29436 Hidden CanyonFor Property Located
in La Quinta, California
RECEIVED
JUL 1 7 2003
PUBLIC WORKS
THE COVE AT LA QUINTA
TRACT 29436
Hydraulics Revised
June 24, 2003
Prepared for:
TRANSWEST HOUSING APIA
Br+r 7/i/a
Mainiero, Smith and Associates, Inc.
Planning / Civil Engineering /Land Surveying
777 East Tahquitz Canyon Way, Suite 301 / Palm Springs, California 92262-6784
Telephone (760) 320-9811 / FAX (760) 323-7893
Table of Contents
1. Hydrology Report (Narative)
2. 100 -Year Rational Method Calculations
3. 10 -Year Rational Method Calculations
4. Drainage Channel Calculations
5. Catch Basin Capacity Charts and Curb Opening Inlet Calculations
6. 100 -Year, 24 Hour and 1 -Hour Storm Maximum Water Surface Elevation in Detention
Basins
7. Culvert Capacity Charts
8. Storm Drain Hydraulic Grade Line Calculations
9. Unit Hydrograph Calculations
10. FEMA Map
11. Existing Hydrology Map
12. Rational Method Hydrology Map
13. Unit Hydrograph Hydrology Map
•
•
•
Introduction
The Cove at La Quinta project proposes 169 single family homes situated at the southern base of
the Indio Mountain. The project of 77 acres lies in the southeast quarter of Section 25, and the
northeast quarter of Section 36, Township 5 S., Range 6 E., and the southwest quarter of Section
30, Township 5 S., Range 7 E., all of the San Bernardino Meridian.
Existing Conditions
The Flood Insurance Rate Map (FIRM) Panel 060709 0005, Effective Date: August 19, 1991 for
Riverside County, prepared by the Federal Emergency Management Agency (FEMA), designates
the project site as Zone X. Zone X are areas of 500 -year flood; areas of 100 -year flood with
average depths of less than 1 foot or with drainage areas less than 1 square mile; and areas
protected by levees from the 100 -year flood (See FEMA Map).
The project site receives offsite flows from the adjacent mountain areas to the north and west.
Approximately 86 offsite acres are tributary to the site. Offsite areas consist of steep slopes.
Onsite (77 acres), the existing drainage pattern is in a southern direction. The onsite slopes are
mild. Offsite flows will collect at the base of the mountains and be conveyed southerly toward
Eisenhower Drive (See Existing Hydrology Map).
Hydrology Requirements
The City of La Quinta has flood control jurisdiction for this project. The City has required
(Conditions of Approval) that the project must retain 100 -percent of the onsite runoff in the 100 -
year, 24-hour storm. The City requires that runoff tributary to the adjacent public streets
(Eisenhower Drive) must be retained onsite. Consistent with current drainage law, the City will
allow offsite flows to be passed through the site. The City has not required off-site flows to be
retained onsite. The City requires that 10 -year peak flows must be conveyed below the top of
curb, and 100 -year peak flows must be conveyed within the public utility easement. This project
is similar to recent private developments, where the proposed right-of-way is just behind curb and
a public utility easement is 10 -feet behind curb. The final map for this project will provide for
drainage within the public utility easements. In most cases, flows are contained within the right-
of-way, and when exceeded the proposed public utility easement provides sufficient capacity.
Depth of flow within streets are calculated in the Rational Method program. The Rational Method
utilizes Manning's Equation to determine depth of flow. Desilting/detention and retention basins
shall not exceed 5 -feet in depth, unless prior approval has been granted. Desilting/Detention and
Retention Basins shall have one -foot of freeboard to adjacent pads. The storm drain system is
designed to maintain a hydraulic grade line (HGL) at or below the catch basin flowline.
Hydrologic and Hydraulic Methods
Hydrologic Methods - The Rational Method computer program based on the 1978 Riverside
County Flood Control & Water Conservation District Hydrology Manual was used to determine the
peak runoff flows in the 10 -year and 100 -year one-hour storms. The Los Angeles District U.S.
Corps of Engineers Methodology for Debris Production was used to establish the debris volume
and bulking factor associated with the offsite flows (See Rational Method Calculations and
Hydrology Map). Drainage channels along the base of the mountain intercept flows from the
mountain. Drainage Channel Calculations are provided using Manning's Equation (see Drainage
Channel Calculations). The Synthetic Unit Hydrograph computer program based on the 1978
Riverside County Flood Control & Water Conservation District Hydrology Manual was used to
establish the runoff volumes tributary to the desilting/detention and retention basins in the 100 -
year, 24-hour storm. For areas less than 10 acres (Basin 4), the Shortcut Method Synthetic Unit
Hydrograph was used to establish the runoff volume (See Unit Hydrograph Calculations and
Hydrology Map).
•
•
•
Hydraulic Methods - Figure 33 of the Concrete Pipe Manual was used to determine the required
headwater to convey the peak flows in the culverts crossings at Nodes 1104 and 1105 (See
Culvert Capacity Charts). The headwater depths established the maximum water surface
upstream of the culverts and the beginning hydraulic grade line for the storm drain systems at
Nodes 302, 1103, 1403, and 1702. The beginning hydraulic grade line for storm drain systems at
Nodes 105 and 1802 is the maximum water surface in Detention Basin 5. The beginning
hydraulic grade line for storm drain systems at Nodes 1902, 2002, 2104 and 2204 is the
maximum water surface in Detention Basin 7 and 8 (See 100 -year, 1 -hour Maximum, Water
Surface Elevation for Detention Basins). The Catch Basin Connecting Pipes Capacity Charts
were used to determine the hydraulic grade line of the storm drain systems (see Storm Drain
Hydraulic Grade Line Calculations). The Catch Basin Capacity Charts were used to determine
the required width to capture the 100 -year peak flows (See Catch Basin Capacity Charts). The
depths of flow within the streets are calculated in the Rational Method program.
Proposed Flood Control Improvements
In the 100 -year, 1 -hour storm, runoff (including bulked flows) from Drainage Areas B, C and G are
conveyed to the Desilting/Detention Basins 6, 1 and 4 respectfully, flows are detained in the
desilting/detention basins then overflow and ultimately drain to Detention Basin 5. The time of
concentration is delayed in proportion to the capacity of the retention basin. For example, if the
detention basin has the capacity to retain one-half of the 100 -year, 1 -hour storm (1.6 -inches), the
time of concentration would increase to one-half hour. Desilting/detention Basins 2, 3, and 5
have the capacity to retain the 100 -year, 1 -hour storm runoff; these basins do not contribute
runoff in the rational method calculations. Detention Basin 3 has the capacity to retain the 100 -
year, 24-hour storm (4.5 -inches of rainfall) and doesn't contribute runoff to detention basin 5.
Runoff that exceeds the capacities of the detention basins during the 100 -year, 24-hour storm will
safely overflow the basin through overflow structures or pipe systems and be conveyed to
detention basin 5.
Results
The Rational Method results indicate that the 10 -year peak flows are conveyed within the streets
and below the top of curb, and the 100 -year peak flows are conveyed within the public utility
easement. The Synthetic Unit Hydrograph results indicate that the desilting/detention basins 1, 2,
4 and 6 overflow 4.68, 4.08, 0.43 and 5.13 acre-feet respectfully, to Detention Basin 5. Detention
Basin 5 has 16.59 acre-feet of runoff tributary to it (total 30.91 acre-feet). Detention Basin 5 has
23.87 acre-feet of capacity; therefore 7.04 acre-feet overflow Detention Basin 5. Unit Hydrograph
calculations indicate that the "Offsite and Onsite" Unit Hydrograph generates 32.66 acre-feet of
runoff. The "Onsite Only' Unit Hydrograph calculations indicate 15.54 acre-feet are generated
onsite and are required to be retained by the project. The Culvert Capacity Charts indicate that
the culverts will convey the peak flows below the streets. The Storm Drain Hydraulic Grade Line
Calculation results indicate that the Hydraulic Grade Line is below the normal curb flowline.
Catch Basin Capacity Charts results indicate that peak flows are captured by the proposed catch
basins.
Conclusion
In conclusion, the proposed development of The Cove at La Quinta will significantly improve the
existing drainage conditions by providing desilting/detention basins for 36.22 acre-feet (only
required to retain 15.54 acre-feet) and safely overflow 7.14 acre-feet to Eisenhower Drive, and
providing a safe overflow for off-site storm runoff and storms larger than the 100 -year event.
RATIONAL METHOD CALCULATIONS
100 YEAR STORM
•
•
RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM BASED ON
RIVERSIDE COUNTY FLOOD CONTROL & WATER CONSERVATION DISTRICT
(RCFC&WCD) 1978 HYDROLOGY MANUAL
(c) Copyright 1982-94 Advanced Engineering Software (aes)
Ver. 1.5A Release Date: 6/01/94 License ID 1304
Analysis prepared by:
MAINIERO, SMITH & ASSOCIATES, INC.
CIVIL & ENVIRONMENTAL ENGINEERING, SURVEYING AND LAND PLANNING
777 TAHQUIST CANYON WAY, SUITE 301
PALM SPRINGS, CALIFORNIA 92262-7066
DESCRIPTION OF STUDY
* The Cove at La Quinta, US Home
* 100 Year Storm
* Offsite and Onsite Runoff
FILE NAME: 1348P.DAT
TIME/DATE OF STUDY: 12:11 3/27/2003
USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
USER SPECIFIED STORM EVENT(YEAR) = 100.00
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = .95
2 -YEAR, 1 -HOUR PRECIPITATION(INCH) = .500
100 -YEAR, 1 -HOUR PRECIPITATION(INCH) = 1.600
COMPUTED RAINFALL INTENSITY DATA:
STORM EVENT = 100.00 1 -HOUR INTENSITY(INCH/HOUR) = 1.6000
SLOPE OF INTENSITY DURATION CURVE = .6000
RCFC&WCD HYDROLOGY MANUAL "C" -VALUES USED
NOTE: COMPUTE CONFLUENCE VALUES ACCORDING TO RCFC&WCD HYDROLOGY MANUAL
AND IGNORE OTHER CONFLUENCE COMBINATIONS FOR DOWNSTREAM ANALYSES
FLOW PROCESS FROM NODE 101.00 TO NODE 102.00 IS CODE = 21
» »>RATIONAL METHOD INITIAL SUBAREA ANALYSIS « « <
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS: UNDEVELOPED WITH POOR COVER
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 500.00
UPSTREAM ELEVATION = 260.00
DOWNSTREAM ELEVATION = 49.21
ELEVATION DIFFERENCE = 210.79
TC = .533*[( 500.00**3)/( 210.79)]**.2 = 7.603
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.526
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT =.8330
SUBAREA RUNOFF(CFS) = 8.33
TOTAL AREA(ACRES) = 1.81 TOTAL RUNOFF(CFS) =
8.33
FLOW PROCESS FROM NODE 102.00 TO NODE 103.00 IS CODE = 51
» »>COMPUTE TRAPEZOIDAL CHANNEL FLOW« «<
» »>TRAVELTIME THRU SUBAREA« « <
• UPSTREAM NODE ▪ ELEVATION = 49.21
DOWNSTREAM NODE ELEVATION = 47.70
CHANNEL LENGTH THRU SUBAREA(FEET) = 240.00
CHANNEL SLOPE = .0063
CHANNEL BASE(FEET) = 00 "Z" FACTOR = 1.250
MANNING'S FACTOR = .015 MAXIMUM DEPTH(FEET) = 2.00
•
•
•
CHANNEL FLOW THRU SUBAREA(CFS) = 8.33
FLOW VELOCITY(FEET/SEC) = 4.73 FLOW DEPTH(FEET) = 1.19
TRAVEL TIME(MIN.) _ .85 TC(MIN.) = 8.45
FLOW PROCESS FROM NODE 103.00 TO NODE 103.00 IS CODE = 8
» » >ADDITION OF SUBAREA TO MAINLINE PEAK FLOW« «<
__ =
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.187 _
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8290
SUBAREA AREA(ACRES) = 1.86 SUBAREA RUNOFF(CFS) - 8.00
TOTAL AREA(ACRES) = 3.67 TOTAL RUNOFF(CFS) = 16.33
TC(MIN) = 8.45
FLOW PROCESS FROM NODE 103.00 TO NODE 103.00 IS CODE = 7
» » >USER SPECIFIED HYDROLOGY INFORMATION AT NODE« «<
USER-SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 8.45 RAIN INTENSITY(INCH/HOUR) = 5.19
TOTAL AREA(ACRES) = 3.67 TOTAL RUNOFF(CFS) =
17.31
*141016.f * * .**4f,***MAP
FLOW PROCESS FROM NODE 103.00 TO NODE 105.00 IS CODE = 4
» »>COMPUTE PIPEFLOW TRAVELTIME THRU SUBAREA« « <
» » >USING USER-SPECIFIED PIPESIZE« « <
DEPTH OF FLOW IN 30.0 INCH PIPE I5 17.0 INCHES
PIPEFLOW VELOCITY(FEET/SEC.) = 6.0
UPSTREAM NODE ELEVATION = 44.44
DOWNSTREAM NODE ELEVATION = 43.54
FLOWLENGTH(FEET) = 180.00 MANNING'S N = .013
GIVEN PIPE DIAMETER(INCH) = 30.00 NUMBER OF PIPES = 1
PIPEFLOW THRU SUBAREA(CFS) = 17.31
TRAVEL TIME(MIN.) = .50 TC(MIN.) = 8.95
FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE = 1
» »>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE« « <
===== _
TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:
TIME OF CONCENTRATION(MIN.) = 8.95
RAINFALL INTENSITY(INCH/HR) = 5.01
TOTAL STREAM AREA(ACRES) = 3.67
PEAK FLOW RATE(CFS) AT CONFLUENCE = 17.31
FLOW PROCESS FROM NODE 111.00 TO NODE 105.00 IS CODE = 21
» »>RATIONAL METHOD INITIAL SUBAREA ANALYSIS « « <
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS SINGLE FAMILY (1/4 ACRE)
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 710.00
UPSTREAM ELEVATION = 52.40
DOWNSTREAM ELEVATION = 47.63
ELEVATION DIFFERENCE = 4.77
TC = .393*[( 710.00**3)/( 4.77)]**.2 = 14.757
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.712
•
•
•
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8519
SUBAREA RUNOFF(CFS) = 8.82
TOTAL AREA(ACRES) = 2.79 TOTAL RUNOFF(CFS) =
8.82
FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE = 1
» »>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE« «<
TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:
TIME OF CONCENTRATION(MIN.) = 14.76
RAINFALL INTENSITY(INCH/HR) = 3.71
TOTAL STREAM AREA(ACRES) = 2.79
PEAK FLOW RATE(CFS) AT CONFLUENCE = 8.82
FLOW PROCESS FROM NODE 121.00 TO NODE 105.00 IS CODE = 21
» » >RATIONAL METHOD INITIAL SUBAREA ANALYSIS« « <
ASSUMED INITIAL SUBAREA UNIFORM=
DEVELOPMENT IS SINGLE FAMILY (1/4 ACRE)
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 680.00
UPSTREAM ELEVATION = 52.30
DOWNSTREAM ELEVATION = 47.63
ELEVATION DIFFERENCE = 4.67
TC = .393*(( 680.00**3)/( 4.67)]**.2 = 14.441
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.761
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8524
SUBAREA RUNOFF(CFS) = 7.82
TOTAL AREA(ACRES) = 2.44 TOTAL RUNOFF(CFS) = 7.82
FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE = 1
» »>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE« « <
» » >AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES« « <
TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 3 ARE:
TIME OF CONCENTRATION(MIN.) = 14.44
RAINFALL INTENSITY(INCH/HR) = 3.76
TOTAL STREAM AREA(ACRES) = 2.44
PEAK FLOW RATE(CFS) AT CONFLUENCE = 7.82
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 17.31 8.95 5.012 3.67
2 8.82 14.76 3.712 2.79
3 7.82 14.44 3.761 2.44
WARNING
IN THIS COMPUTER PROGRAM, THE CONFLUENCE VALUE USED IS BASED
ON THE RCFC&WCD FORMULA OF PLATE D-1 AS DEFAULT VALUE. THIS FORMULA
WILL NOT NECESSARILY RESULT IN THE MAXIMUM VALUE OF PEAK FLOW.
RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 3 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
•
•
1 27.50 8.95 5.012
2 29.44 14.44 3.761
3 29.36 14.76 3.712
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:
PEAK FLOW RATE(CFS) = 27.50 TC(MIN.) = 8.95
TOTAL AREA(ACRES) = 8.90
FLOW PROCESS FROM NODE 201.00 TO NODE 201.00 IS CODE = 21
» » ,RATIONAL METHOD INITIAL SUBAREA ANALYSIS« « <
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS: UNDEVELOPED WITH POOR COVER
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 740.00
UPSTREAM ELEVATION = 340.00
DOWNSTREAM ELEVATION = 50.58
ELEVATION DIFFERENCE = 289.42
TC = .533*(( 740.00**3)/( 289.42)]**.2 = 9.029
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.985
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8263
SUBAREA RUNOFF(CFS) = 10.21
TOTAL AREA(ACRES) = 2.48 TOTAL RUNOFF(CFS) =
10.21
FLOW PROCESS FROM NODE 202.00 TO NODE 202.00 IS CODE = 7
» » ,USER SPECIFIED HYDROLOGY INFORMATION AT NODE« « <
USER-SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 9.03 RAIN INTENSITY(INCH/HOUR) = 4.98
TOTAL AREA(ACRES) = 2.48 TOTAL RUNOFF(CFS) =
11.03
FLOW PROCESS FROM NODE 202.00 TO NODE 203.00 IS CODE = 4
» » ,COMPUTE PIPEFLOW TRAVELTIME THRU SUBAREA« « <
» »,USING USER-SPECIFIED PIPESIZE« « <
PIPEFLOW VELOCITY(FEET/SEC.) = 6.2
UPSTREAM NODE ELEVATION = 44.70
DOWNSTREAM NODE ELEVATION = 43.50
FLOWLENGTH(FEET) = 240.00 MANNING'S N = .013
GIVEN PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1
PIPEFLOW THRU SUBAREA(CFS) = 11.03
TRAVEL TIME(MIN.) = .64 TC(MIN.) = 9.67
FLOW PROCESS FROM NODE 401.00 TO NODE 402.00 IS CODE 21
» »,RATIONAL METHOD INITIAL SUBAREA ANALYSIS« « <
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS: UNDEVELOPED WITH POOR COVER
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 1000.00
UPSTREAM ELEVATION = 1000.00
DOWNSTREAM ELEVATION = 180.00
ELEVATION DIFFERENCE = 820.00
TC = .533*(( 1000.00**3)/( 820.00)]**.2 = 8.783
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.068
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8274
SUBAREA RUNOFF(CFS) = 23.94
•
•
•
TOTAL AREA(ACRES) _
5.71 TOTAL RUNOFF(CFS) = 23.94
FLOW PROCESS FROM NODE 402.00 TO NODE 403.00 IS CODE = 53
» » >COMPUTE NATURAL MOUNTAIN CHANNEL FLOW« « <
» » >TRAVELTIME THRU SUBAREA« « <
UPSTREAM NODE ELEVATION = 180.00
DOWNSTREAM NODE ELEVATION = 67.60
CHANNEL LENGTH THRU SUBAREA(FEET) = 320.00
CHANNEL SLOPE = .3512
CHANNEL FLOW THRU SUBAREA(CFS) = 23.94
SLOPE ADJUSTMENT CURVE USED: EFFECTIVE SLOPE = .2055 (PER PLATE D-6.2)
FLOW VELOCITY(FEET/SEC) = 7.31 (PER PLATE D-6.3)
TRAVEL TIME(MIN.) = .73 TC(MIN.) = 9.51
FLOW PROCESS FROM NODE 403.00 TO NODE 403.00 IS CODE = 8
» » >ADDITION OF SUBAREA TO MAINLINE PEAK FLOW«« <
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.831
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8242
SUBAREA AREA(ACRES) = 9.24 SUBAREA RUNOFF(CFS) = 36.79
TOTAL AREA(ACRES) = 14.95 TOTAL RUNOFF(CFS) 60.73
TC(MIN) = 9.51
FLOW PROCESS FROM NODE 403.00 TO NODE 404.00 IS CODE = 51
» » >COMPUTE TRAPEZOIDAL CHANNEL FLOW« «<
» »>TRAVELTIME THRU SUBAREA« « <
UPSTREAM NODE ELEVATION = 62.70
DOWNSTREAM NODE ELEVATION = 55.00
CHANNEL LENGTH THRU SUBAREA(FEET) = 705.00
CHANNEL SLOPE _ .0109
CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = .000
MANNING'S FACTOR = .015 MAXIMUM DEPTH(FEET) = 2.00
CHANNEL FLOW THRU SUBAREA(CFS) = 60.73
FLOW VELOCITY(FEET/SEC) = 9.33 FLOW DEPTH(FEET) = 1.30
TRAVEL TIME(MIN.) = 1.26 TC(MIN.) = 10.77
FLOW PROCESS FROM NODE 404.00 TO NODE 404.00 IS CODE = 8
» »>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW« «<
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.484
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8188
SUBAREA AREA(ACRES) = 7.47 SUBAREA RUNOFF(CFS) = 27.43
TOTAL AREA(ACRES) = 22.42 TOTAL RUNOFF(CFS) = 88.16
TC(MIN) = 10.77
FLOW PROCESS FROM NODE 401.00 TO NODE 502.00 IS CODE = 21
» »>RATIONAL METHOD INITIAL SUBAREA ANALYSIS« « <
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS: UNDEVELOPED WITH POOR COVER
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 1000.00
•
•
•
UPSTREAM ELEVATION = 1000.00
DOWNSTREAM ELEVATION = 240.00
ELEVATION DIFFERENCE = 760.00
TC = .533*[( 1000.00**3)/( 760.00)]**.2 = 8.917
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.022
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8268
SUBAREA RUNOFF(CFS) = 23.92
TOTAL AREA(ACRES) = 5.76 TOTAL RUNOFF(CFS)
23.92
FLOW PROCESS FROM NODE 502.00 TO NODE 503.00 IS CODE = 53
» » >COMPUTE NATURAL MOUNTAIN CHANNEL FLOW« « «
» » >TRAVELTIME THRU SUBAREA« «<
UPSTREAM NODE ELEVATION = 240.00
DOWNSTREAM NODE ELEVATION = 80.00
CHANNEL LENGTH THRU SUBAREA(FEET) = 500.00
CHANNEL SLOPE _ .3200
CHANNEL FLOW THRU SUBAREA(CFS) = 23.92
SLOPE ADJUSTMENT CURVE USED: EFFECTIVE SLOPE _ .2000 (PER PLATE D-6.2)
FLOW VELOCITY(FEET/SEC) = 7.21 (PER PLATE D-6.3)
TRAVEL TIME(MIN.) = 1.16 TC(MIN.) = 10.07
FLOW PROCESS FROM NODE 503.00 TO NODE 503.00 IS CODE = 8
» »>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW« « <
=
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.668
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8218
SUBAREA AREA(ACRES) = 10.72 SUBAREA RUNOFF(CFS) = 41.12
TOTAL AREA(ACRES) = 16.48 TOTAL RUNOFF(CFS) = 65.04
TC(MIN) = 10.07
FLOW PROCESS FROM NODE 503.00 TO NODE 503.00 IS CODE = 8
» » >ADDITION OF SUBAREA TO MAINLINE PEAK FLOWc « <c
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.668
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8218
SUBAREA AREA(ACRES) = 4.72 SUBAREA RUNOFF(CFS) = 18.10
TOTAL AREA(ACRES) = 21.20 TOTAL RUNOFF(CFS) = 83.14
TC(MIN) = 10.07
FLOW PROCESS FROM NODE 701.00 TO NODE 702.00 IS CODE = 21
» » >RATIONAL METHOD INITIAL SUBAREA ANALYSIS« «<
===11=====__=====W1d====.____
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS: UNDEVELOPED WITH POOR COVER
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 1000.00
UPSTREAM ELEVATION = 610.00
DOWNSTREAM ELEVATION = 70.00
ELEVATION DIFFERENCE = 540.00
TC = .533*[( 1000.00**3)/( 540.00)]**.2 = 9.548
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.820
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8240
SUBAREA RUNOFF(CFS) = 35.55
TOTAL AREA(ACRES) = 8.95 TOTAL RUNOFF(CFS) =
35.55
•
•
•
FLOW PROCESS FROM NODE 702.00 TO NODE 702.00 IS CODE = 8
» » >ADDITION OF SUBAREA TO MAINLINE PEAK FLOW« « <
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.820
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8240
SUBAREA AREA(ACRES) = 16.32 SUBAREA RUNOFF(CFS) = 64.82
TOTAL AREA(ACRES) = 25.27 TOTAL RUNOFF(CFS) = 100.37
TC(MIN) = 9.55
FLOW PROCESS FROM NODE 702.00 TO NODE 702.00 IS CODE = 8
» » >ADDITION OF SUBAREA TO MAINLINE PEAK FLOW« « <
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.820
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8240
SUBAREA AREA(ACRES) = 5.68 SUBAREA RUNOFF(CFS) = 22.56
TOTAL AREA(ACRES) = 30.95 TOTAL RUNOFF(CFS) = 122.93
TC(MIN) = 9.55
FLOW PROCESS FROM NODE 801.00 TO NODE 802.00 IS CODE = 21
» » >RATIONAL METHOD INITIAL SUBAREA ANALYSIS« «<
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS: UNDEVELOPED WITH POOR COVER
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 650.00
UPSTREAM ELEVATION = 460.00
DOWNSTREAM ELEVATION = 60.00
ELEVATION DIFFERENCE = 400.00
TC = .533*[( 650.00**3)/( 400.00)]**.2 = 7.830
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.430
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8319
SUBAREA RUNOFF(CFS) = 17.80
TOTAL AREA(ACRES) = 3.94 TOTAL RUNOFF(CFS) =
17.80
FLOW PROCESS FROM NODE 802.00 TO NODE 802.00 IS CODE = 8
» »>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW< « «
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.430
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8319
SUBAREA AREA(ACRES) = 5.98 SUBAREA RUNOFF(CFS) = 27.01
TOTAL AREA(ACRES) = 9.92 TOTAL RUNOFF(CFS) = 44.81
TC(MIN) = 7.83
FLOW PROCESS FROM NODE 901.00 TO NODE 902.00 IS CODE = 21
» »>RATIONAL METHOD INITIAL SUBAREA ANALYSIS « « <
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS: UNDEVELOPED WITH POOR COVER
TC = K*[(LENGTH**3)/(ELEVATION CHANGE))**.2
INITIAL SUBAREA FLOW -LENGTH = 500.00
UPSTREAM ELEVATION = 270.00
•
•
•
DOWNSTREAM ELEVATION = 58.00
ELEVATION DIFFERENCE = 212.00
TC = .533*[( 500.00**3)/( 212.00)]**.2 = 7.595
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.530
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8330
SUBAREA RUNOFF(CFS) = 5.76
TOTAL AREA(ACRES) = 1.25 TOTAL RUNOFF(CFS) =
5.76
****************************************************************************
FLOW PROCESS FROM NODE 902.00 TO NODE 902.00 IS CODE = 8
» > »ADDITION OF SUBAREA TO MAINLINE PEAK FLOW« «<
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.530
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8330
SUBAREA AREA(ACRES) = 1.37 SUBAREA RUNOFF(CFS) = 6.31
TOTAL AREA(ACRES) = 2.62 TOTAL RUNOFF(CFS) = 12.07
TC(MIN) = 7.59
FLOW PROCESS FROM NODE 1101.00 TO NODE 1102.00 IS CODE = 21
» »>RATIONAL METHOD INITIAL SUBAREA ANALYSIS « cc<
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS SINGLE FAMILY (1/4 ACRE)
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 800.00
UPSTREAM ELEVATION = 57.30
DOWNSTREAM ELEVATION = 51.91
ELEVATION DIFFERENCE = 5.39
TC = .393*[( 800.00**3)/( 5.39)]**.2 = 15.470
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.608
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8507
SUBAREA RUNOFF(CFS) = 10.87
TOTAL AREA(ACRES) = 3.54 TOTAL RUNOFF(CFS) =
10.87
FLOW PROCESS FROM NODE 1102.00 TO NODE 1103.00 IS CODE = 6
» »>COMPUTE STREETFLOW TRAVELTIME THRU SUBAREA« «<
== x==a==$__
UPSTREAM ELEVATION = 51.91 DOWNSTREAM ELEVATION = _ 48.49
STREET LENGTH(FEET) = 665.00 CURB HEIGHT(INCHES) = 6.
STREET HALFWIDTH(FEET) = 18.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK = 9.00
INTERIOR STREET CROSSFALL(DECIMAL) = .020
OUTSIDE STREET CROSSFALL(DECIMAL) = .020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 2
**TRAVELTIME COMPUTED USING MEAN FLOW(CFS) = 15.57
***STREET FLOWING FULL***
STREETFLOW MODEL RESULTS:
STREET FLOWDEPTH(FEET) _ .50
HALFSTREET FLOODWIDTH(FEET) = 18.00
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.20
PRODUCT OF DEPTH&VELOCITY = 1.09
STREETFLOW TRAVELTIME(MIN) = 5.03 TC(MIN) = 20.50
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.047
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8427
SUBAREA AREA(ACRES) = 3.63 SUBAREA RUNOFF(CFS) =
9.32
•
•
•
SUMMED AREA(ACRES) = 7.17 TOTAL RUNOFF(CFS) = 20.19
END OF SUBAREA STREETFLOW HYDRAULICS:
DEPTH(FEET) = .52 HALFSTREET FLOODWIDTH(FEET) = 18.00
FLOW VELOCITY(FEET/SEC.) = 2.60 DEPTH*VELOCITY = 1.34
FLOW PROCESS FROM NODE 1103.00 TO NODE 1103.00 IS CODE = 1
» » >DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE« « <
TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:
TIME OF CONCENTRATION(MIN.) = 20.50
RAINFALL INTENSITY(INCH/HR) = 3.05
TOTAL STREAM AREA(ACRES) = 7.17
PEAK FLOW RATE(CFS) AT CONFLUENCE = 20.19
FLOW PROCESS FROM NODE 504.00 TO NODE 504.00 IS CODE = 7
» »>USER SPECIFIED HYDROLOGY INFORMATION AT NODE« « <
USER-SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 26.00 RAIN INTENSITY(INCH/HOUR) = 2.64
TOTAL AREA(ACRES) = 21.20 TOTAL RUNOFF(CFS) = 42.44
FLOW PROCESS FROM NODE 504.00 TO NODE 1103.00 IS CODE = 6
» »>COMPUTE STREETFLOW TRAVELTIME THRU SUBAREA« «<
UPSTREAM ELEVATION = 54.84 DOWNSTREAM ELEVATION = 48.49
STREET LENGTH(FEET) = 550.00 CURB HEIGHT(INCHES) = 6.
STREET HALFWIDTH(FEET) = 18.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK = 9.00
INTERIOR STREET CROSSFALL(DECIMAL) _ .020
OUTSIDE STREET CROSSFALL(DECIMAL) _ .020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 2
**TRAVELTIME COMPUTED USING MEAN FLOW(CFS) = 47.58
***STREET FLOWING FULL***
STREETFLOW MODEL RESULTS:
NOTE: STREETFLOW EXCEEDS TOP OF CURB.
THE FOLLOWING STREETFLOW RESULTS ARE BASED ON THE ASSUMPTION
THAT NEGLIBLE FLOW OCCURS OUTSIDE OF THE STREET CHANNEL.
THAT IS, ALL FLOW ALONG THE PARKWAY, ETC., IS NEGLECTED.
STREET FLOWDEPTH(FEET) = .59
HALFSTREET FLOODWIDTH(FEET) = 18.00
AVERAGE FLOW VELOCITY(FEET/SEC.) = 4.50
PRODUCT OF DEPTH&VELOCITY = 2.67
STREETFLOW TRAVELTIME(MIN) = 2.04 TC(MIN) = 28.04
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.526
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8327
SUBAREA AREA(ACRES) = 4.89 SUBAREA RUNOFF(CFS) = 10.28
SUMMED AREA(ACRES) = 26.09 TOTAL RUNOFF(CFS) = 52.72
END OF SUBAREA STREETFLOW HYDRAULICS:
DEPTH(FEET) = .61 HALFSTREET FLOODWIDTH(FEET) = 18.00
FLOW VELOCITY(FEET/SEC.) = 4.67 DEPTH*VELOCITY = 2.86
FLOW PROCESS FROM NODE 1103.00 TO NODE 1103.00 IS CODE = 1
» »>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE« «<
•
•
•
» » >AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES« « <
TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:
TIME OF CONCENTRATION(MIN.) = 28.04
RAINFALL INTENSITY(INCH/HR) = 2.53
TOTAL STREAM AREA(ACRES) = 26.09
PEAK FLOW RATE(CFS) AT CONFLUENCE = 52.72
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 20.19 20.50 3.047 7.17
2 52.72 28.04 2.526 26.09
WARNING
IN THIS COMPUTER PROGRAM, THE CONFLUENCE VALUE USED IS BASED
ON THE RCFC&WCD FORMULA OF PLATE D-1 AS DEFAULT VALUE. THIS FORMULA
WILL NOT NECESSARILY RESULT IN THE MAXIMUM VALUE OF PEAK FLOW.
RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 58.74 20.50 3.047
2 69.45 28.04 2.526
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:
PEAK FLOW RATE(CFS) = 69.45 Tc(MIN.) = 28.04
TOTAL AREA(ACRES) = 33.26
FLOW PROCESS FROM NODE 1103.00 TO NODE 1103.50 IS CODE = 1
» » >DESIGNATE INDEPENDENT STREAM FOR CONFLUENCEc « «
TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:
TIME OF CONCENTRATION(MIN.) = 28.04
RAINFALL INTENSITY(INCH/HR) = 2.53
TOTAL STREAM AREA(ACRES) = 33.26
PEAK FLOW RATE(CFS) AT CONFLUENCE = 69.45
FLOW PROCESS FROM NODE 601.00 TO NODE 602.00 IS CODE = 21
» »>RATIONAL METHOD INITIAL SUBAREA ANALYSIS« « <
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS: UNDEVELOPED WITH POOR COVER
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 450.00
UPSTREAM ELEVATION = 320.00
DOWNSTREAM ELEVATION = 62.63
ELEVATION DIFFERENCE = 257.37
TC = .533*[( 450.00**3)/( 257.37)]**.2 = 6.858
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.879
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8367
SUBAREA RUNOFF(CFS) = 5.61
TOTAL AREA(ACRES) = 1.14 TOTAL RUNOFF(CFS) = 5.61
FLOW PROCESS FROM NODE 602.00 TO NODE 603.00 IS CODE = 51
•
•
•
» » >COMPUTE TRAPEZOIDAL CHANNEL FLOW« « <
» »>TRAVELTIME THRU SUBAREA« « <
UPSTREAM NODE ELEVATION = 62.63
DOWNSTREAM NODE ELEVATION = 52.95
CHANNEL LENGTH THRU SUBAREA(FEET) = 190 00
CHANNEL SLOPE = .0509
CHANNEL BASE(FEET) = .00 "Z" FACTOR = 1.250
MANNING'S FACTOR = .015 MAXIMUM DEPTH(FEET) = 2.00
CHANNEL FLOW THRU SUBAREA(CFS) = 5.61
FLOW VELOCITY(FEET/SEC) = 9.38 FLOW DEPTH(FEET) = .69
TRAVEL TIME(MIN.) = .34 TC(MIN.) = 7.20
FLOW PROCESS FROM NODE 603.00 TO NODE 603.00 IS CODE = 8
» »>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW« « <
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.712
SOIL CLASSIFICATION IS "D"
UNDEVELOPED WATERSHED RUNOFF COEFFICIENT = .8350
SUBAREA AREA(ACRES) = .60 SUBAREA RUNOFF(CFS) = 2.86
TOTAL AREA(ACRES) = 1.74 TOTAL RUNOFF(CFS) = 8.47
TC(MIN) = 7.20
FLOW PROCESS FROM NODE 603.00 TO NODE 603.00 IS CODE = 7
» » >USER SPECIFIED HYDROLOGY INFORMATION AT NODE« « <
USER-SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 7.20 RAIN INTENSITY(INCH/HOUR) = 5.71
TOTAL AREA(ACRES) = 1.74 TOTAL RUNOFF(CFS) = 9.06
!* * ** **..aF x.0'1 4*.**►***�*.N4o�'
FLOW PROCESS FROM NODE 603.00 TO NODE 604.00 IS CODE = 4
» »>COMPUTE PIPEFLOW TRAVELTIME THRU SUBAREA« « <
» » >USING USER-SPECIFIED PIPESIZE« «<
==
DEPTH OF FLOW IN 24.0 INCH PIPE IS 13.1 INCHES
PIPEFLOW VELOCITY(FEET/SEC.) = 5.1
UPSTREAM NODE ELEVATION = 43.61
DOWNSTREAM NODE ELEVATION = 43.01
FLOWLENGTH(FEET) = 120.00 MANNING'S N = .013
GIVEN PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1
PIPEFLOW THRU SUBAREA(CFS) = 9.06
TRAVEL TIME(MIN.) = .39 TC(MIN.) = 7.59
FLOW PROCESS FROM NODE 604.00 TO NODE 1103.50 IS CODE = 1
» »>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE« « <
» »>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES« «<
TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:
TIME OF CONCENTRATION(MIN.) = 7.59
RAINFALL INTENSITY(INCH/HR) = 5.53
TOTAL STREAM AREA(ACRES) = 1.74
PEAK FLOW RATE(CFS) AT CONFLUENCE = 9.06
** CONFLUENCE DATA **
STREAM RUNOFF TC INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 69.45 28.04 2.526 33.26
2 9.06 7.59 5.532 1.74
•
•
•
WARNING
IN THIS COMPUTER PROGRAM, THE CONFLUENCE VALUE USED IS BASED
ON THE RCFC&WCD FORMULA OF PLATE D-1 AS DEFAULT VALUE. THIS FORMULA
WILL NOT NECESSARILY RESULT IN THE MAXIMUM VALUE OF PEAK FLOW.
RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 27.86 7.59 5.532
2 73.59 28.04 2.526
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:
PEAK FLOW RATE(CFS) 73.59 TC(MIN.) = 28.04
TOTAL AREA(ACRES) = 35.00
FLOW PROCESS FROM NODE 1103.50 TO NODE 1104.00 IS CODE = 1
» » >DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE« « <
TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:
TIME OF CONCENTRATION(MIN.) = 28.04
RAINFALL INTENSITY(INCH/HR) = 2.53
TOTAL STREAM AREA(ACRES) = 35.00
PEAK FLOW RATE(CFS) AT CONFLUENCE = 73.59
FLOW PROCESS FROM NODE 903.00 TO NODE 903.00 IS CODE = 7
» » >USER SPECIFIED HYDROLOGY INFORMATION AT NODE« « <
=az= _= _ ___ -55
USER-SPECIFIED
USER-SPECIFIED VALUES ARE AS FOLLOWS:
TC(MIN) = 42.00 RAIN INTENSITY(INCH/HOUR) = 1.98
TOTAL AREA(ACRES) = 2.62 TOTAL RUNOFF(CFS) =
3.82
FLOW PROCESS FROM NODE 903.00 TO NODE 904.00 IS CODE = 6
» »>COMPUTE STREETFLOW TRAVELTIME THRU SUBAREA« «<
UPSTREAM ELEVATION = 54.11 DOWNSTREAM ELEVATION = 52.47
STREET LENGTH(FEET) = 150.00 CURB HEIGHT(INCHES) = 6.
STREET HALFWIDTH(FEET) = 18.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK = 9.00
INTERIOR STREET CROSSFALL(DECIMAL) = .020
OUTSIDE STREET CROSSFALL(DECIMAL) = .020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
**TRAVELTIME COMPUTED USING MEAN FLOW(CFS) =
STREETFLOW MODEL RESULTS:
STREET FLOWDEPTH(FEET) = .37
HALFSTREET FLOODWIDTH(FEET) = 12.07
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.56
PRODUCT OF DEPTH&VELOCITY = .94
STREETFLOW TRAVELTIME(MIN) = .98 TC(MIN) = 42.98
4.03
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 1.955
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8166
SUBAREA AREA(ACRES) = .26 SUBAREA RUNOFF(CFS) = .42
•
•
•
SUMMED AREA(ACRES) = 2.88 TOTAL RUNOFF(CFS) =
END OF SUBAREA STREETFLOW HYDRAULICS:
DEPTH(FEET) = .37 HALFSTREET FLOODWIDTH(FEET) = 12.07
FLOW VELOCITY(FEET/SEC.) = 2.69 DEPTH*VELOCITY = .99
4.24
FLOW PROCESS FROM NODE 904.00 TO NODE 904.00 IS CODE = 8
» » >ADDITION OF SUBAREA TO MAINLINE PEAK FLOW« «<
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 1.955
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8166
SUBAREA AREA(ACRES) = 2.90 SUBAREA RUNOFF(CFS) = 4.63
TOTAL AREA(ACRES) = 5.78 TOTAL RUNOFF(CFS) = 8.86
TC(MIN) = 42.98
FLOW PROCESS FROM NODE 904.00 TO NODE 905.00 IS CODE = 6
» » >COMPUTE STREETFLOW TRAVELTIME THRU SUBAREA« «<
UPSTREAM ELEVATION = 52.47
STREET LENGTH(FEET) = 150.00 CURB HEIGHT(INCHES) = 6.
STREET HALFWIDTH(FEET) = 18.00
DOWNSTREAM ELEVATION = 51.71
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK = 9.00
INTERIOR STREET CROSSFALL(DECIMAL) = .020
OUTSIDE STREET CROSSFALL(DECIMAL) _ .020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
**TRAVELTIME COMPUTED USING MEAN FLOW(CFS) =
***STREETFLOW SPLITS OVER STREET -CROWN***
FULL DEPTH(FEET) = .49 FLOODWIDTH(FEET) = 18.00
FULL HALF -STREET VELOCITY(FEET/SEC.) = 2.26
SPLIT DEPTH(FEET) = .31 SPLIT FLOODWIDTH(FEET) =
SPLIT FLOW(CFS) = 1.46 SPLIT VELOCITY(FEET/SEC.) _
STREETFLOW MODEL RESULTS:
STREET FLOWDEPTH(FEET) = .49
HALFSTREET FLOODWIDTH(FEET) = 18.00
AVERAGE FLOW VELOCITY(FEET/SEC.) =
PRODUCT OF DEPTH&VELOCITY = 1.10
STREETFLOW TRAVELTIME(MIN) = 1.11 TC(MIN)
9.04
2.26
= 44.08
8.98
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 1.925
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8156
SUBAREA AREA(ACRES) _ .23 SUBAREA RUNOFF(CFS) = .36
SUMMED AREA(ACRES) = 6.01 TOTAL RUNOFF(CFS) = 9.23
END OF SUBAREA STREETFLOW HYDRAULICS:
DEPTH(FEET) = .49 HALFSTREET FLOODWIDTH(FEET) = 18.00
FLOW VELOCITY(FEET/SEC.) = 2.26 DEPTH*VELOCITY = 1.10
1.58
FLOW PROCESS FROM NODE 905.00 TO NODE 906.00 IS CODE = 51
» » >COMPUTE TRAPEZOIDAL CHANNEL FLOW« « <
» »>TRAVELTIME THRU SUBAREA« « <
UPSTREAM NODE ELEVATION = 51.71
DOWNSTREAM NODE ELEVATION = 45.08
CHANNEL LENGTH THRU SUBAREA(FEET) = 1100.00
CHANNEL SLOPE = .0060
CHANNEL BASE(FEET) = 20.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = .025 MAXIMUM DEPTH(FEET) = 2.00
CHANNEL FLOW THRU SUBAREA(CFS) = 9.23
FLOW VELOCITY(FEET/SEC) = 1.79 FLOW DEPTH(FEET) = .25
•
•
•
TRAVEL TIME(MIN.) = 10.26 TC(MIN.) = 54.35
FLOW PROCESS FROM NODE 906.00 TO NODE 906.00 IS CODE = 8
» » >ADDITION OF SUBAREA TO MAINLINE PEAK FLOW« «<
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 1.698
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8066
SUBAREA AREA(ACRES) = 6.41 SUBAREA RUNOFF(CFS) = 8.78
TOTAL AREA(ACRES) = 12.42 TOTAL RUNOFF(CFS) = 18.00
TC(MIN) = 54.35
FLOW PROCESS FROM NODE 906.00 TO NODE 1104.00 IS CODE = 1
» » >DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE«« <
TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:
TIME OF CONCENTRATION(MIN.) = 54.35
RAINFALL INTENSITY(INCH/HR) = 1.70
TOTAL STREAM AREA(ACRES) = 12.42
PEAK FLOW RATE(CFS) AT CONFLUENCE = 18.00
FLOW PROCESS FROM NODE 1401.00 TO NODE 1402.00 IS CODE = 21
» » >RATIONAL METHOD INITIAL SUBAREA ANALYSIS « « <
ASSUMED INITIAL SUBAREA UNIFORM
DEVELOPMENT IS SINGLE FAMILY (1/4 ACRE)
TC = K*[(LENGTH**3)/(ELEVATION CHANGE)]**.2
INITIAL SUBAREA FLOW -LENGTH = 970.00
UPSTREAM ELEVATION = 56.40
DOWNSTREAM ELEVATION = 49.81
ELEVATION DIFFERENCE = 6.59
TC = .393*(( 970.00**3)/( 6.59)]**.2 = 16.682
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.449
SOIL CLASSIFICATION IS "D"
SINGLE-FAMILY(1/4 ACRE LOT) RUNOFF COEFFICIENT = .8486
SUBAREA RUNOFF(CFS) = 10.01
TOTAL AREA(ACRES) = 3.42 TOTAL RUNOFF(CFS)
10.01
FLOW PROCESS FROM NODE 1402.00 TO NODE 1403.00 IS CODE = 6
» » >COMPUTE STREETFLOW TRAVELTIME THRU SUBAREA« «<
UPSTREAM ELEVATION = 49.81 DOWNSTREAM ELEVATION = 48.12
STREET LENGTH(FEET) = 350.00 CURB HEIGHT(INCHES) = 6.
STREET HALFWIDTH(FEET) = 18.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK = 9.00
INTERIOR STREET CROSSFALL(DECIMAL) = .020
OUTSIDE STREET CROSSFALL(DECIMAL) = .020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 2
**TRAVELTIME COMPUTED USING MEAN FLOW(CFS) = 14.54
STREETFLOW MODEL RESULTS:
STREET FLOWDEPTH(FEET) = .48
HALFSTREET FLOODWIDTH(FEET) = 17.74
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.23
PRODUCT OF DEPTH&VELOCITY = 1.07
STREETFLOW TRAVELTIME(MIN) = 2.62 TC(MIN) = 19.30