elevation = 11.500(Ft.) Slope = 0.01211 s(percent)= 1.21 TC = k(0.390) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 14.641 min. Rainfall intensity = 3.626(In /Hr) for a 100.0 year storm SINGLE FAMILY (1/4 Acre Lot) Runoff Coefficient = 0.879 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 28.414(CFS) Total initial stream area = 8.920(Ac.) Pervious area fraction = 0.500 +++++++++++++++++++++++++++++++++++++++ + + + + + + ++ + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station :801.000 to Point /Station 1802.000 * * ** INITIAL AREA EVALUATION * *'* Initial area flow distance = 200.000(Ft.) Top (of initial area) elevation = 113.000(Ft.) Bottom (of initial area) elevation = 105.400(Ft.) Difference in elevation = 7.600(Ft.) Slope = 0.03800 s(percent)= 3.80 TC = k(0.300) *((length ^3) /(elevation change)] ^0.2 Warning: TC computed to be less than 5 min.; program is assuming the time of concentration is 5 minutes. Initial area time of concentration = 5.000 min. Rainfall intensity = 6.762(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.898 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + ++ ++ + + + + + ++ fraction soil Process from Point /Station 1701.000 to Point /Station 1702.000 * * ** INITIAL AREA EVALUATION * * ** fraction soil Initial area flow distance = 420.000(Ft.) Top (of initial area) elevation = 109.000(Ft.) fraction soil Bottom (of initial area) elevation = 100.500(Ft.) Difference in elevation = 8.500(Ft.) fraction soil Slope = 0.02024 s(percent)= 2.02 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 for soil(AMC Initial area time of concentration = 7.331 min. Rainfall intensity = 5.416(In /Hr) for a 100.0 year storm area fraction COMMERCIAL subarea type Runoff Coefficient = 0.897 • Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 • Decimal fraction soil group C = 0.000 stream area area fraction Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 3.304(CFS) Total initial stream area = 0.680(AC.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + ++ + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station :801.000 to Point /Station 1802.000 * * ** INITIAL AREA EVALUATION * *'* Initial area flow distance = 200.000(Ft.) Top (of initial area) elevation = 113.000(Ft.) Bottom (of initial area) elevation = 105.400(Ft.) Difference in elevation = 7.600(Ft.) Slope = 0.03800 s(percent)= 3.80 TC = k(0.300) *((length ^3) /(elevation change)] ^0.2 Warning: TC computed to be less than 5 min.; program is assuming the time of concentration is 5 minutes. Initial area time of concentration = 5.000 min. Rainfall intensity = 6.762(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.898 E -I C Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 1.214(CFS) • Total initial Pervious stream area area fraction = 0.200(Ac.) = 0.100 E -I C Process from Point /Station 1901.000 to Point /Station 1902.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 370.000(Ft.) Top (of initial area) elevation = 111.500(Ft.) Bottom (of initial area) elevation = 101.500(Ft.) Difference in elevation = 10.000(Ft.) Slope = 0.02703 s(percent)= 2.70 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 6.577 min. Rainfall intensity = 5.767(In /Hr) for a 100.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.897 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 4.399(CFS) Total initial stream area = 0.850(AC.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ ++ + ++ + + + + + + + +++ + + + ++ + + + + + + + + + ++ Process from Point /Station 2001.000 to Point /Station 2002.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 390.000(Ft.) Top (of initial area) elevation = 96.000(Ft.) Bottom (of initial area) elevation = 92.300(Ft.) Difference in elevation = 3.700(Ft.) • Slope = 0.00949 s(percent)= 0.95 TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 8.917 min. Rainfall intensity = 4.834(In /Hr) for a 100.0 year storm APARTMENT subarea type Runoff Coefficient = 0.893 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 3) = 88.00 Pervious area fraction = 0.200; Impervious fraction = 0.800 Initial subarea runoff = 3.887(CFS) Total initial stream area = 0.900(Ac.) Pervious area fraction = 0.200 End of computations, total study area = 52.10 (AC.) The following figures may be used for a unit hydrograph study of the same area. Area averaged pervious area fraction(Ap) = 0.271 Area averaged RI index number = 75.4 r� J E -12 • "PROPOSED CONDITIONS" RATIONAL METHOD ANALYSIS 10 -YEAR STORM E -13 • Riverside County Rational Hydrology Program CIVILCADD /CIVILDESIGN Engineering Software,(c) 1989 - 2001 Version 6.4 Rational Hydrology Study Date: 08/29/04 File:1612p.out ---------------------------------------------------------------------- 1612 Centre Pointe 10 Year Storm Proposed Conditions ----------------------------------------------------------------------- ********* Hydrology Study Control Information * * * * * * * * ** English (in -lb) Units used in input data file ------------------------------------------------------------------------ Mainiero, Smith and Associates, Inc. - S/N 931 ------------------------------------------------------------------------ Rational Method Hydrology Program based on Riverside County Flood Control & Water Conservation District 1978 hydrology manual Storm event (year) = 10.00 Antecedent Moisture Condition = 2 Standard intensity- duration curves data (Plate D -4.1) For the [ Palm Springs ] area used. 10 year storm 10 minute intensity = 2.830(In /Hr) 10 year storm 60 minute intensity = 1.000(In /Hr) 100 year storm 10 minute intensity = 4.520(In /Hr) 100 year storm 60 minute intensity = 1.600(In /Hr) Storm event year = 10.0 Calculated rainfall intensity data: 1 hour intensity = 1.000(In /Hr) • Slope of intensity duration curve = 0.5800 +++++++++++++++++++++++++++++++++++++++ + + + + ++ + + + + + ++ ++ + + + + + + +++ + + + ++++ Process from Point /Station 101.000 to Point /Station 102.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 810.000(Ft.) Top (of initial area) elevation = 117.800(Ft.) Bottom (of initial area) elevation = 101.100(Ft.) Difference in elevation = 16.700(Ft.) Slope = 0.02062 s(percent)= 2.06 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 9.499 min. Rainfall intensity = 2.913(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.888 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 5.147(CFS) Total initial stream area = 1.990(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + ++ + + + + + + + + + + + + + + + + + ++ Process from Point /Station 102.000 to Point /Station 103.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** • Top of street segment elevation = 101.100(Ft.) End of street segment elevation = 85.100(Ft.) E —It Length of street segment = 610.000(Ft.). • Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) 43.000(Ft.) Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on [1] side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 7.113(CFS) Depth of flow = 0.378(Ft.), Average velocity = 4.157(Ft /s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 12.588(Ft.) Flow velocity = 4.16(Ft /s) Travel time = 2.45 min. TC = 11.94 min. Adding area flow to street COMMERCIAL subarea type Runoff Coefficient = 0.887 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = G.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 2.550(In /Hr) for a 10.0 year storm Subarea runoff = 3.437(CFS) for 1.520(Ac.) Total runoff = 8.584(CFS) Total area = 3.510(Ac.) Street flow at end of street = 8.584(CFS) Half street flow at end of street = 8.584(CFS) • Depth of flow = 0.399(Ft.), Average velocity = 4.347(Ft/s) Flow width (from curb towards crown)= 13.594(Ft.) +++++++++++++++++++++++++++++++++++++++ + + + ++ + + + + + ++ ++ + + + + + ++ ++ + + + + + + ++ Process from Point /Station 201.000 to Point /Station 202.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 510.000(Ft.) Top (of initial area) elevation = 116.500(Ft.) Bottom (of initial area) elevation = 109.200(Ft.) Difference.in elevation = 7.300(Ft.) Slope = 0.01431 s(percent)= 1.43 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 8.492 min. Rainfall intensity = 3.108(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.889 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 4.807(CFS) Total initial stream area = 1.740(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + ++ + + + + + + + + + ++ Process from Point /Station 301.000 to Point /Station 302.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 370.000(Ft.) • Top (of initial area) elevation = 116.800(Ft.) Bottom (of initial area) elevation = 111.000(Ft.) Difference in elevation = 5.800(Ft.) E-►15 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + ++ + + + + + + + + + ++ + + + ++ Process from Point /Station 501.000 to Point /Station 502.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 340.000(Ft.) Top (of initial area) elevation = 113.000(Ft.) Bottom (of initial area) elevation = 101.100(Ft.) Difference in elevation = 11.900(Ft.) Slope = 0.03500 s(percent)= 3.50 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 6.038 min. Rainfall intensity = 3.788(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.891 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 3.744(CFS) Total initial stream area = 1.110(Ac.) Pervious area fraction = 0.100 0 Process from Point /Station 601.000 to Point /Station 602.000 Slope = 0.01568 s(percent)= 1.57 TC = k(0.323) *((length ^3) /(elevation change)) ^0.2 Initial area time of concentration = 7.897 min. Rainfall intensity = 3.242(In /Hr) for a 10.0 year storm APARTMENT subarea type Runoff Coefficient = 0.878 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.200; Impervious fraction = 0.800 Initial subarea runoff = 4.499(CFS) Total initial stream area = 1.580(AC.) Pervious area fraction = 0.200 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + ++ + + + + ++ + + + + + + + + + + ++ + ++ Process from Point /Station 401.000 to Point /Station 402.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 190.000(Ft.) Top (of initial area) elevation = 116.000(Ft.) Bottom (of initial area) elevation = 11.700(Ft.) Difference in elevation = 104.300(Ft.) Slope = 0.54895 s(percent)= 54.89 TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Warning: TC computed to be less than 5 min.; program is assuming the time of concentration is 5 minutes. Initial area time of concentration = 5.000 min. Rainfall intensity = 4.226(In /Hr) for a 10.0 year storm APARTMENT subarea type Runoff Coefficient = 0.883 Decimal fraction soil group A = 0.000 • Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.200; Impervious fraction = 0.800 Initial subarea runoff = 3.171(CFS) Total initial stream area = 0.850(Ac.) Pervious area fraction = 0.200 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + ++ + + + + + + + + + ++ + + + ++ Process from Point /Station 501.000 to Point /Station 502.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 340.000(Ft.) Top (of initial area) elevation = 113.000(Ft.) Bottom (of initial area) elevation = 101.100(Ft.) Difference in elevation = 11.900(Ft.) Slope = 0.03500 s(percent)= 3.50 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 6.038 min. Rainfall intensity = 3.788(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.891 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 3.744(CFS) Total initial stream area = 1.110(Ac.) Pervious area fraction = 0.100 0 Process from Point /Station 601.000 to Point /Station 602.000 ++++++ t++++++++t++++++ 4+ t+++++ t++++++++ + +t ++t + + + + + +k + + +tt++ + + + + + + + + +++ Process from Point /Station 701.000 to Point /Station 702.000 * * ** INITIAL AREA EVALUATION * * ** * * ** INITIAL AREA EVALUATION * * ** • Top (of initial area) elevation = 116.000(Ft.) Initial area flow distance = 460.000(Ft.) Bottom (of initial area) elevation = 101.500(Ft.) Top (of initial area) elevation = 113.000(Ft.) Difference in elevation = 14.500(Ft.) Bottom (of initial area) elevation = 105.100(Ft.) Slope = 0.02197 s(percent)= 2.20 Difference in elevation = 7.900(Ft.) TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Slope = 0.01717 s(percent)= 1.72 Initial area time of concentration = 9.304 min. TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Rainfall intensity = 2.948(In /Hr) for a 10.0 year storm APARTMENT subarea type Initial area time of concentration = 8.459 min. Runoff Coefficient = 0.876 Rainfall intensity = 3.115(In /Hr) for a 10.0 year storm Decimal fraction soil group A = 0.000 APARTMENT subarea type Decimal fraction soil group B = 0.000 Runoff Coefficient = 0.878 Decimal fraction soil group C = 0.000 Decimal fraction soil group A = 0.000 Decimal fraction soil group D = 1.000 Decimal fraction soil group B = 0.000 RI index for soil(AMC 2) = 75.00 Decimal fraction soil group C = 0.000 Pervious area fraction = 0.200; Impervious fraction = 0.800 Decimal fraction soil group D = 1.000 Initial subarea runoff = 9.585(CFS) RI index for soil(AMC 2) = 75.00 Total initial stream area = 3.710(Ac.) Pervious area fraction = 0.200; Impervious fraction = 0.800 Pervious area fraction = 0.200 Initial subarea runoff = 3.800(CFS) Total initial stream area = 1.390(Ac.) Pervious area fraction = 0.200 ++++++ t++++++++t++++++ 4+ t+++++ t++++++++ + +t ++t + + + + + +k + + +tt++ + + + + + + + + +++ Process from Point /Station 701.000 to Point /Station 702.000 * * ** INITIAL AREA EVALUATION * * ** +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 801.000 to Point /Station 802.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 660.000(Ft.) Top (of initial area) elevation = 116.000(Ft.) Bottom (of initial area) elevation = 101.500(Ft.) Difference in elevation = 14.500(Ft.) Slope = 0.02197 s(percent)= 2.20 TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 9.304 min. • Rainfall intensity = 2.948(In /Hr) for a 10.0 year storm APARTMENT subarea type Runoff Coefficient = 0.876 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.200; Impervious fraction = 0.800 Initial subarea runoff = 9.585(CFS) • Total initial stream area = 3.710(Ac.) Pervious area fraction = 0.200 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++ Process from Point /Station 801.000 to Point /Station 802.000 * * ** INITIAL AREA EVALUATION * * ** —' l Initial area flow distance = 460.000(Ft.) Top (of initial area) elevation = 110.800(Ft.) Bottom (of initial area) elevation = 105.500(Ft.) Difference in elevation = 5.300(Ft.) Slope = 0.01152 s(percent)= 1.15 TC = k(0.370) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 10.495 min. Rainfall intensity = 2.749(In /Hr) for a 10.0 year storm CONDOMINIUM subarea type Runoff Coefficient = 0.856 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.350; Impervious fraction = 0.650 • Initial subarea runoff = 5.036(CFS) Total initial stream area = 2.140(Ac.) Pervious area fraction = 0.350 —' l Process from Point /Station 901.000 to Point /Station 902.000 * * ** INITIAL AREA EVALUATION * * ** . Initial area flow distance = 1000.000(Ft.) Top (of initial area) elevation = 117.800(Ft.) Bottom (of initial area) elevation = 113.000(Ft.) Difference in elevation = 4.600(Ft.) Slope = 0.00480 s(percent)= 0.48 TC = k(0.300) *((length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 13.832 min. Rainfall intensity = 2.342(In /Hr) for a 10.0 COMMERCIAL subarea type Runoff Coefficient = 0.886 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction Initial subarea runoff = 3.630(CFS) Total initial stream area = 1.750(Ac.) Pervious area fraction = 0.100 year storm 0.900 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + ++ + + + + + + + + + + + + + ++ Process from Point /Station 902.000 to Point /Station 903.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** Top of street segment elevation = 113.000(Ft.) End of street segment elevation = 104.400(Ft.) Length of street segment = 775.000(Ft.) Height of curb above gutter flowline = 6.0(In.) • Width of half street (curb to crown) 43.000(Ft.) Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on (1] side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 5.010(CFS) Depth of flow = 0.387(Ft.), Average velocity = 2.755(Ft/s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 13.006(Ft.) Flow velocity = 2.76(Ft /s) Travel time = 4.69 min. TC = 18.52 min. Adding area flow to street COMMERCIAL subarea type Runoff Coefficient = 0.883 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 1.977(In /Hr) for a 10.0 year storm Subarea runoff = 2.324(CFS) for 1.330(Ac.) Total runoff = 5.954(CFS) Total area = 3.080(AC.) Street flow at end of street = 5.954(CFS) Half street flow at end of streez = 5.954(CFS) Depth of flow = 0.406(Ft.), Average velocity = 2.871(Ft /s) • Flow width (from curb towards crown)= 13.953(Ft.) • Process from Point /Station 1001.000 to Point /Station 1002.000 * * ** INITIAL AREA EVALUATION * * *x Initial area flow distance = 560.000(Ft.) Top (of initial area) elevation = 109.000(Ft.) Bottom (of initial area) elevation = 104.900(Ft.) Difference in elevation = 4.100(Ft.) Slope = 0.00732 s(percent)= 0.73 TC = k(0.940) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 31.585 min. Rainfall intensity = 1.451(in /Hr) for a 10.0 year storm UNDEVELOPED (good cover) subarea Runoff Coefficient = 0.732 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 80.00 Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 4.247(CFS) Total initial stream area = 4.000(Ac.) Pervious area fraction = 1.000 e -19 +++++++++++++++++++++++++++++++++++++++ + +++ + + +++ + + + + + + + + +++ + + ++ ++ + + + ++ Process from Point /Station 1002.000 to Point /Station 1003.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** Top of street segment elevation = 104.900(Ft.) End of street segment elevation = 97.900(Ft.) Length of street segment = 880.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 22.000(Ft.) • Distance from crown to crossfall grade break = 10.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on [2] side(s) of the street Distance from curb to property line = 12.000(Ft.) Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 2.000(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 6.451(CFS) Depth of flow = 0.359(Ft.), Average velocity = 2.187(Ft /s) Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 11.611(Ft.) Flow velocity = 2.7.9(Ft /s) Travel time = 6.71 min. TC = 38.29 min. Adding area flow to street COMMERCIAL subarea type Runoff Coefficient = 0.877 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 1.298(In /Hr) for a 10.0 year storm Subarea runoff = 4.723(CFS) for 4.150(Ac.) Total runoff = 8.970(CFS) Total area = 8.150(Ac.) Street flow at end of street = 8.970(CFS) Half street flow at end of stree= = 4.485(CFS) Depth of flow = 0.393(Ft.), Average velocity = 2.364(Ft/s) Flow width (from curb towards crown)= 13.306(Ft.) Process from Point /Station 1101.000 to Point /Station 1102.000 e -19 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + ++ + ++ + ++ + + + + ++ + + + + ++ Process from Point /Station 1201.000 to Point /Station 1202.000 * * ** INITIAL AREA EVALUATION * * ** * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 360.000(Ft.) Top (of initial area) elevation = 102.000(Ft.) Bottom (of initial area) elevation.= 97.100(Ft.) Difference in elevation = 4.900(Ft.) Slope = 0.01361 s(percent)= 1.36 TC = k(0.300) *((length ^3) /(elevation change)] ^0.2 • Initial area time of concentration = 7.462 min. Rainfall intensity = 3.350(n /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.889 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 2.682(CFS) Total initial stream area = 0.900(AC.) • Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + ++ + ++ + ++ + + + + ++ + + + + ++ Process from Point /Station 1201.000 to Point /Station 1202.000 * * ** INITIAL AREA EVALUATION * * ** EE -W Initial area flow distance = 360.000(Ft.) Top (of initial area) elevation = 102.500(Ft.) Bottom (of initial area) elevation = 100.400(Ft.) Difference in elevation = 2.100(Ft.) Slope = 0.00553 s(percent)= 0.55 TC = k(0.300) *[(length ^3) /(eleva,--ion change)] ^0.2 Initial area time of concentration = 9.132 min. • Rainfall intensity = 2.980(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.888 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 4.474(CFS) Total initial stream area = 1.690(Ac.) Pervious area fraction = 0.100 EE -W +++++++++++++++++++++++++++++++++++++++ + ++ + + + + + + + + + + ++ + + + + + + + + + + ++ + + ++ Process from Point /Station 1301.000 to Point /Station 1302.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 380.000(Ft.) Top (of initial area) elevation = 102.500(Ft.) Bottom (of initial area) elevation = 100.400(Ft.) Difference in elevation = 2.100(Ft.) Slope = 0.00553 s(percent)= 0.55 TC = k(0.300) *[(length ^3) /(elevation change)) ^0.2 Initial area time of concentration = 9.132 min. Rainfall intensity = 2.980(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.888 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 3.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 • Initial subarea runoff = 4.527(CFS) Total initial stream area = 1.710(AC.) Pervious area fraction = 0.100 EE -W Process from Point /Station 1401.000 to Point /Station 1402.000 . * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 985.000(Ft.) Top (of initial area) elevation = 104.000(Ft.) Bottom (of initial area) elevation = 96.900(Ft.) Difference in elevation = 7.100(Ft.) Slope = 0.00721 s(percent)= 0.72 TC = k(0.300) *((length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 12.675 min. Rainfall intensity = 2.464(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.886 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 6.638(CFS) Total initial stream area = 3.040(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + ++ + + + + ++ ++ Process from Point /Station 1402.000 to Point /Station 1403.000 * * ** IMPROVED CHANNEL TRAVEL TIME * * ** • Adding area flow to channel COMMERCIAL subarea type Runoff Coefficient = 0.885 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = C.000 Decimal fraction soil group C = C.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 2.190(In /Hr) for a 10.0 year storm Subarea runoff = 4.107(CFS) for 2.120(Ac.) Total runoff = 10.745(CFS) Total area = 5.160(Ac.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + ++ + + + + + ++ Process from Point /Station 1501.000 to Point /Station 1502.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 475.000(Ft.) C-Z� Upstream point elevation = 96.900(Ft.) Downstream point elevation = 95.200(Ft.) Channel length thru subarea = 340.000(Ft.) Channel base width = 0.000(Ft.) • Slope or 'Z' of left channel bank = 50.000 Slope or 'Z' of right channel bank = 50.000 Estimated mean flow rate at midpoint of channel = 8.953(CFS) Manning's 'N' = 0.015 Maximum depth of channel = 1.000(Ft.) Flow(q) thru subarea = 8.953(CFS) Depth of flow = 0.301(Ft.), Average velocity = 1.980(Ft /s) Channel flow top width = 30.069(Ft.) Flow Velocity = 1.98(Ft /5) Travel time = 2.86 min. Time of concentration = 15.54 min. Sub - Channel No. 1 Critical depth = 0.289(Ft.) ' I I Critical flow top width = 28.906(Ft.) ' I I Critical flow velocity= 2.143(Ft /s) ' I I Critical flow area = 4.178(Sq.Ft) • Adding area flow to channel COMMERCIAL subarea type Runoff Coefficient = 0.885 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = C.000 Decimal fraction soil group C = C.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Rainfall intensity = 2.190(In /Hr) for a 10.0 year storm Subarea runoff = 4.107(CFS) for 2.120(Ac.) Total runoff = 10.745(CFS) Total area = 5.160(Ac.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + ++ + + + + + ++ Process from Point /Station 1501.000 to Point /Station 1502.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 475.000(Ft.) C-Z� • Top (of initial area) elevation = 105.700(Ft.) Bottom (of initial area) elevation = 98.500(Ft.) Difference in elevation = 7.200(Ft.) Slope = 0.01516 s(percent)= 1.52 TC = k(0.323) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 8.785 min. Rainfall intensity = 3.048(In /Hr) for a 10.0 APARTMENT subarea type Runoff Coefficient = 0.877 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.200; Impervious Initial subarea runoff = 1.016(CFS) Total initial stream area = 0.380(Ac Pervious area fraction = 0.200 year storm fraction = 0.800 +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + ++ ++ + + + + + + + + + + + + + + + +++ Process from Point /Station 1502.000 to Point /Station 1503.000 * * ** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION * * ** Top of street segment elevation = 98.500(Ft.) End of street segment elevation = 93.700(Ft.) Length of street segment = 580.000(Ft.) Height of curb above gutter flowline = 6.0(In.) Width of half street (curb to crown) = 10.000(Ft.) Distance from crown to crossfall grade break = 5.000(Ft.) Slope from gutter to grade break (v /hz) = 0.020 Slope from grade break to crown (v /hz) = 0.020 Street flow is on [2] side(s) of the street Distance from curb to property line = 10.000(Ft.) • Slope from curb to property line (v /hz) = 0.020 Gutter width = 2.000(Ft.) Gutter hike from flowline = 0.160(In.) Manning's N in gutter = 0.0150 Manning's N from gutter to grade break = 0.0150 Manning's N from grade break to crown = 0.0150 Estimated mean flow rate at midpoint of street = 5.627(CFS) Depth of flow = 0.202(Ft.), Average velocity = 2.234(Ft/s) Note: depth of flow exceeds top of street crown. Streetflow hydraulics at midpoint of street travel: Halfstreet flow width = 10.000(Ft.) Flow velocity = 2.23(Ft /s) Travel time = 4.33 min. TC = 13.11 min. Adding area flow to street APARTMENT subarea type Runoff Coefficient = 0.872 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.200; Impervious fraction = 0.800 Rainfall intensity = 2.416(In /Hr) for a 10.0 year storm Subarea runoff = 7.268(CFS) for 3.450(Ac.) Total runoff = 8.284(CFS) Total area = 3.830(Ac.) Street flow at end of street = 8.284(CFS) Half street flow at end of stree� = 4.142(CFS) Depth of flow = 0.235(Ft.), Average velocity = 2.604(Ft /s) Note: depth of flow exceeds top of street crown. Flow width (from curb towards crown)= 10.000(Ft.) +++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + ++ + + + ++ Process from Point /Station 1601.000 to Point /Station 1602.000 • * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 950.000(Ft.) F- 22 • Top (of initial area) elevation = 106.100(Ft.) Bottom (of initial area) elevation = 94.600(Ft.) Difference in elevation = 11.500(Ft.) Slope = 0.01211 s(percent)= 1.21 TC = k(0.390) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 14.641 min. Rainfall intensity = 2.266(In /Hr) for a 10.0 year storm SINGLE FAMILY (1/4 Acre Lot) Runoff Coefficient = 0.826 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 16.702(CFS) Total initial stream area = 8.920(Ac.) Pervious area fraction = 0.500 Process from Point /Station 1701.000 to Point /Station 1702.000 * * ** INITIAL AREA EVALUATION * * ** Process from Point /Station 1801.000 to Point /Station 1802.000 * * ** INITIAL AREA EVALUATION.***- Initial area flow distance = 200.000(Ft.) Top (of initial area) elevation = 113.000(Ft.) Bottom (of initial area) elevation— 105.400(Ft.) Difference in elevation = 7.600(Ft.) Slope = 0.03800 s(percent)= 3.80 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Warning: TC computed to be less than 5 min.; program is assuming the time of concentration is 5 minutes. Initial area time of concentration = 5.000 min. Rainfall intensity = 4.226(In/Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.891 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 0.753(CFS) • Total initial stream area = 0.200(Ac.) Pervious area fraction = 0.100 E -23 Initial area flow distance = 420.000(Ft.) Top (of initial area) elevation = 109.000(Ft.) Bottom (of initial area) elevation = 100.500(Ft.) Difference in elevation = 8.500(Ft.) Slope = 0.02024 s(percent)= 2.02 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 7.331 min. Rainfall intensity = 3.385( =n /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.890 • Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 2.047(CFS) Total initial stream area = 0.680(Ac.) Pervious area fraction = 0.100 Process from Point /Station 1801.000 to Point /Station 1802.000 * * ** INITIAL AREA EVALUATION.***- Initial area flow distance = 200.000(Ft.) Top (of initial area) elevation = 113.000(Ft.) Bottom (of initial area) elevation— 105.400(Ft.) Difference in elevation = 7.600(Ft.) Slope = 0.03800 s(percent)= 3.80 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Warning: TC computed to be less than 5 min.; program is assuming the time of concentration is 5 minutes. Initial area time of concentration = 5.000 min. Rainfall intensity = 4.226(In/Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.891 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 0.753(CFS) • Total initial stream area = 0.200(Ac.) Pervious area fraction = 0.100 E -23 Process from Point /Station 1901.000 to Point /Station 1902.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 370.000(Ft.) Top (of initial area) elevation = 111.500(Ft.) Bottom (of initial area) elevation = 101.500(Ft.) Difference in elevation = 10.000(Ft.) Slope = 0.02703 s(percent)= 2.70 TC = k(0.300) *[(length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 6.577 min. Rainfall intensity = 3.605(In /Hr) for a 10.0 year storm COMMERCIAL subarea type Runoff Coefficient = 0.890 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.100; Impervious fraction = 0.900 Initial subarea runoff = 2.727(CFS) Total initial stream area = 0.850(Ac.) Pervious area fraction = 0.100 +++++++++++++++++++++++++++++++++++++++ + + + + + ++ + + + + + ++ ++ + + + + + +++ + + + + + ++ Process from Point /Station 2001.000 to Point /Station 2002.000 * * ** INITIAL AREA EVALUATION * * ** Initial area flow distance = 390.000(Ft.) Top (of initial area) elevation = 96.000(Ft.) Bottom (of initial area) elevation = 92.300(Ft.) Difference in elevation = 3.700(Ft.) • Slope = 0.00949 s(percent)= 0.95 TC = k(0.323) *((length ^3) /(elevation change)] ^0.2 Initial area time of concentration = 8.917 min.. Rainfall intensity = 3.021(In /Hr) for a 10.0 year storm APARTMENT subarea type Runoff Coefficient = 0.877 Decimal fraction soil group A = 0.000 Decimal fraction soil group B = 0.000 Decimal fraction soil group C = 0.000 Decimal fraction soil group D = 1.000 RI index for soil(AMC 2) = 75.00 Pervious area fraction = 0.200; Impervious fraction = 0.800 Initial subarea runoff = 2.385(CFS) Total initial stream area = 0.900(Ac.) Pervious area fraction = 0.200 End of computations, total study area = 52.10 (AC.) The following figures may be used for a unit hydrograph study of the same area. Area averaged pervious area fraction(Ap) = 0.271 Area averaged RI index number = 75.4 • '[5-2k Notes S l • • CVWD LETTER, DATED 2/20/04 and Correspondence 0 � -1 • Planning Commission City of La Quinta Post Office Box 1504 La Quinta, California 92253 Gentlemen: Subject: Tentative Parcel MagNo. 31116 This area is protected from regional stormwater flows by the Coachella Valley Stormwater Channel and may be considered safe from regional stormwater flows except in rare instances. This area is designated Zone X on Federal Flood Insurance rate maps which are in effect at this time by the Federal Emergency Management Agency. There may be erosion of the banks of the Coachella Valley Stormwater Channel during periods of unusual rainfall and discharge. The developer shall construct concrete slope protection on the bank of the stormwater channel to prevent erosion. Plans for concrete slope protection shall be submitted to the District for review. These plans shall ensure a 20 -foot access road is maintained along the slope protection. Stormwater runoff from this area may be diverted to the Coachella Valley Stormwater Channel. Nuisance flows or other nonstormwater generated runoff may not be discharged into the Coachella Valley Stormwater Channel. Plans for stormwater slope protection shall be submitted to the District for review. TRUE CONSERVATION USE WATER WISELY r -Z .Y' ESTABLISHED IN 1918 AS A PUBLIC ACy.,.a'Y a ;.. COACHELLA VALLEY WATER DISTRICT POST OFFICE BOX 1058 • COACHELLA, CALIFORNIA 92236 • TELEPHONE (760) 398 -2651 • FAX (760) 398 -3711 DIRECTORS: OFFICERS: JOHN W. WADDEN, PRESIDENT STEVEN B. ROBBINS, PETER NELSON, VICE PRESIDENT GENERAL MANAGER -CHIEF ENGINEER TELLIS COOEKAS MARK BEUHLER. RUSSELL KITAHARA ASST GENERAL MANAGER PATRICIA A. LARSON February 20, 2004 JAN PAERNANASST TO GENERAL MANAGER REDWINE AND SHERRILL, ATTORNEYS File: 0163.1 0- 0421.1 0721.1 L • Planning Commission City of La Quinta Post Office Box 1504 La Quinta, California 92253 Gentlemen: Subject: Tentative Parcel MagNo. 31116 This area is protected from regional stormwater flows by the Coachella Valley Stormwater Channel and may be considered safe from regional stormwater flows except in rare instances. This area is designated Zone X on Federal Flood Insurance rate maps which are in effect at this time by the Federal Emergency Management Agency. There may be erosion of the banks of the Coachella Valley Stormwater Channel during periods of unusual rainfall and discharge. The developer shall construct concrete slope protection on the bank of the stormwater channel to prevent erosion. Plans for concrete slope protection shall be submitted to the District for review. These plans shall ensure a 20 -foot access road is maintained along the slope protection. Stormwater runoff from this area may be diverted to the Coachella Valley Stormwater Channel. Nuisance flows or other nonstormwater generated runoff may not be discharged into the Coachella Valley Stormwater Channel. Plans for stormwater slope protection shall be submitted to the District for review. TRUE CONSERVATION USE WATER WISELY r -Z Planning Commission • City of La Quinta -2- February 20, 2004 The District will furnish domestic water and sanitation service to this area in accordance with . the current regulations of this District. These regulations provide for the payment of certain fees and charges by the subdivider and said fees and charges are subject to change. This area shall be annexed to Improvement District Nos. 55 and 82 of the District for sanitation service. Plans for grading, landscaping and irrigation systems shall be submitted to the District for review. This review is for ensuring efficient water management. If you have any questions please call Dan Charlton, Stormwater Engineer, extension 2316. Yours very truly, �i • cc: Jeff Johnson Riverside County Department of Public Health 82 -675 Highway 111, CAC Building, Second Floor, Room 209 Indio, California 92201 DC: tAenglsw\feb\ttrn31116 050719 -3 050719-4 • COACHELLA VALLEY WATER DISTRICT V-- -3 De La Torre, Julian From: Dan Charlton [dcharlton @cvwd.org] ent: Thursday, September 09, 2004 9:35 AM To: De LaTorre, Julian Subject: City of La Quinta Centre Point Project Julian: The following is a summary of CVWD requirments for the above - mentioned project: 1. Prior to occupancy of any structure within the development, concrete slope protection shall be constructed. 2. Prior to the construciton of slope protection, a detailed hydraulic analysis shall be submitted to CVWD for review. The review will be completed by our consultant and will require a deposit of $10,000 to begin the review. 3. The Storm drain inlet can be installed prior to the installation of slope protection. However, proper erosion protection and a head wall will be required. When slope protection is constructed, the storm drain inlet can be cut and incorporated into the slope. A permanent encroachment permit is required for 0 &M and a construction encroachment permit is required for construction of the inlet within our R.O.W. 4. It is my understanding that the slope above the CVWD access road is within CVWD right -of -way. If this is the case, a slope of 2:1 will be required. 5. The concrete slope protection shall be tied -in to the slope protection under the bridge, the drop structure, and the D/S slope protection at Century Sienna. Doweling •shall be at 18 -inch o.c. Also, a construction encroachment permit is required for the installation of the slope protection. If you have any other questions, please give me a call at extension 2316. Dan Charlton- 0 1 F.-4 De LaTorre, Julian From: Dan Charlton [dcharlton @cvwd.org] OT ent: Friday, September 10, 2004 1:45 PM o: De LaTorre, Julian Subject: Centre Pointe at La Quinta • • Julian: Although discussed in the meeting, I thought I should reiterate that nuisance water will not be accepted in.the Coachella Valley Stormwater Channel. Therefore, all storm drain inlets to the channel shall include a drywell. Thanks, Dan Charlton F -5 Notes • � .0 EXISTING HYDROLOGY MAP G-1 salom • PROPOSED HYDROLOGY MAP • H-( • • �i ����� 0 ROUGH GRADING PLAN .T- - I November 26, 2008 Brian Ching, Associate Engineer Public Works /Development Services Division CITY OF LA QUINTA PO Box 1504 La Quinta CA 92247 -1504 Re: On -Site Hydrology for TTM 36089 and Review of Parcel Map 31116 Precise Grading Plans for Pool, Office Buildings, and Building Nos. 1 -14 Dear Brian: With regard to the on -site hydrology requirements for TTM 36089, 1 have reviewed the Precise Grading Plans for Parcel Map 31116 - Pool, Office Buildings, and Building Nos. 1 -14. The ridgelines between Buildings 4 and 5, shown on the precise grading plan, are in the approximate location as the bounda shown on the Hydrology Re ort for Parcel Ma ref TT TTM 36089 does not affect the existing ydrology program and the drainage areas and runoff remain similar to the results hown in the hydrology re ort. Please let us know if we can be of any assistance. Very truly yours, C�ZL Q 4(� -X702�_ Julian A De La Torre, PE Principal Engineer. '�- r: 1519,, KV 2 6 2008 CITY OF LA QIIINTA PLANNING DEPARTME 34200 BOB HOPE DRIVE ■ RANCHO MIRAGE ■ CALIFORNIA ■ 92270 760 - 320 -9811 ■ 760 - 323 -7893 FAX ■ WWW.MSACONSULTINGINC.COM ll�.�% Y t y �S• 1' — c -Lb-(108. Q-- PLANNING ■ CIVIL ENGINEERING ■ LANDISURVEYING November 26, 2008 Brian Ching, Associate Engineer Public Works /Development Services Division CITY OF LA QUINTA PO Box 1504 La Quinta CA 92247 -1504 Re: On -Site Hydrology for TTM 36089 and Review of Parcel Map 31116 Precise Grading Plans for Pool, Office Buildings, and Building'Nos. 1 -14 t: Dear Brian: With regard to the on -site hydrology requirements for TTM 36089, 1 have reviewed the Precise Grading Plans for Parcel Map 31116 - Pool, Office Buildings, and Building Nos. 1 -14. The ridgelines between Buildings 4 and 5, shown on the precise grading plan, are in the approximate location as the u bounda shown on the H drology �Re ort for Parcel Ma erefore, TTM 36089 does not affect the existing drology program and the drainage areas and runoff remain similar to the results shown in the hydrology re ort. Please let us know if we can be of any assistance. Very truly yours, Julian A De La Torre., PE Principal Engineer. 0'e- ,vi r.�5�. �0 NOV 2 6 ?_004 CITY OF LA QUINTA ANNING DEPARTMENT 34200 BOB HOPE DRIVE ■ RANCHO MIRAGE ■ CALIFORNIA ■ 92270 760 - 320 -9811 ■ 760 - 323 -7893 FAX ■ www.MSACONSULTINGINC.COM E -.`1 - . - I �Do P�, R/w R/w mm PIP o 0 �I it 41-N 0) �4 1 1W a