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2
REPORT ON HYDROGRAPH CALCULATIONS
FOR
' 3 TEMPORARY STORM WATER RETENTION AREA
AT
EMPIRE CENTER PROJECT
PARCELS 4 & 5 OF PARCEL MAP 12195
(EAST SIDE OF SIERRA AVENUE, 800' NORTH OF JURUPA AVENUE)
FOR
ALEXANDER HAAGEN COMPANY
Q R,OF ESS10
— 0 c C - a• $7.
September 14, 1992 Lu
leS
CI VIV '. ..
OF CAL
J.N.: 4013 -066
File: 4013HRA.PFS
13821 Newport Avenue, Suite 200
Tustin, California 92680 -7803
Tel 714/544 -3404
Fax 714/544 -3155
TEMPORARY STORM WATER RETENTION AREA REPORT
TABLE OF CONTENTS
Section I - Purpose and Summary of Report
Section II - Hydrology Calculations
Section III - Hydrograph Calculations
Appendix A - Retention Area Plan & Hydrology Plan
(In Slip Jacket)
MEr
TEMPORARY STORM WATER RETENTION AREA REPORT
SECTION I - PURPOSE AND SUMMARY OF REPORT
The purpose of this report is to present the hydrology and
hydrograph calculations which establish the approximate times
to fill the Temporary Storm Water Retention Area on Parcels 4
& 5 of Parcel Map 12195 at the Empire Center Project. The
retention area is the existing low point sump on the east
side of Sierra Avenue about 800' north of Jurupa Avenue.
The sump is created by the flow line elevation of the
driveway at Station 18 +06 to the west and the over -flow
elevation of 47.5 at a farm road 2600' to the east. The
volume of available storage before over - flowing to the west
or to the east is estimated to be about 65 Acre -Feet. Refer
to the drawing folded and placed in the slip jacket of this
report for the plan of the retention area.
As of September 14, 1992, this sump area does not have a
drainage pipe system to draw -off storm water to maintain a
water surface elevation at or below elevation 47.5. The
natural fall is to the west and prior to the above date,
three (3) 24" CMP drain pipes were in operation to convey
flows under Sierra Avenue from east to west. During the
summer of 1992 these three pipes were sealed to allow the
widening of Sierra Avenue as part of the Phase I
Infrastructure Improvements for the Empire Center Project.
No provisions were installed during street widening to
compensate for the discontinued use of the three pipes.
A 108" RCP drain pipe is installed parallel to Sierra Avenue
with an inlet structure at the low point of the sump area to
receive inflow and eliminate the sump condition, however, the
108" pipe is temporarily sealed at it's outlet until the 14'w
by 9'h Jurupa Box Culvert is constructed, complete and
operational which is schedule to be around December 1992.
Until such time, the City of Fontana has plans to maintain
the water surface elevation of the temporary retention area
by means of pumps by using city work crews.
The following page is a summary of the hours to fill the 65
acre -feet by storm frequency. A Q10 is a 10 year storm which
has a 10% chance of occurrence in a particular year, a Q25
has a 4% chance of occurrence, a Q50 has a 4% chance of
occurrence, and a Q100 has a 1% chance of occurrence.
Emir
nor
TEMPORARY STORM WATER RETENTION AREA REPORT
SUMMARY OF TIME TO FILL
Storm Hours to
Frequency Fill
Q10 12.5
Q25 10.0
Q50 8.5
Q100 6.5
The Hydrology Calculations are in Section II of this report
with a Hydrology Plan on a portion of the plan that is folded
and placed in the slip jacket in Appendix A of this report.
The hydrology was run to establish times of concentration
values to be used with the Hydrograph Calculations. The
hydrology accounted for the recently completed 85 acre Palm
Court Shopping Center to the north and the 245 acre Jurupa
Mountain area to the south. There are calculations for 10,
25, 50 and 100 year storm events.
The Hydrograph Calculations are in Section III of this report
The calculations are results of 24 hour storm event hydro -
graphs based upon San Bernardino County Hydrology Manual
methods.
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mop ,
TEMPORARY STORM WATER RETENTION AREA REPORT
SECTION II - HYDROLOGY CALCULATIONS
10 Year Storm
25 Year Storm
50 Year Storm
100 Year Storm
AWSI
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Emir
our
San Bernardino County Rational Hydrology Program
(Hydrology Manual Date - August 1986)
CIVILCADD /CIVILDESIGN Engineering Software, (c) 1990 Version 2.3
Rational Hydrology Study Date: 8/27/92
E1! `+ i.-
* * * * * * * ** Hydrology Study Control Information * * * * * * * * **
Rational hydrology study storm event year is 10.0
Computed rainfall intensity:
Storm year = 10.00 1 hour rainfall p = 0.920(In.)
Slope used for rainfall intensity curve b = 0.6000
Soil antecedent moisture condition (AMC) = 2
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 1.000 to Point /Station 2.000
* * ** INITIAL AREA EVALUATION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Initial subarea data:
Initial area flow distance = 500.000(Ft.)
Top (of initial area) elevation = 1105.000(Ft.)
Bottom (of initial area) elevation = 1100.000(Ft.)
Difference in elevation = 5.000(Ft.)
Slope = 0.01000 s( %)= 1.00
TC = k(0.304) *[(length ^3) /(elevation change)]A0.2
Initial area time of concentration = 9.172 min.
Rainfall intensity = 2.839(In /Hr) for a 10.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.877
Subarea runoff = 24.893(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 0.100
Initial area Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 2.000 to Point /Station 3.000
* * ** PIPEFLOW TRAVEL TIME (Program estimated size) * * **
Upstream point /station elevation = 1095.00(Ft.)
Downstream point /station elevation = 1085.00(Ft.)
Pipe length = 800.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 24.893(CFS)
Nearest computed pipe diameter = 24.00(In.)
Calculated individual pipe flow = 24.893(CFS)
Normal flow depth in pipe = 19.34(In.)
Flow top width inside pipe = 18.99(In.)
Critical Depth = 21.09(In.)
Pipe flow velocity = 9.18(Ft /s)
Travel time through pipe = 1.45 min.
Time of concentration (TC) = 10.62 min.
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 2.000 to Point /Station 3.000
* * ** SUBAREA FLOW ADDITION * * **
CRCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Time of concentration = 10.62 min.
Rainfall intensity = 2.599(In /Hr) for a 10.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.875
Subarea runoff = 70.594(CFS) for 32.000(Ac.)
Total runoff = 95.486(CFS) Total area = 42.00(Ac.)
Area averaged Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 3.000 to Point /Station 4.000
* * ** PIPEFLOW TRAVEL TIME (Program estimated size) * * **
Upstream point /station elevation = 1085.00(Ft.)
Downstream point /station elevation = 1043.00(Ft.)
Pipe length = 5800.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 95.486(CFS)
Nearest computed pipe diameter = 45.00(In.)
Calculated individual pipe flow = 95.486(CFS)
Normal flow depth in pipe = 34.27(In.)
Flow top width inside pipe = 38.36(In.)
Critical Depth = 36.00(In.)
Pipe flow velocity = 10.58(Ft /s)
Travel time through pipe = 9.14 min.
Time of concentration (TC) = 19.76 min.
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 3.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 42.000(Ac.)
Runoff from this stream = 95.486(CFS)
sor
Time of concentration = 19.76 min.
Rainfall intensity = 1.791(In /Hr)
Area averaged loss rate (Fm) = 0.0734(In /Hr)
Area averaged Pervious ratio (Ap) = 0.1000
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 5.000 to Point /Station 6.000
* * ** INITIAL AREA EVALUATION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Initial subarea data:
Initial area flow distance = 800.000(Ft.)
Tip `rof initial area) elevation = 1100.000(Ft.)
Bottom (of initial area) elevation = 1095.000(Ft.)
Difference in elevation = 5.000(Ft.)
Slope = 0.00625 s( %)= 0.63
TC = k(0.304) *[(length ^3) /(elevation change)J^0.2
Initial area time of concentration = 12.160 min.
Rainfall intensity = 2.397(In /Hr) for a 10.0 year storm
"° Effective runoff coefficient used for area (Q =KCIA) is C = 0.872
Subarea runoff = 20.915(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 0.100
Initial area Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 6.000 to Point /Station 7.000
* * ** IMPROVED CHANNEL TRAVEL TIME * * **
Upstream point elevation = 1095.00(Ft.)
Downstream point elevation = 1090.00(Ft.)
Channel length thru subarea = 1000.00(Ft.)
Channel base width = 20.000(Ft.)
` 'y` Slope or 'Z' of left channel bank = 50.000
Slope or 'Z' of right channel bank = 50.000
Manning's 'N' = 0.015
Maximum depth of channel = 0.500(Ft.)
Flow(q) thru subarea = 20.915(CFS)
Depth of flow = 0.269(Ft.)
Average velocity = 2.328(Ft/s)
Channel flow top width = 46.867(Ft.)
Flow Velocity = 2.33(Ft /s)
Travel time = 7.16 min.
Time of concentration = 19.32 min.
Critical depth = 0.258(Ft.)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 6.000 to Point /Station 7.000
* * ** SUBAREA FLOW ADDITION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Time of concentration = 19.32 min.
Rainfall intensity = 1.816(In /Hr) for a 10.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.864
Subarea runoff = 44.953(CFS) for 32.000(Ac.)
Total runoff = 65.868(CFS) Total area = 42.00(Ac.)
Area averaged Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 7.000 to Point /Station 8.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.608(Ft.)
Average velocity = 1.782(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub- Channel flow = 65.869(CFS)
flow top width = 121.591(Ft.)
velocity= 1.782(Ft/s)
area = 36.961(Sq.Ft)
• ' ' Froude number = 0.570
Upstream point elevation = 1090.000(Ft.)
Downstream point elevation = 1065.000(Ft.)
Flow length = 2900.000(Ft.)
Travel time = 27.12 min.
Time of concentration = 46.44 min.
Depth of flow = 0.608(Ft.)
Average velocity = 1.782(Ft /s)
Total irregular channel flow = 65.868(CFS)
Irregular channel normal depth above invert elev. = 0.608(Ft.)
Average velocity of channel(s) = 1.782(Ft/s)
Sub- Channel No. 1 Critical depth = 0.484(Ft.)
Critical flow top width = 96.875(Ft.)
Critical flow velocity= 2.807(Ft /s)
Critical flow area = 23.462(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 7.000 to Point /Station 8.000
* * ** SUBAREA FLOW ADDITION * * **
AGRICULTURE ROW CROPS subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 46.44 min.
Rainfall intensity = 1.073(In /Hr) for a 10.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.578
Subarea runoff = 69.142(CFS) for 161.400(Ac.)
Total runoff = 135.010(CFS) Total area = 203.40(Ac.)
Area averaged Fm value = 0.335(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.826(Ft.)
AVefFfge velocity = 1.981(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 135.011(CFS)
flow top width = 165.113(Ft.)
velocity= 1.981(Ft/s)
area = 68.155(Sq.Ft)
Froude number = 0.543
Upstream point elevation = 1065.000(Ft.)
Downstream point elevation = 1048.000(Ft.)
Flow length = 2400.000(Ft.)
Travel time = 20.19 min.
Time of concentration = 66.63 min.
Depth of flow = 0.826(Ft.)
Average velocity = 1.981(Ft /s)
Total irregular channel flow = 135.010(CFS)
Irregular channel normal depth above invert elev. = 0.826(Ft.)
Average velocity of channel(s) = 1.981(Ft /s)
Sub- Channel No. 1 Critical depth = 0.648(Ft.)
Critical flow top width = 129.688(Ft.)
Critical flow velocity= 3.211(Ft/s)
Critical flow area = 42.047(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** SUBAREA FLOW ADDITION * * **
AGRICULTURE ROW CROPS subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 66.63 min.
Rainfall intensity = 0.864(In /Hr) for a 10.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.488
Subarea runoff = 30.034(CFS) for 164.800(Ac.)
Total runoff = 165.044(CFS) Total area = 368.20(Ac.)
Area averaged Fm value = 0.366(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 2
Stream flow area = 368.200(Ac.)
Ruihof from this stream = 165.044(CFS)
Time of concentration = 66.63 min.
Rainfall intensity = 0.864(In /Hr)
.., Area averaged loss rate (Fm) = 0.3659(In /Hr)
Area averaged Pervious ratio (Ap) = 0.8973
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 9.000 to Point /Station 10.000
* * ** INITIAL AREA EVALUATION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Initial subarea data:
Initial area flow distance = 1100.000(Ft.)
Top (of initial area) elevation = 1881.000(Ft.)
Bottom (of initial area) elevation = 1500.000(Ft.)
° Difference in elevation = 381.000(Ft.)
Slope = 0.34636 s( %)= 34.64
TC = k(0.525) *[(length ^3) /(elevation change)]^0.2
Initial area time of concentration = 10.686 min.
Rainfall intensity = 2.591(In /Hr) for a 10.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.760
Subarea runoff = 19.683(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 1.000
Initial area Fm value = 0.404(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 10.000 to Point /Station 11.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.278(Ft.)
Average velocity = 5.094(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 2.00
2 100.00 0.00
3 200.00 2.00
Manning's 'N' friction factor = 0.035
Sub- Channel flow = 19.684(CFS)
flow top width = 27.799(Ft.)
velocity= 5.094(Ft /s)
area = 3.864(Sq.Ft)
Froude number = 2.408
Upstream point elevation = 1500.000(Ft.)
Downstream point elevation = 1100.000(Ft.)
Flow length = 2000.000(Ft.)
Travel time = 6.54 min.
Time of concentration = 17.23 min.
Dapt'i of flow = 0.278(Ft.)
Average velocity = 5.094(Ft /s)
Total irregular channel flow = 19.683(CFS)
Irregular channel normal depth above invert elev. = 0.278(Ft.)
Average velocity of channel(s) = 5.094(Ft /s)
Sub- Channel No. 1 Critical depth = 0.395(Ft.)
Critical flow top width = 39.453(Ft.)
Critical flow velocity= 2.529(Ft/s)
Critical flow area = 7.783(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 10.000 to Point /Station 11.000
* * ** SUBAREA FLOW ADDITION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 17.23 min.
Rainfall intensity = 1.945(In /Hr) for a 10.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.713
Subarea runoff = 77.430(CFS) for 60.000(Ac.)
Total runoff = 97.113(CFS) Total area = 70.00(Ac.)
Area averaged Fm value = 0.404(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.601(Ft.)
Average velocity = 2.692(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 97.114(CFS)
flow top width = 120.115(Ft.)
velocity= 2.692(Ft/s)
area = 36.069(Sq.Ft)
' ' Froude number = 0.866
Upstream point elevation = 1100.000(Ft.)
Downstream point elevation = 1048.000(Ft.)
Flow length = 2600.000(Ft.)
Travel time = 16.09 min.
Time of concentration = 33.32 min.
Depth of flow = 0.601(Ft.)
AVefge velocity = 2.692(Ft/s)
Total irregular channel flow = 97.113(CFS)
Irregular channel normal depth above invert elev. = 0.601(Ft.)
Average velocity of channel(s) = 2.692(Ft/s)
Sub- Channel No. 1 Critical depth = 0.566(Ft.)
Critical flow top width = 113.281(Ft.)
Critical flow velocity= 3.027(Ft /s)
' Critical flow area = 32.082(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** SUBAREA FLOW ADDITION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
- Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 33.32 min.
Rainfall intensity = 1.309(In /Hr) for a 10.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.623
Subarea runoff = 102.603(CFS) for 175.000(Ac.)
Total runoff = 199.716(CFS) Total area = 245.00(Ac.)
Area averaged Fm value = 0.404(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 3
�,. Stream flow area = 245.000(Ac.)
Runoff from this stream = 199.716(CFS)
Time of concentration = 33.32 min.
Rainfall intensity = 1.309(In /Hr)
Area averaged loss rate (Fm) = 0.4035(In /Hr)
Area averaged Pervious ratio (Ap) = 1.0000
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In /Hr)
1 95.486 19.76 1.791
2 165.044 66.63 0.864
3 199.716 33.32 1.309
Qmax(1) =
1.000 * 1.000 * 95.486) +
2.862 * 0.297 * 165.044) +
1.532 * 0.593 * 199.716) + = 417.057
Qmax(2) =
0.460 * 1.000 * 95.486) +
1.000 * 1.000 * 165.044) +
0.508 * 1.000 * 199.716) + = 310.498
Q max(3) _
0.719 * 1.000 * 95.486) +
1.894 * 0.500 * 165.044) +
1.000 * 1.000 * 199.716) + = 424.753
Total of 3 streams to confluence:
Flow rates before confluence point:
95.486 165.044 199.716
Maximum flow rates at confluence using above data:
417.057 310.498 424.753
Area of streams before confluence:
42.000 368.200 245.000
Effective area values after confluence:
296.477 655.200 471.144
Results of confluence:
Total flow rate = 424.753(CFS)
Time of concentration = 33.324 min.
Effective stream area after confluence = 471.144(Ac.)
Study area average Pervious fraction(Ap) = 0.885
Study area average soil loss rate(Fm) = 0.361(In /Hr)
Study area total (this main stream) = 655.20(Ac.)
End of computations, total study area = 655.20 (Ac.)
The following figures may
be used for a unit hydrograph study of the same area.
Note: These figures do not consider reduced effective area
effects caused by confluences in the rational equation.
Area averaged pervious area fraction(Ap) = 0.885
Area averaged SCS curve number = 75.2
4
Am
San Bernardino County Rational Hydrology Program
(Hydrology Manual Date - August 1986)
CIVILCADD /CIVILDESIGN Engineering Software, (c) 1990 Version 2.3
s " Rational Hydrology Study Date: 8/27/92
* * * * * * * ** Hydrology Study Control Information * * * * * * * * **
Rational hydrology study storm event year is 25.0
10 Year storm 1 hour rainfall = 0.920(In.)
100 Year storm 1 hour rainfall = 1.350(In.)
Computed rainfall intensity:
Storm year = 25.00 1 hour rainfall p = 1.091(In.)
Slope used for rainfall intensity curve b = 0.6000
Soil antecedent moisture condition (AMC) = 2
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 1.000 to Point /Station 2.000
* * ** INITIAL AREA EVALUATION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Initial subarea data:
Initial area flow distance = 500.000(Ft.)
Top (of initial area) elevation = 1105.000(Ft.)
Bottom (of initial area) elevation = 1100.000(Ft.)
Difference in elevation = 5.000(Ft.)
Slope = 0.01000 s( %)= 1.00
TC = k(0.304) *[(length ^3) /(elevation change)]^0.2
Initial area time of concentration = 9.172 min.
Rainfall intensity = 3.367(In /Hr) for a 25.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.880
Subarea runoff = 29.645(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 0.100
Initial area Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 2.000 to Point /Station 3.000
* * ** PIPEFLOW TRAVEL TIME (Program estimated size) * * **
Upstream point /station elevation = 1095.00(Ft.)
Downstream point /station elevation = 1085.00(Ft.)
Pipe length = 800.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 29.645(CFS)
Nearest computed pipe diameter = 27.00(In.)
Calculated individual pipe flow = 29.645(CFS)
Normal flow depth in pipe = 19.22(In.)
Flow top width inside pipe = 24.46(In.)
Critical Depth = 22.63(In.)
Pipe flow velocity = 9.79(Ft /s)
Travel time through pipe = 1.36 min.
Time of concentration (TC) = 10.53 min.
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 2.000 to Point /Station 3.000
* * ** SUBAREA FLOW ADDITION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Time of concentration = 10.53 min.
Rainfall intensity = 3.099(In /Hr) for a 25.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.879
Subarea runoff = 84.714(CFS) for 32.000(Ac.)
Total runoff = 114.360(CFS) Total area = 42.00(Ac.)
Area averaged Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 3.000 to Point /Station 4.000
* * ** PIPEFLOW TRAVEL TIME (Program estimated size) * * **
Upstream point /station elevation = 1085.00(Ft.)
Downstream point /station elevation = 1043.00(Ft.)
Pipe length = 5800.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 114.360(CFS)
Nearest computed pipe diameter = 48.00(In.)
Calculated individual pipe flow = 114.360(CFS)
Normal flow depth in pipe = 36.84(In.)
Flow top width inside pipe = 40.55(In.)
Critical Depth = 38.74(In.)
Pipe flow velocity = 11.06(Ft /s)
Travel time through pipe = 8.74 min.
Time of concentration (TC) = 19.28 min.
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 3.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 42.000(Ac.)
Runoff from this stream = 114.360(CFS)
Time of concentration = 19.28 min.
Rainfall intensity = 2.156(In /Hr)
Area averaged loss rate (Fm) = 0.0734(In /Hr)
Area averaged Pervious ratio (Ap) = 0.1000
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 5.000 to Point /Station 6.000
* * ** INITIAL AREA EVALUATION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Initial subarea data:
Initial area flow distance = 800.000(Ft.)
Top (of initial area) elevation = 1100.000(Ft.)
Bottom (of initial area) elevation = 1095.000(Ft.)
Difference in elevation = 5.000(Ft.)
Slope = 0.00625 s( %)= 0.63
TC = k(0.304) *[(length ^3) /(elevation change))'0.2
Initial area time of concentration = 12.160 min.
Rainfall intensity = 2.843(In /Hr) for a 25.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.877
Subarea runoff = 24.928(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 0.100
Initial area Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 6.000 to Point /Station 7.000
* * ** IMPROVED CHANNEL TRAVEL TIME * * **
Upstream point elevation = 1095.00(Ft.)
Downstream point elevation = 1090.00(Ft.)
Channel length thru subarea = 1000.00(Ft.)
Channel base width = 20.000(Ft.)
Scope or 'Z' of left channel bank = 50.000
Slope or 'Z' of right channel bank = 50.000
Manning's 'N' = 0.015
Maximum depth of channel = 0.500(Ft.)
Flow(q) thru subarea = 24.928(CFS)
Depth of flow = 0.294(Ft.)
Average velocity = 2.446(Ft/s)
Channel flow top width = 49.377(Ft.)
Flow Velocity = 2.45(Ft /s)
Travel time = 6.81 min.
Time of concentration = 18.97 min.
Critical depth = 0.285(Ft.)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 6.000 to Point /Station 7.000
* * ** SUBAREA FLOW ADDITION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Time of concentration = 18.97 min.
Rainfall intensity = 2.177(In /Hr) for a 25.0 year storm
Effective runoff coefficient used for area,(total area with modified
4 rational method)(Q =KCIA) is C = 0.870
Subarea runoff = 54.592(CFS) for 32.000(Ac.)
Total runoff = 79.519(CFS) Total area = 42.00(Ac.)
Area averaged Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 7.000 to Point /Station 8.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.652(Ft.)
Average velocity = 1.868(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 79.520(CFS)
flow top width = 130.489(Ft.)
velocity= 1.868(Ft /s)
area = 42.569(Sq.Ft)
Froude number = 0.576
Upstream point elevation = 1090.000(Ft.)
Downstream point elevation = 1065.000(Ft.)
Flow length = 2900.000(Ft.)
Travel time = 25.87 min'.
Time of concentration = 44.85 min.
Depth of flow = 0.652(Ft.)
Average velocity = 1.868(Ft /s)
Total irregular channel flow = 79.519(CFS)
Irregular channel normal depth above invert elev. = 0.652(Ft.)
Average velocity of channel(s) = 1.868(Ft /s)
Sub - Channel No. 1 Critical depth = 0.523(Ft.)
Critical flow top width = 104.688(Ft.)
Critical flow velocity= 2.902(Ft /s)
Critical flow area = 27.399(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 7.000 to Point /Station 8.000
* * ** SUBAREA FLOW ADDITION * * **
AGRICULTURE ROW CROPS subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 44.85 min.
Rainfall intensity = 1.299(In /Hr) for a 25.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.634
Subarea runoff = 96.947(CFS) for 161.400(Ac.)
Total runoff = 176.466(CFS) Total area = 203.40(Ac.)
Area averaged Fm value = 0.335(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
.-r s• -
Depth of flow = 0.913(Ft.)
Average velocity = 2.118(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 176.466(CFS)
flow top width = 182.553(Ft.)
velocity= 2.118(Ft /s)
area = 83.314(Sq.Ft)
' Froude number = 0.553
Upstream point elevation = 1065.000(Ft.)
Downstream point elevation = 1048.000(Ft.)
Flow length = 2400.000(Ft.)
Travel time = 18.89 min.
Time of concentration = 63.73 min.
Depth of flow = 0.913(Ft.)
Average velocity = 2.118(Ft /s)
Total irregular channel flow = 176.466(CFS)
Irregular channel normal depth above invert elev. = 0.913(Ft.)
Average velocity of channel(s) = 2.118(Ft /s)
Sub - Channel No. 1 Critical depth = 0.719(Ft.)
Critical flow top width = 143.750(Ft.)
Critical flow velocity= 3.416(Ft /s)
Critical flow area = 51.660(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** SUBAREA FLOW ADDITION * * **
AGRICULTURE ROW CROPS subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 63.73 min.
Rainfall intensity = 1.052(In /Hr) for a 25.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.561
Subarea runoff = 51.011(CFS) for 164.800(Ac.)
0 Total runoff = 227.477(CFS) Total area = 368.20(Ac.)
Area averaged Fm value = 0.366(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Arong Main Stream number: 1 in normal stream number 2
Stream flow area = 368.200(Ac.)
Runoff from this stream = 227.477(CFS)
Time of concentration = 63.73 min.
Rainfall intensity = 1.052(In /Hr)
Area averaged loss rate (Fm) = 0.3659(In /Hr)
Area averaged Pervious ratio (Ap) = 0.8973
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 9.000 to Point /Station 10.000
* * ** INITIAL AREA EVALUATION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
�• Initial subarea data:
Initial area flow distance = 1100.000(Ft.)
Top (of initial area) elevation = 1881.000(Ft.)
Bottom (of initial area) elevation = 1500.000(Ft.)
Difference in elevation = 381.000(Ft.)
Slope = 0.34636 s( %)= 34.64
TC = k(0.525) *[(length ^3) /(elevation change)]^0.2
Initial area time of concentration = 10.686 min.
Rainfall intensity = 3.072(In /Hr) for a 25.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.782
Subarea runoff = 24.020(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 1.000
Initial area Fm value = 0.404(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 10.000 to Point /Station 11.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
0
Depth of flow = 0.300(Ft.)
Average velocity = 5.354(Ft/s)
0 * * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
W Point number 'X' coordinate 'Y' coordinate
1 0.00 2.00
2 100.00 0.00
3 200.00 2.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 24.020(CFS)
' ' flow top width = 29.954(Ft.)
velocity= 5.354(Ft/s)
area = 4.486(Sq.Ft)
Froude number = 2.438
Upstream point elevation = 1500.000(Ft.)
W Downstream point elevation = 1100.000(Ft.)
Flow length = 2000.000(Ft.)
•- Ttai el time = 6.23 min.
Time of concentration = 16.91 min.
Depth of flow = 0.300(Ft.)
Average velocity = 5.354(Ft/s)
Total irregular channel flow = 24.020(CFS)
Irregular channel normal depth above invert elev. = 0.300(Ft.)
Average velocity of channel(s) = 5.354(Ft/s)
Sub- Channel No. 1 Critical depth = 0.428(Ft.)
Critical flow top width = 42.773(Ft.)
Critical flow velocity= 2.626(Ft/s)
' Critical flow area = 9.148(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 10.000 to Point /Station 11.000
* * ** SUBAREA FLOW ADDITION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 16.91 min.
Rainfall intensity = 2.333(In /Hr) for a 25.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.744
Subarea runoff = 97.516(CFS) for 60.000(Ac.)
Total runoff = 121.536(CFS) Total area = 70.00(Ac.)
Area averaged Fm value = 0.404(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.653(Ft.)
Average velocity = 2.848(Ft/s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
r
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 121.537(CFS)
flow top width = 130.657(Ft.)
' ' velocity= 2.848(Ft/s)
area = 42.678(Sq.Ft)
Froude number = 0.878
Upstream point elevation = 1100.000(Ft.)
Downstream point elevation = 1048.000(Ft.)
Flow length = 2600.000(Ft.)
Travel time = 15.22 min.
Time f concentration = 32.13 min.
Depth of flow = 0.653(Ft.)
Average velocity = 2.848(Ft/s)
Total irregular channel flow = 121.536(CFS)
Irregular channel normal depth above invert elev. = 0.653(Ft.)
Average velocity of channel(s) = 2.848(Ft/s)
Sub - Channel No. 1 Critical depth = 0.621(Ft.)
' ' ' Critical flow top width = 124.219(Ft.)
Critical flow velocity= 3.151(Ft /s)
Critical flow area = 38.576(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** SUBAREA FLOW ADDITION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 32.13 min.
Rainfall intensity = 1.587(In/Hr) for a 25.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.671
Subarea runoff = 139.463(CFS) for 175.000(Ac.)
Total runoff = 260.999(CFS) Total area = 245.00(Ac.)
Area averaged Fm value = 0.404(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 3
Stream flow area = 245.000(Ac.)
Runoff from this stream = 260.999(CFS)
Time of concentration = 32.13 min.
Rainfall intensity = 1.587(In /Hr)
Area averaged loss rate (Fm) = 0.4035(In /Hr)
Area averaged Pervious ratio (Ap) = 1.0000
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In /Hr)
1 114.360 19.28 2.156
2 227.477 63.73 1.052
3 260.999 32.13 1.587
Qmax(1) =
' 1.000 * 1.000 * 114.360) +
2.608 * 0.302 * 227.477) +
1.481 * 0.600 * 260.999) + = 525.751
a Qmax(2) =
0.470 * 1.000 * 114.360) +
1.000 * 1.000 * 227.477) +
0.548 * 1.000 * 260.999) + = 424.282
Qmax(3) =
0.727 * 1.000 * 114.360) +
1.779 * 0.504 * 227.477) +
1.000 * 1.000 * 260.999) + = 548.137
Total of 3 streams to confluence:
Flow rates before confluence point:
114.360 227.477 260.999
Maximum flow rates at confluence using above data:
525.751 424.282 548.137
Area of streams before confluence:
42.000 368.200 245.000
Effective area values after confluence:
300.385 655.200 472.615
Results of confluence:
Total flow rate = 548.137(CFS)
Time of concentration = 32.128 min.
Effective stream area after confluence = 472.615(Ac.)
a Study area average Pervious fraction(Ap) = 0.885
Study area average soil loss rate(Fm) = 0.361(In /Hr)
Study area total (this main stream) = 655.20(Ac.)
End of computations, total study area = 655.20 (Ac.)
The following figures may
be used for a unit hydrograph study of the same area.
Note: These figures do not consider reduced effective area
- effects caused by confluences in the rational equation.
Area averaged pervious area fraction(Ap) = 0.885
Area averaged SCS curve number = 75.2
a
San Bernardino County Rational Hydrology Program
(Hydrology Manual Date - August 1986)
CIVILCADD /CIVILDESIGN Engineering Software, (c) 1990 Version 2.3
Rational Hydrology Study Date: 8/27/92
* * * * * * * ** Hydrology Study Control Information * * * * * * * * **
Rational hydrology study storm event year is 50.0
10 Year storm 1 hour rainfall = 0.920(In.)
100 Year storm 1 hour rainfall = 1.350(In.)
Computed rainfall intensity:
Storm year = 50.00 1 hour rainfall p = 1.221(In.)
Slope used for rainfall intensity curve b = 0.6000
Soil antecedent moisture condition (AMC) = 2
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 1.000 to Point /Station 2.000
* * ** INITIAL AREA EVALUATION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Initial subarea data:
Initial area flow distance = 500.000(Ft.)
Top (of initial area) elevation = 1105.000(Ft.)
Bottom (of initial area) elevation = 1100.000(Ft.)
Difference in elevation = 5.000(Ft.)
Scope = 0.01000 s( %)= 1.00
TC = k(0.304) *[(length ^3) /(elevation change)]'0.2
Initial area time of concentration = 9.172 min.
Rainfall intensity = 3.767(In /Hr) for a 50.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.882
Subarea runoff = 33.241(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 0.100
Initial area Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 2.000 to Point /Station 3.000
* * ** PIPEFLOW TRAVEL TIME (Program estimated size) * * **
Upstream point /station elevation = 1095.00(Ft.)
Downstream point /station elevation = 1085.00(Ft.)
Pipe length = 800.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 33.241(CFS)
Nearest computed pipe diameter = 27.00(In.)
Calculated individual pipe flow = 33.241(CFS)
Normal flow depth in pipe = 21.23(In.)
Flow top width inside pipe = 22.13(In.)
Critical Depth = 23.69(In.)
Pipe flow velocity = 9.92(Ft /s)
Travel time through pipe = 1.34 min.
Time of concentration (TC) = 10.52 min.
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 2.000 to Point /Station 3.000
*`if*SUBAREA FLOW ADDITION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Time of concentration = 10.52 min.
Rainfall intensity = 3.470(In /Hr) for a 50.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.881
Subarea runoff = 95.151(CFS) for 32.000(Ac.)
Total runoff = 128.392(CFS) Total area = 42.00(Ac.)
Area averaged Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 3.000 to Point /Station 4.000
* * ** PIPEFLOW TRAVEL TIME (Program estimated size) * * **
Upstream point /station elevation = 1085.00(Ft.)
Downstream point /station elevation = 1043.00(Ft.)
Pipe length = 5800.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 128.392(CFS)
Nearest computed pipe diameter = 48.00(In.)
Calculated individual pipe flow = 128.392(CFS)
Normal flow depth in pipe = 42.00(In.)
Flow top width inside pipe = 31.75(In.)
Critical Depth = 40.72(In.)
Pipe flow velocity = 11.02(Ft /s)
Travel time through pipe = 8.78 min.
Time of concentration (TC) = 19.29 min.
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 3.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 42.000(Ac.)
Runoff from this stream = 128.392(CFS)
Time of concentration = 19.29 min.
Rainfall intensity = 2.411(In /Hr)
Area averaged loss rate (Fm) = 0.0734(In /Hr)
Area averaged Pervious ratio (Ap) = 0.1000
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 5.000 to Point /Station 6.000
* * ** INITIAL AREA EVALUATION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Initial subarea data:
Initial area flow distance = 800.000(Ft.)
Top (of initial area) elevation = 1100.000(Ft.)
Bottom (of initial area) elevation = 1095.000(Ft.)
Difference in elevation = 5.000(Ft.)
Slope = 0.00625 s( %)= 0.63
TC = k(0.304) *[(length ^3) /(elevation change)] ^0.2
Initial area time of concentration = 12.160 min.
Rainfall intensity = 3.180(In /Hr) for a 50.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.879
Subarea runoff = 27.964(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 0.100
Initial area Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 6.000 to Point /Station 7.000
* * ** IMPROVED CHANNEL TRAVEL TIME * * **
Upstream point elevation = 1095.00(Ft.)
Downstream point elevation = 1090.00(Ft.)
Channel length thru subarea = 1000.00(Ft.)
Channel base width = 20.000(Ft.)
Slope or 'Z' of left channel bank = 50.000
Slope or 'Z' of right channel bank = 50.000
Manning's 'N' = 0.015
Maximum depth of channel = 0.500(Ft.)
Flow(q) thru subarea = 27.964(CFS)
Depth of flow = 0.311(Ft.)
Average velocity = 2.526(Ft/s)
Channel flow top width = 51.130(Ft.)
Flow Velocity = 2.53(Ft /s)
Travel time = 6.60 min.
Time of concentration = 18.76 min.
Critical depth = 0.305(Ft.)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 6.000 to Point /Station 7.000
* * ** SUBAREA FLOW ADDITION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.073(In /Hr)
Time of concentration = 18.76 min.
Rainfall intensity = 2.452(In /Hr) for a 50.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.873
Subarea runoff = 61.949(CFS) for 32.000(Ac.)
Total runoff = 89.913(CFS) Total area = 42.00(Ac.)
- Area averaged Fm value = 0.073(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 7.000 to Point/Station 8.000
** *IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.683(Ft.)
Average velocity = 1.926(Ft/s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 89.913(CFS)
flow top width = 136.641(Ft.)
velocity= 1.926(Ft/s)
area = 46.677(Sq.Ft)
Froude number = 0.581
Upstream point elevation = 1090.000(Ft.)
Downstream point elevation = 1065.000(Ft.)
Flow length = 2900.000(Ft.)
Travel time = 25.09 min.
Time of concentration = 43.85 min.
Depth of flow = 0.683(Ft.)
Average velocity = 1.926(Ft /s)
Total irregular channel flow = 89.913(CFS)
�« Irregular channel normal depth above invert elev. = 0.683(Ft.)
Average velocity of channel(s) = 1.926(Ft/s)
Sub - Channel No. 1 Critical depth = 0.551(Ft.)
Critical flow top width = 110.156(Ft.)
Critical flow velocity= 2.964(Ft /s)
Critical flow area = 30.336(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 7.000 to Point /Station 8.000
* * ** SUBAREA FLOW ADDITION * * **
AGRICULTURE ROW CROPS subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 43.85 min.
Rainfall intensity = 1.473(In /Hr) for a 50.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.665
Subarea runoff = 118.385(CFS) for 161.400(Ac.)
Total runoff = 208.298(CFS) Total area = 203.40(Ac.)
Area averaged Fm value = 0.335(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.971(Ft.)
Average velocity = 2.208(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 208.298(CFS)
flow top width = 194.267(Ft.)
velocity= 2.208(Ft /s)
area = 94.349(Sq.Ft)
Froude number = 0.558
Upstream point elevation = 1065.000(Ft.)
Downstream point elevation = 1048.000(Ft.)
Flow length = 2400.000(Ft.)
Travel time = 18.12 min.
Time of concentration = 61.97 min.
Depth of flow = 0.971(Ft.)
Average velocity = 2.208(Ft /s)
Total irregular channel flow = 208.298(CFS)
Irregular channel normal depth above invert elev. = 0.971(Ft.)
Average velocity of channel(s) = 2.208(Ft /s)
Sub- Channel No. 1 Critical depth = 0.770(Ft.)
Critical flow top width = 153.906(Ft.)
Critical flow velocity= 3.517(Ft/s)
Critical flow area = 59.218(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** SUBAREA FLOW ADDITION * * **
AGRICULTURE ROW CROPS subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 61.97 min.
Rainfall intensity = 1.197(In /Hr) for a 50.0 year storm
,fts Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.602
Subarea runoff = 67.174(CFS) for 164.800(Ac.)
Total runoff = 275.472(CFS) Total area = 368.20(Ac.)
Area averaged Fm value = 0.366(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 2
Stream flow area = 368.200(Ac.)
Runoff from this stream = 275.472(CFS)
Time of concentration = 61.97 min.
Rainfall intensity = 1.197(In /Hr)
Area averaged loss rate (Fm) = 0.3659(In /Hr)
Area averaged Pervious ratio (Ap) = 0.8973
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 9.000 to Point /Station 10.000
* * ** INITIAL AREA EVALUATION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Initial subarea data:
Initial area flow distance = 1100.000(Ft.)
Top (of initial area) elevation = 1881.000(Ft.)
Bottom (of initial area) elevation = 1500.000(Ft.)
Difference in elevation = 381.000(Ft.)
Slope = 0.34636 s( %)= 34.64
TC = k(0.525) *[(length ^3) /(elevation change)) "O.2
� - Initial area time of concentration = 10.686 min.
Rainfall intensity = 3.437(In /Hr) for a 50.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.794
Subarea runoff = 27.300(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 1.000
Initial area Fm value = 0.404(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 10.000 to Point /Station 11.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.314(Ft.)
Average velocity = 5.528(Ft/s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 2.00
2 100.00 0.00
3 200.00 2.00
Manning's 'N' friction factor = 0.035
Sub- Channel flow = 27.300(CFS)
' ' flow top width = 31.427(Ft.)
velocity= 5.528(Ft/s)
area = 4.938(Sq.Ft)
Froude number = 2.458
Upstream point elevation = 1500.000(Ft.)
Downstream point elevation = 1100.000(Ft.)
Flow length = 2000.000(Ft.)
Tradel time = 6.03 min.
Time of concentration = 16.72 min.
Depth of flow = 0.314(Ft.)
Average velocity = 5.528(Ft/s)
Total irregular channel flow = 27.300(CFS)
Irregular channel normal depth above invert elev. = 0.314(Ft.)
Average velocity of channel(s) = 5.528(Ft/s)
Sub- Channel No. 1 Critical depth = 0.449(Ft.)
Critical flow top width = 44.922(Ft.)
Critical flow velocity= 2.706(Ft /s)
Critical flow area = 10.090(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 10.000 to Point /Station 11.000
* * ** SUBAREA FLOW ADDITION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 16.72 min.
Rainfall intensity = 2.628(In /Hr) for a 50.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.762
Subarea runoff = 112.824(CFS) for 60.000(Ac.)
Total runoff = 140.124(CFS) Total area = 70.00(Ac.)
Area averaged Fm value = 0.404(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.689(Ft.)
Average velocity = 2.951(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 140.125(CFS)
flow top width = 137.820(Ft.)
' ' velocity= 2.951(Ft /s)
area = 47.486(Sq.Ft)
Froude number = 0.886
Upstream point elevation = 1100.000(Ft.)
Downstream point elevation = 1048.000(Ft.)
Flow length = 2600.000(Ft.)
Travel time = 14.68 min.
Timt'of concentration = 31.40 min.
Depth of flow = 0.689(Ft.)
Average velocity = 2.951(Ft/s)
Total irregular channel flow = 140.124(CFS)
Irregular channel normal depth above invert elev. = 0.689(Ft.)
Average velocity of channel(s) = 2.951(Ft/s)
Sub - Channel No. 1 Critical depth = 0.656(Ft.)
Critical flow top width = 131.250(Ft.)
Critical flow velocity= 3.254(Ft/s)
Critical flow area = 43.066(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** SUBAREA FLOW ADDITION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.404(In /Hr)
Time of concentration = 31.40 min.
Rainfall intensity = 1.800(In /Hr) for a 50.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.698
Subarea runoff = 167.815(CFS) for 175.000(Ac.)
Total runoff = 307.939(CFS) Total area = 245.00(Ac.)
Area averaged Fm value = 0.404(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 3
Stream flow area = 245.000(Ac.)
Runoff from this stream = 307.939(CFS)
Time of concentration = 31.40 min.
Rainfall intensity = 1.800(In /Hr)
Area averaged loss rate (Fm) = 0.4035(In /Hr)
Area averaged Pervious ratio (Ap) = 1.0000
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In /Hr)
1 128.392 19.29 2.411
2 275.472 61.97 1.197
3 307.939 31.40 1.800
Qmax(1) =
1.000 * 1.000 * 128.392) +
2.460 * 0.311 * 275.472) +
1.438 * 0.614 * 307.939) + = 611.372
Qmax(2) =
0.481 * 1.000 * 128.392) +
1.000 * 1.000 * 275.472) +
0.568 * 1.000 * 307.939) + = 512.186
Qmax(3) =
0.739 * 1.000 * 128.392) +
1.725 * 0.507 * 275.472) +
1.000 * 1.000 * 307.939) + = 643.596
Total of 3 streams to confluence:
Flow rates before confluence point:
128.392 275.472 307.939
Maximum flow rates at confluence using above data:
611.372 512.186 643.596
Area of streams before confluence:
42.000 368.200 245.000
Effective area values after confluence:
307.153 655.200 473.573
Results of confluence:
Total flow rate = 643.596(CFS)
Time of concentration = 31.400 min.
Effective stream area after confluence = 473.573(Ac.)
Study area average Pervious fraction(Ap) = 0.885
Study area average soil loss rate(Fm) = 0.361(In /Hr)
Study area total (this main stream) = 655.20(Ac.)
End of computations, total study area = 655.20 (Ac.)
The following figures may
be used for a unit hydrograph study of the same area.
Note: These figures do not consider reduced effective area
M effects caused by confluences in the rational equation.
Area averaged pervious area fraction(Ap) = 0.885
,,, Area averaged SCS curve number = 75.2
San Bernardino County Rational Hydrology Program
(Hydrology Manual Date - August 1986)
CIVILCADD /CIVILDESIGN Engineering Software, (c) 1990 Version 2.3
Rational Hydrology Study Date: 8/27/92
.....
********* Hydrology Study Control Information * * * * * * * * **
Rational hydrology study storm event year is 100.0
Computed rainfall intensity:
Storm year = 100.00 1 hour rainfall p = 1.350(In.)
Slope used for rainfall intensity curve b = 0.6000
Soil antecedent moisture condition (AMC) = 3
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 1.000 to Point /Station 2.000
* * ** INITIAL AREA EVALUATION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Adjusted SCS curve number for AMC 3 = 75.80
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.044(In /Hr)
Initial subarea data:
Initial area flow distance = 500.000(Ft.)
Top (of initial area) elevation = 1105.000(Ft.)
Bottom (of initial area) elevation = 1100.000(Ft.)
Difference in elevation = 5.000(Ft.)
Slope = 0.01000 s( %)= 1.00
TC = k(0.304) *[(length ^3) /(elevation change)1'0.2
Initial area time of concentration = 9.172 min.
Rainfall intensity = 4.166(In /Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.890
Subarea runoff = 37.101(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 0.100
Initial area Fm value = 0.044(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 2.000 to Point /Station 3.000
* * ** PIPEFLOW TRAVEL TIME (Program estimated size) * * **
Upstream point /station elevation = 1095.00(Ft.)
Downstream point /station elevation = 1085.00(Ft.)
Pipe length = 800.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 37.101(CFS)
Nearest computed pipe diameter = 30.00(In.)
Calculated individual pipe flow = 37.101(CFS)
Normal flow depth in pipe = 20.46(In.)
Flow top width inside pipe = 27.94(In.)
Critical Depth = 24.75(In.)
Pipe flow velocity = 10.40(Ft /s)
Travel time through pipe = 1.28 min.
L Time of concentration (TC) = 10.45 min.
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 2.000 to Point /Station 3.000
* * ** SUBAREA FLOW ADDITION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Adjusted SCS curve number for AMC 3 = 75.80
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.044(In /Hr)
Time of concentration = 10.45 min.
Rainfall intensity = 3.852(In /Hr) for a 100.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.890
Subarea runoff = 106.831(CFS) for 32.000(Ac.)
Total runoff = 143.932(CFS) Total area = 42.00(Ac.)
Area averaged Fm value = 0.044(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 3.000 to Point /Station 4.000
* * ** PIPEFLOW TRAVEL TIME (Program estimated size) * * **
Upstream point /station elevation = 1085.00(Ft.)
Downstream point /station elevation = 1043.00(Ft.)
Pipe length = 5800.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 143.932(CFS)
Nearest computed pipe diameter = 51.00(In.)
Calculated individual pipe flow = 143.932(CFS)
Normal flow depth in pipe = 41.91(In.)
Flow top width inside pipe = 39.04(In.)
Critical Depth = 42.59(In.)
Pipe flow velocity = 11.55(Ft /s)
'" Travel time through pipe = 8.37 min.
Time of concentration (TC) = 18.83 min.
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 3.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 1
Stream flow area = 42.000(Ac.)
Runoff from this stream = 143.932(CFS)
Time of concentration = 18.83 min.
Rainfall intensity = 2.706(In /Hr)
Area averaged loss rate (Fm) = 0.0440(In /Hr)
Area averaged Pervious ratio (Ap) = 0.1000
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 5.000 to Point /Station 6.000
* * ** INITIAL AREA EVALUATION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Adjusted SCS curve number for AMC 3 = 75.80
Pe`YvTous ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.044(In /Hr)
Initial subarea data:
Initial area flow distance = 800.000(Ft.)
Top (of initial area) elevation = 1100.000(Ft.)
Bottom (of initial area) elevation = 1095.000(Ft.)
Difference in elevation = 5.000(Ft.)
Slope = 0.00625 s( %)= 0.63
TC = k(0.304) *[(length ^3) /(elevation change)] ^0.2
Initial area time of concentration = 12.160 min.
Rainfall intensity = 3.518(In /Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.889
Subarea runoff = 31.264(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 0.100
Initial area Fm value = 0.044(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 6.000 to Point /Station 7.000
* * ** IMPROVED CHANNEL TRAVEL TIME * * **
Upstream point elevation = 1095.00(Ft.)
Downstream point elevation = 1090.00(Ft.)
Channel length thru subarea = 1000.00(Ft.)
Channel base width = 20.000(Ft.)
Slope or 'Z' of left channel bank = 50.000
Slope or 'Z' of right channel bank = 50.000
Manning's 'N' = 0.015
Maximum depth of channel = 0.500(Ft.)
Flow(q) thru subarea = 31.264(CFS)
Depth of flow = 0.329(Ft.)
Average velocity = 2.605(Ft /s)
Channel flow top width = 52.918(Ft.)
Flow Velocity = 2.60(Ft /s)
- Travel time = 6.40 min.
Time of concentration = 18.56 min.
Critical depth = 0.324(Ft.)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 6.000 to Point /Station 7.000
* * ** SUBAREA FLOW ADDITION * * **
COMMERCIAL subarea type
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 56.00
Adjusted SCS curve number for AMC 3 = 75.80
Pervious ratio(Ap) = 0.1000 Max loss rate(Fm)= 0.044(In /Hr)
Time of concentration = 18.56 min.
Rainfall intensity = 2.730(In /Hr) for a 100.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.885
Subarea runoff = 70.254(CFS) for 32.000(Ac.)
Total runoff = 101.517(CFS) Total area = 42.00(Ac.)
Area averaged Fm value = 0.044(In /Hr)
4 +- M++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 7.000 to Point /Station 8.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.715(Ft.)
Average velocity = 1.986(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 101.517(CFS)
flow top width = 143.005(Ft.)
velocity= 1.986(Ft /s)
area = 51.126(Sq.Ft)
Froude number = 0.585
Upstream point elevation = 1090.000(Ft.)
Downstream point elevation = 1065.000(Ft.)
Flow length = 2900.000(Ft.)
Travel time = 24.34 min.
Time of concentration = 42.90 min.
Depth of flow = 0.715(Ft.)
Average velocity = 1.986(Ft /s)
Total irregular channel flow = 101.517(CFS)
Irregular channel normal depth above invert elev. = 0.715(Ft.)
Average velocity of channel(s) = 1.986(Ft/s)
Sub - Channel No. 1 Critical depth = 0.578(Ft.)
Critical flow top width = 115.625(Ft.)
Critical flow velocity= 3.037(Ft /s)
Critical flow area = 33.423(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 7.000 to Point /Station 8.000
* * ** SUBAREA FLOW ADDITION * * **
AGRICULTURE ROW CROPS subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Adjusted SCS curve number for AMC 3 = 92.80
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.140(In /Hr)
Time of concentration = 42.90 min.
Rainfall intensity = 1.651(In /Hr) for a 100.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.810
Subarea runoff = 178.717(CFS) for 161.400(Ac.)
Total runoff = 280.234(CFS) Total area = 203.40(Ac.)
Area averaged Fm value = 0.120(In /Hr)
+'+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 1.070(Ft.)
Average velocity = 2.457(Ft/s)
!!Warning: Water is above left or right bank elevations
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 280.235(CFS)
flow top width = 200.000(Ft.)
velocity= 2.457(Ft/s)
area = 114.049(Sq.Ft)
Froude number = 0.573
Upstream point elevation = 1065.000(Ft.)
Downstream point elevation = 1048.000(Ft.)
Flow length = 2400.000(Ft.)
Travel time = 16.28 min.
Time of concentration = 59.18 min.
Depth of flow = 1.070(Ft.)
Average velocity = 2.457(Ft/s)
Total irregular channel flow = 280.234(CFS)
Irregular channel normal depth above invert elev. = 1.070(Ft.)
Average velocity of channel(s) = 2.457(Ft/s)
!!Warning: Water is above left or right bank elevations
Sub - Channel No. 1 Critical depth = 0.867(Ft.)
Critical flow top width = 173.438(Ft.)
Critical flow velocity= 3.726(Ft/s)
Critical flow area = 75.201(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** SUBAREA FLOW ADDITION * * **
AGRICULTURE ROW CROPS subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Adjusted SCS curve number for AMC 3 = 92.80
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.140(In /Hr)
Time of concentration = 59.18 min.
Rainfall intensity = 1.361(In /Hr) for a 100.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.797
Subarea runoff = 128.074(CFS) for 164.800(Ac.)
Total runoff = 408.308(CFS) Total area = 368.20(Ac.)
Area averaged Fm value = 0.129(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 8.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
Along Main Stream number: 1 in normal stream number 2
Stream flow area = 368.200(Ac.)
Runoff from this stream = 408.308(CFS)
Time of concentration = 59.18 min.
Rainfall intensity = 1.361(In /Hr)
Area averaged loss rate (Fm) = 0.1291(In /Hr)
Area averaged Pervious ratio (Ap) = 0.8973
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 9.000 to Point /Station 10.000
* * ** INITIAL AREA EVALUATION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Adjusted SCS curve number for AMC 3 = 92.80
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.140(In /Hr)
Initial subarea data:
Initial area flow distance = 1100.000(Ft.)
Top (of initial area) elevation = 1881.000(Ft.)
Bottom (of initial area) elevation = 1500.000(Ft.)
Difference in elevation = 381.000(Ft.)
Slope = 0.34636 s( %)= 34.64
TC = k(0.525) *[(length ^3) /(elevation change)]^0.2
Initial area time of concentration = 10.686 min.
Rainfall intensity = 3.801(In /Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q =KCIA) is C = 0.867
Subarea runoff = 32.952(CFS)
Total initial stream area = 10.000(Ac.)
Pervious area fraction = 1.000
Initial area Fm value = 0.140(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 10.000 to Point /Station 11.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.337(Ft.)
Average velocity = 5.795(Ft/s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 2.00
2 100.00 0.00
3 200.00 2.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 32.952(CFS)
flow top width = 33.725(Ft.)
velocity= 5.795(Ft/s)
area = 5.687(Sq.Ft)
Froude number = 2.487
Upstream point elevation = 1500.000(Ft.)
Downstream point elevation = 1100.000(Ft.)
Flow length = 2000.000(Ft.)
Travel time = 5.75 min.
Time of concentration = 16.44 min.
Depth of flow = 0.337(Ft.)
Average velocity = 5.795(Ft/s)
Total irregular channel flow = 32.952(CFS)
Irregular channel normal depth above invert elev. = 0.337(Ft.)
Average velocity of channel(s) = 5.795(Ft/s)
Sub - Channel No. 1 Critical depth = 0.484(Ft.)
Critical flow top width = 48.438(Ft.)
Critical flow velocity= 2.809(Ft /s)
Critical flow area = 11.731(Sq.Ft)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 10.000 to Point /Station 11.000
* * ** SUBAREA FLOW ADDITION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Adjusted SCS curve number for AMC 3 = 92.80
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.140(In /Hr)
Time of concentration = 16.44 min.
Rainfall intensity = 2.936(In /Hr) for a 100.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.857
Subarea runoff = 143.175(CFS) for 60.000(Ac.)
Total runoff = 176.127(CFS) Total area = 70.00(Ac.)
Area averaged Fm value = 0.140(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** IRREGULAR CHANNEL FLOW TRAVEL TIME * * **
Depth of flow = 0.751(Ft.)
Average velocity = 3.124(Ft /s)
* * * * * ** Irregular Channel Data * * * * * * * * * **
Information entered for subchannel number 1 :
Point number 'X' coordinate 'Y' coordinate
1 0.00 1.00
2 100.00 0.00
3 200.00 1.00
Manning's 'N' friction factor = 0.035
Sub - Channel flow = 176.127(CFS)
flow top width = 150.159(Ft.)
velocity= 3.124(Ft/s)
area = 56.370(Sq.Ft)
Froude number = 0.899
Upstream point elevation = 1100.000(Ft.)
Downstream point elevation = 1048.000(Ft.)
Flow length = 2600.000(Ft.)
Travel time = 13.87 min.
Time of concentration = 30.31 min.
Depth of flow = 0.751(Ft.)
Average velocity = 3.124(Ft /s)
Total irregular channel flow = 176.127(CFS)
Irregular channel normal depth above invert elev. = 0.751(Ft.)
Average velocity of channel(s) = 3.124(Ft /s)
Sub - Channel No. 1 Critical depth = 0.719(Ft.)
Critical flow top width = 143.750(Ft.)
Critical flow velocity= 3.409(Ft/s)
Critical flow area = 51.660(Sq.Ft)
1
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** SUBAREA FLOW ADDITION * * **
UNDEVELOPED (poor cover) subarea
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
SCS curve number for soil(AMC 2) = 78.00
Adjusted SCS curve number for AMC 3 = 92.80
Pervious ratio(Ap) = 1.0000 Max loss rate(Fm)= 0.140(In /Hr)
Time of concentration = 30.31 min.
Rainfall intensity = 2.034(In /Hr) for a 100.0 year storm
Effective runoff coefficient used for area,(total area with modified
rational method)(Q =KCIA) is C = 0.838
Subarea runoff = 241.439(CFS) for 175.000(Ac.)
Total runoff = 417.566(CFS) Total area = 245.00(Ac.)
Area averaged Fm value = 0.140(In /Hr)
+++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Process from Point /Station 11.000 to Point /Station 4.000
* * ** CONFLUENCE OF MINOR STREAMS * * **
0
Along Main Stream number: 1 in normal stream number 3
Stream flow area = 245.000(Ac.)
Runoff from this stream = 417.566(CFS)
Time of concentration = 30.31 min.
Rainfall intensity = 2.034(In /Hr)
4 Area averaged loss rate (Fm) = 0.1400(In /Hr)
Area averaged Pervious ratio (Ap) = 1.0000
Summary of stream data:
Stream Flow rate TC Rainfall Intensity
No. (CFS) (min) (In /Hr)
I- 143.932 18.83 2.706
2 408.308 59.18 1.361
3 417.566 30.31 2.034
Qmax (1) =
1.000 * 1.000 * 143.932) +
2.092 * 0.318 * 408.308) +
1.355 * 0.621 * 417.566) + = 767.122
Qmax (2) =
0.495 * 1.000 * 143.932) +
1.000 * 1.000 * 408.308) +
0.645 * 1.000 * 417.566) + = 748.797
Qmax(3) =
0.747 * 1.000 * 143.932) +
1.546 * 0.512 * 408.308) +
1.000 * 1.000 * 417.566) + = 848.386
Total of 3 streams to confluence:
Flow rates before confluence point:
143.932 408.308 417.566
Maximum flow rates at confluence using above data:
767.122 748.797 848.386
Area of streams before confluence:
42.000 368.200 245.000
Effective area values after confluence:
311.333 655.200 475.567
Results of confluence:
Total flow rate = 848.386(CFS)
Time of concentration = 30.307 min.
Effective stream area after confluence = 475.567(Ac.)
Study area average Pervious fraction(Ap) = 0.885
Study area average soil loss rate(Fm) = 0.128(In /Hr)
Study area total (this main stream) = 655.20(Ac.)
End of computations, total study area = 655.20 (Ac.)
The following figures may
be used for a unit hydrograph study of the same area.
Note: These figures do not consider reduced effective area
effects caused by confluences in the rational equation.
Area averaged pervious area fraction(Ap) = 0.885
Area averaged SCS curve number = 75.2
TEMPORARY STORM WATER RETENTION AREA REPORT
SECTION III - HYDROGRAPH CALCULATIONS
10 Year Storm
25 Year Storm
50 Year Storm
100 Year Storm
Noir
our
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
Y
sac.-
+++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 10
Antecedent Moisture Condition = 2
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 10
655.20 1 0.92
Rainfall data for year 2
655.20 6 1.63
Rainfall data for year 2
655.20 24 3.10
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 2) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 56.0 84.00 0.128 0.734 0.100 0.073
81.0 81.0 326.20 0.498 0.353 1.000 0.353
86.0 86.0 245.00 0.374 0.265 1.000 0.265
Area - averaged adjusted loss rate Fm (In /Hr)= 0.284
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC2) yield fr
8.40 0.013 56.0 56.0 7.86 0.215
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 81.0 2.35 0.604
-• 245.00 0.374 86.0 86.0 1.63 0.699
Area - averaged catchment yield fraction, Y = 0.675
Area.= averaged low loss fraction, Yb = 0.325
+++++++++++++++++++++++++++++++++++++ + + ++ + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.555 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.444 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 112.6126
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.284 (In /hr)
Average low loss rate fraction (Yb) = 0.325 (decimal)
Valley Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.340 inches
Computed peak 30- minute rainfall = 0.697 inches
Specified peak 1 -hour rainfall = 0.920 inches
Computed peak 3 -hour rainfall = 1.656 inches
Specified peak 6 -hour rainfall = 2.399 inches
Specified peak 24 -hour rainfall = 5.116 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.330 inches
30- minute factor = 0.969 Adjusted rainfall = 0.676 inches
1 -hour factor = 0.969 Adjusted rainfall = 0.892 inches
3 -hour factor = 0.996 Adjusted rainfall = 1.649 inches
6 -hour factor = 0.998 Adjusted rainfall = 2.394 inches
24 -hour factor = 0.999 Adjusted rainfall = 5.112 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
mr
1 22.815 301.303
2 73.686 671.828
3 87.568 183.326
4 93.298 75.667
5 96.397 40.928
6 98.291 25.011
7 99.408 14.759
8 100.000 7.815
Total soil rain loss = 0.74 (In.)
Total effective runoff = 1.65 (In.)
Total soil -loss volume = 40.4856 (Acre -Feet)
Total storm runoff volume = 90.2032 (Acre -Feet)
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
6 - H O U R S T O R M R u n o f f H y d r o g rap h
s „
Hydrograph in 30 Minute intervals (CFS)
Time(h +m) Volume(AF) Q(CFS) 0 100.0 200.0 300.0 400.0
0 +30 0.9267 22.43 V Q
1+ 0 3.9829 73.96 V Q
1 +30 7.8223 92.92 V Q
- 2+ 0 12.2122 106.23 V Q
2 +30 17.2157 121.09 V Q
"' 3+ 0 23.0363 140.86 V Q
3 +30 29.7448 162.34 V Q
4+ 0 38.3660 208.63 V Q
- 4 +30 51.9968 329.86 V Q
5+ 0 67.4713 374.48 V Q
. 5 +30 76.2855 213.30 Q V
6+ 0 82.6525 154.08 Q V
6 +30 86.9507 104.02 Q V
. 7+ 0 88.6451 41.00 Q V
7 +30 89.4944 20.55 Q V
's 8+ 0 89.9256 10.44 Q V
8 +30 90.1011 4.25 Q V
9+ 0 90.1780 1.86 Q V
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
+++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 10
Antecedent Moisture Condition = 2
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 10
655.20 1 0.92
Rainfall data for year 2
655.20 6 1.63
Rainfall data for year 2
655.20 24 3.10
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 2) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 56.0 84.00 0.128 0.734 0.100 0.073
81.0 81.0 326.20 0.498 0.353 1.000 0.353
86.0 86.0 245.00 0.374 0.265 1.000 0.265
Area - averaged adjusted loss rate Fm (In /Hr)= 0.284
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC2) yield fr
8.40 0.013 56.0 56.0 7.86 0.215
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 81.0 2.35 0.604
245.00 0.374 86.0 86.0 1.63 0.699
Area - averaged catchment yield fraction, Y = 0.675
Area ,averaged low loss fraction, Yb = 0.325
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.555 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.444 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 112.6126
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.284 (In /hr)
Average low loss rate fraction (Yb) = 0.325 (decimal)
Valley Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.340 inches
Computed peak 30- minute rainfall = 0.697 inches
Specified peak 1 -hour rainfall = 0.920 inches
Computed peak 3 -hour rainfall = 1.656 inches
Specified peak 6 -hour rainfall = 2.399 inches
Specified peak 24 -hour rainfall = 5.116 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.330 inches
30- minute factor = 0.969 Adjusted rainfall = 0.676 inches
1 -hour factor = 0.969 Adjusted rainfall = 0.892 inches
3 -hour factor = 0.996 Adjusted rainfall = 1.649 inches
6 -hour factor = 0.998 Adjusted rainfall = 2.394 inches
24 -hour factor = 0.999 Adjusted rainfall = 5.112 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 22.815 301.303
2 73.686 671.828
3 87.568 183.326
4 93.298 75.667
5 96.397 40.928
6 98.291 25.011
7 99.408 14.759
8 100.000 7.815
Total soil rain loss = 1.10 (In.)
Total effective runoff = 2.40 (In.)
- Total soil -loss volume = 60.0533 (Acre -Feet)
Total storm runoff volume = 130.8978 (Acre -Feet)
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
12 - H O U R S T O R M
- R u n o f f H y d r o g r a p h
- y .-
Hydrograph in 30 Minute intervals (CFS)
- Time(h +m) Volume(AF) Q(CFS) 0 100.0 200.0 300.0 400.0
0 +30 0.6793 16.44 VQ
1+ 0 2.8940 53.60 V Q
1 +30 5.5912 65.27 V Q
- 2+ 0 8.5484 71.56 V Q
2 +30 11.7027 76.33 V Q
'" 3+ 0 15.0340 80.62 V Q
3 +30 18.5374 84.78 V Q
4+ 0 22.2186 89.09 V Q
4 +30 26.0716 93.24 V Q
5+ 0 30.1124 97.79 Q
5 +30 34.4154 104.13 Q
6+ 0 39.0564 112.31 Q
- 6 +30 44.1964 124.39 QV
• 7+ 0 50.0826 142.45 QV
7 +30 56.8141 162.90 QV
., 8+ 0 65.4354 208.63 VQ
8 +30 79.0662 329.86 V Q
9+ 0 94.5406 374.48 V Q
9 +30 103.3549 213.30 Q V
10+ 0 109.7218 154.08 Q V
10 +30 114.8964 125.22 Q v
11+ 0 119.3439 107.63 Q V
11 +30 123.2481 94.48 Q V
12+ 0 126.7288 84.23 Q V
12 +30 129.2198 60.28 Q V
- 13+ 0 130.0857 20.95 Q V
13 +30 130.4947 9.90 Q V
'"' 14+ 0 130.7121 5.26 Q V
14 +30 130.8267 2.77 Q V
15+ 0 130.8798 1.29 Q V
• 15 +30 130.8978 0.44 Q V
1
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
+++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 10
Antecedent Moisture Condition = 2
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 10
655.20 1 0.92
Rainfall data for year 2
- 655.20 6 1.63
Rainfall data for year 2
655.20 24 3.10
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 2) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 56.0 84.00 0.128 0.734 0.100 0.073
81.0 81.0 326.20 0.498 0.353 1.000 0.353
86.0 86.0 245.00 0.374 0.265 1.000 0.265
Area - averaged adjusted loss rate Fm (In /Hr)= 0.284
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC2) yield fr
8.40 0.013 56.0 56.0 7.86 0.215
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 81.0 2.35 0.604
245.00 0.374 86.0 86.0 1.63 0.699
Area - averaged catchment yield fraction, Y = 0.675
Area - averaged low loss fraction, Yb = 0.325
+ + ++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.555 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.444 hours
Unit interval = 30.000 minutes
.. Unit interval percentage of lag time = 112.6126
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.284 (In /hr)
Average low loss rate fraction (Yb) = 0.325 (decimal)
Valley Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.340 inches
Computed peak 30- minute rainfall = 0.697 inches
Specified peak 1 -hour rainfall = 0.920 inches
Computed peak 3 -hour rainfall = 1.656 inches
Specified peak 6 -hour rainfall = 2.399 inches
Specified peak 24 -hour rainfall = 5.116 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.330 inches
30- minute factor = 0.969 Adjusted rainfall = 0.676 inches
1 -hour factor = 0.969 Adjusted rainfall = 0.892 inches
3 -hour factor = 0.996 Adjusted rainfall = 1.649 inches
6 -hour factor = 0.998 Adjusted rainfall = 2.394 inches
24 -hour factor = 0.999 Adjusted rainfall = 5.112 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 22.815 301.303
2 73.686 671.828
3 87.568 183.326
4 93.298 75.667
5 96.397 40.928
6 98.291 25.011
7 99.408 14.759
8 100.000 7.815
Total soil rain loss = 1.62 (In.)
Total effective runoff = 3.49 (In.)
Total soil -loss volume = 88.6439 (Acre -Feet)
Total storm runoff volume = 190.3571 (Acre -Feet)
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
`` Hydrograph in 30 Minute intervals (CFS)
Time(h +m) Volume(AF) Q(CFS) 0 100.0 200.0 300.0 400.0
4 0 +30 0.4930 11.93 VQ
1+ 0 2.0927 38.71 V Q
• 1 +30 4.0160 46.55 V Q
2+ 0 6.0925 50.25 V Q
2 +30 8.2686 52.66 V Q
- 3+ 0 10.5210 54.51 V Q
3 +30 12.8354 56.01 V Q
4+ 0 15.2028 57.29 V Q
4 +30 17.6131 58.33 V Q
5+ 0 20.0689 59.43 VQ
- 5 +30 22.5730 60.60 V Q
6+ 0 25.1286 61.85 VQ
""" 6 +30 27.7393 63.18 VQ
7+ 0 30.4091 64.61 Q
7 +30 33.1425 66.15 Q
,., 8+ 0 35.9448 67.81 QV
8 +30 38.8217 69.62 Q V
-4 9+ 0 41.7802 71.60 QV
9 +30 44.8282 73.76 Q V
10+ 0 47.9751 76.15 Q V
10 +30 51.2320 78.82 Q V
11+ 0 54.6124 81.81 Q V
11 +30 58.1328 85.20 Q V
12+ 0 61.8141 89.09 Q V
12 +30 65.6671 93.24 Q V
13+ 0 69.7079 97.79 Q V
13 +30 74.0109 104.13 Q V
- 14+ 0 78.6519 112.31 Q V
14 +30 83.7919 124.39 Q V
°" 15+ 0 89.6781 142.45 Q V
15 +30 96.4096 162.90 Q V
16+ 0 105.0309 208.63 Q V
- 16 +30 118.6617 329.86 V Q
17+ 0 134.1361 374.48 V Q
46 ' 17 +30 142.9503 213.30 Q V
18+ 0 149.3173 154.08 Q V
18 +30 154.4919 125.22 Q V
. 19+ 0 158.9393 107.63 Q V
19 +30 162.8435 94.48 Q V
• 20+ 0 166.3243 84.23 Q V
20 +30 169.4699 76.12 Q V
21+ 0 172.4176 71.33 Q V
,, 21 +30 175.2068 67.50 Q V
22+ 0 177.8630 64.28 Q V
"°' 22 +30 180.4051 61.52 Q V
23+ 0 182.8479 59.11 Q V
- 23 +30 185.2030 56.99 Q V
., 24+ 0 187.4799 55.10 Q V
24 +30 189.2026 41.69 I Q V
25+ 0 189.7954 14.34 Q V
" 25 +30 190.0758 6.79 Q V
26+ 0 190.2262 3.64 Q V
26 +30 190.3065 1.94 Q V
. 27+ 0 190.3442 0.91 Q V
27 +30 190.3571 0.31 Q V
tW
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
... Study date 8/27/92
+++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 25
Antecedent Moisture Condition = 2
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 10
655.20 1 0
Rainfall data for year 2
655.20 6 1.63
Rainfall data for year 2
655.20 24 3.10
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 2) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 56.0 84.00 0.128 0.734 0.100 0.073
81.0 81.0 326.20 0.498 0.353 1.000 0.353
86.0 86.0 245.00 0.374 0.265 1.000 0.265
Area - averaged adjusted loss rate Fm (In /Hr)= 0.284
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC2) yield fr
I 98.0 0.013 56.0 56.0
98.0 7.86 0.280
75.60 0.115 98.0 0.20 0.960
1
326.20 0.498 81.0 81.0 2.35 0.659
245.00 0.374 86.0 86.0 1.63 0.744
Area-averaged catchment yield fraction, Y = 0.720
Area- averaged low loss fraction, Yb = 0.280
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.535 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.428 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 116.8224
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.284 (In /hr)
Average low loss rate fraction (Yb) = 0.280 (decimal)
Valley Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.404 inches
Computed peak 30- minute rainfall = 0.827 inches
Specified peak 1 -hour rainfall = 1.091 inches
Computed peak 3 -hour rainfall = 1.960 inches
Specified peak 6 -hour rainfall = 2.837 inches
Specified peak 24 -hour rainfall = 6.264 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.391 inches
30- minute factor = 0.969 Adjusted rainfall = 0.802 inches
1 -hour factor = 0.969 Adjusted rainfall = 1.058 inches
3 -hour factor = 0.996 Adjusted rainfall = 1.953 inches
6 -hour factor = 0.998 Adjusted rainfall = 2.832 inches
24 -hour factor = 0.999 Adjusted rainfall = 6.258 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 24.097 318.239
2 74.947 671.536
3 88.400 177.665
4 93.784 71.111
5 96.789 39.677
6 98.562 23.413
7 100.000 18.997
Total soil rain loss = 0.75 (In.)
Total effective runoff = 2.08 (In.)
Total soil -loss volume = 41.0623 (Acre -Feet)
Total storm runoff volume = 113.4802 (Acre -Feet)
I
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
6 -HOUR S T O R M
R u n o f f H y d r o g r a p h
V ,..Y
Hydrograph in 30 Minute intervals (CFS)
'ime(h +m) Volume(AF) Q(CFS) 0 125.0 250.0 375.0 500.0
0 +30 1.2311 29.79 V Q
1+ 0 5.1442 94.70 V Q
1 +30 10.0272 118.17 V Q
2+ 0 15.5921 134.67 V Q
2 +30 21.9372 153.55 V I Q
3+ 0 29.3191 178.64 V Q
3 +30 37.8490 206.42 V Q
4+ 0 48.8587 266.44 V Q
4 +30 66.2722 421.41 V Q
5+ 0 85.6360 468.60 V Q
5 +30 96.5834 264.93 Q V
6+ 0 104.4821 191.15 Q V
6 +30 109.7640 127.82 Q V
7+ 0 111.8036 49.36 Q V
1 7 +30 112.8263 24.75 Q V
8+ 0 113.2183 9.49 Q V
8 +30 113.4033 4.48 Q V
9+ 0 113.4802 1.86 Q• V
I
I
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
+++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 25
Antecedent Moisture Condition = 2
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 10
655.20 1 0.92
Rainfall data for year 2
655.20 6 1.63
Rainfall data for year 2
655.20 24 3.10
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 2) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 56.0 84.00 0.128 0.734 0.100 0.073
81.0 81.0 326.20 0.498 0.353 1.000 0.353
86.0 86.0 245.00 0.374 0.265 1.000 0.265
Area - averaged adjusted loss rate Fm (In /Hr)= 0.284
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC2) yield fr
8.40 0.013 56.0 56.0 7.86 0.280
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 81.0 2.35 0.659
- 245.00 0.374 86.0 86.0 1.63 0.744
Area - averaged catchment yield fraction, Y = 0.720
Area=4veraged low loss fraction, Yb = 0.280
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
:. , User entry of time of concentration = 0.535 (hours)
Watershed area = 655.20 acres
- Catchment Lag time = 0.428 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 116.8224
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.284 (In /hr)
-4 Average low loss rate fraction (Yb) = 0.280 (decimal)
Valley Developed S -Graph proportion = 0.130
- Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
- Computed peak 5- minute rainfall = 0.404 inches
Computed peak 30- minute rainfall = 0.827 inches
Specified peak 1 -hour rainfall = 1.091 inches
- Computed peak 3 -hour rainfall = 1.960 inches
Specified peak 6 -hour rainfall = 2.837 inches
Specified peak 24 -hour rainfall = 6.264 inches
_ Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.391 inches
30- minute factor = 0.969 Adjusted rainfall = 0.802 inches
1 -hour factor = 0.969 Adjusted rainfall = 1.058 inches
3 -hour factor = 0.996 Adjusted rainfall = 1.953 inches
6 -hour factor = 0.998 Adjusted rainfall = 2.832 inches
24 -hour factor = 0.999 Adjusted rainfall = 6.258 inches
U n i t H y d r o g r a p h
- + + + + + + + + + + ++ + + + + + ++ + ++++++ ++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 24.097 318.239
2 74.947 671.536
3 88.400 177.665
. 4 93.784 71.111
5 96.789 39.677
6 98.562 23.413
w 7 100.000 18.997
Total soil rain loss = 1.14 (In.)
Total effective runoff = 3.07 (In.)
Total soil -loss volume = 62.0954 (Acre -Feet)
Total storm runoff volume = 167.6638 (Acre -Feet)
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
. 12 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-
Hydrograph in 30 Minute intervals (CFS)
_--
Time(h +m) Volume(AF) Q(CFS) 0 125.0 250.0 375.0 500.0
0 +30 0.9624 23.29 VQ
1+ 0 3.9833 73.11 V Q
1 +30 7.6308 88.27 V Q
2+ 0 11.6075 96.24 V Q
- 2 +30 15.8375 102.37 V Q
3+ 0 20.2913 107.78 V Q
3 +30 24.9781 113.42 V Q
4+ 0 29.8675 118.33 V Q
4 +30 34.9127 122.09 VQ
- 5+ 0 40.0698 124.80 Q
5 +30 45.5272 132.07 Q
- 6+ 0 51.4021 142.17 QV
6 +30 57.9095 157.48 QV
7+ 0 65.3656 180.44 QV
- 7 +30 73.8955 206.42 QV
8+ 0 84.9052 266.44 VQ
- 8 +30 102.3188 421.41 V Q
9+ 0 121.6825 468.60 V Q
9 +30 132.6300 264.93 Q V
- 10+ 0 140.5287 191.15 Q V
10 +30 147.0347 157.45 Q V
11+ 0 152.7795 139.02 Q V
11 +30 157.8965 123.83 Q V
12+ 0 162.3714 108.29 Q V
12 +30 165.6122 78.43 Q V
13+ 0 166.6998 26.32 Q V
- 13 +30 167.2047 12.22 Q V
14+ 0 167.4708 6.44 Q V
14 +30 167.6052 3.25 Q V
15+ 0 167.6638 1.42 Q V
..
. U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
.,,®. +++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 25
Antecedent Moisture Condition = 2
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 10 `
655.20 1 0.92
Rainfall data for year 2
655.20 6 1.63
Rainfall data for year 2
655.20 24 3.10
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 2) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 56.0 84.00 0.128 0.734 0.100 0.073
81.0 81.0 326.20 0.498 0.353 1.000 0.353
86.0 86.0 245.00 0.374 0.265 1.000 0.265
Area - averaged adjusted loss rate Fm (In /Hr)= 0.284
�• * * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC2) yield fr
8.40 0.013 56.0 56.0 7.86 0.280
A 75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 81.0 2.35 0.659
245.00 0.374 86.0 86.0 1.63 0.744
Area - averaged catchment yield fraction, Y = 0.720
Area- averaged low loss fraction, Yb = 0.280
++ F++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.535 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.428 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 116.8224
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.284 (In /hr)
Average low loss rate fraction (Yb) = 0.280 (decimal)
Valley Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.404 inches
Computed peak 30- minute rainfall = 0.827 inches
Specified peak 1 -hour rainfall = 1.091 inches
Computed peak 3 -hour rainfall = 1.960 inches
Specified peak 6 -hour rainfall = 2.837 inches
Specified peak 24 -hour rainfall = 6.264 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.391 inches
30- minute factor = 0.969 Adjusted rainfall = 0.802 inches
1 -hour factor = 0.969 Adjusted rainfall = 1.058 inches
3 -hour factor = 0.996 Adjusted rainfall = 1.953 inches
6 -hour factor = 0.998 Adjusted rainfall = 2.832 inches
24 -hour factor = 0.999 Adjusted rainfall = 6.258 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 24.097 318.239
2 74.947 671.536
3 88.400 177.665
4 93.784 71.111
5 96.789 39.677
6 98.562 23.413
7 100.000 18.997
Total soil rain loss = 1.71 (In.)
Total effective runoff = 4.55 (In.)
Total soil -loss volume = 93.3654 (Acre -Feet)
Total storm runoff volume = 248.2187 (Acre -Feet)
" +++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
24 - H O U R S T O R M
- R u n o f f H y d r o g r a p h
Hydrograph in 30 Minute intervals (CFS)
- v w"
Time(h +m) Volume(AF) Q(CFS) 0 125.0 250.0 375.0 500.0
0 +30 0.7110 17.21 VQ
• 1+ 0 2.9322 53.75 V Q
1 +30 5.5815 64.11 V Q
- 2+ 0 8.4279 68.88 V Q
2 +30 11.4052 72.05 V Q
3+ 0 14.4805 74.42 V Q
3 +30 17.6470 76.63 V Q
4+ 0 20.8657 77.89 V Q
- 4 +30 24.1395 79.23 V Q
5+ 0 27.4716 80.64 V Q
5 +30 30.8658 82.14 V Q
• 6+ 0 34.3261 83.74 VQ
6 +30 37.8569 85.45 Q
- 7+ 0 41.4634 87.28 Q
7 +30 45.1512 89.24 Q
8+ 0 48.9268 91.37 Q
- 8 +30 52.7977 93.68 QV
9+ 0 56.7724 96.19 Q V
9 +30 60.8610 98.94 Q V
10+ 0 65.0750 101.98 Q V
10 +30 69.4285 105.35 Q V
11+ 0 73.9383 109.14 Q V
11 +30 78.6250 113.42 Q V
12+ 0 83.5145 118.33 Q V
12 +30 88.5596 122.09 Q V
- 13+ 0 93.7167 124.80 Q V
13 +30 99.1741 132.07 Q V
14+ 0 105.0491 142.17 Q V
14 +30 111.5565 157.48 Q V
15+ 0 119.0126 180.44 Q V
""" 15 +30 127.5424 206.42 Q V
- 16+ 0 138.5522 266.44 QV
16 +30 155.9657 421.41 V Q
m 17+ 0 175.3295 468.60 V Q
17 +30 186.2769 264.93 Q V
• 18+ 0 194.1756 191.15 Q V
18 +30 200.6817 157.45 Q V
19+ 0 206.4264 139.02 Q V
19 +30 211.5434 123.83 Q V
20+ 0 216.0183 108.29 Q V
- 20 +30 220.1885 100.92 Q V
21+ 0 224.1230 95.21 Q V
21 +30 227.8644 90.54 Q V
. , 22+ 0 231.4389 86.50 Q V
22 +30 234.8695 83.02 Q v
• 23+ 0 238.1743 79.98 Q V
23 +30 241.3678 77.28 Q V
24+ 0 244.4617 74.87 Q V
24 +30 246.7671 55.79 Q V
25+ 0 247.5343 18.57 IQ V
- 25 +30 247.8897 8.60 Q V
'26+ 0 248.0790 4.58 Q V
, 26 +30 248.1758 2.34 Q - V
27+ 0 248.2187 1.04 Q V
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
+++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 50
Antecedent Moisture Condition = 2
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 10
655.20 1 0.92
Rainfall data for year 2
655.20 6 1.63
Rainfall data for year 2
655.20 24 3.10
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 2) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 56.0 84.00 0.128 0.734 0.100 0.073
81.0 81.0 326.20 0.498 0.353 1.000 0.353
86.0 86.0 245.00 0.374 0.265 1.000 0.265
Area - averaged adjusted loss rate Fm (In /Hr)= 0.284
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC2) yield fr
8.40 0.013 56.0 56.0 7.86 0.323
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 81.0 2.35 0.691
245.00 0.374 86.0 86.0 1.63 0.770
Area - averaged catchment yield fraction, Y = 0.747
Area - averaged low loss fraction, Yb = 0.253
+- 0-+ TI-+++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.523 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.418 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 119.5029
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.284 (In /hr)
Average low loss rate fraction (Yb) = 0.253 (decimal)
Valley Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.452 inches
Computed peak 30- minute rainfall = 0.925 inches
Specified peak 1 -hour rainfall = 1.221 inches
Computed peak 3 -hour rainfall = 2.191 inches
Specified peak 6 -hour rainfall = 3.169 inches
Specified peak 24 -hour rainfall = 7.132 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.438 inches
30- minute factor = 0.969 Adjusted rainfall = 0.897 inches
1 -hour factor = 0.969 Adjusted rainfall = 1.183 inches
3 -hour factor = 0.996 Adjusted rainfall = 2.182 inches
6 -hour factor = 0.998 Adjusted rainfall = 3.162 inches
24 -hour factor = 0.999 Adjusted rainfall = 7.126 inches
U n i t H y d r o g r a p h
�. ++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 24.905 328.901
2 75.695 670.749
3 88.813 173.243
4 94.076 69.516
5 97.022 38.898
6 98.718 22.400
7 100.000 16.930
Total soil rain loss = 0.76 (In.)
Total effective runoff = 2.40 (In.)
Total soil -loss volume = 41.4166 (Acre -Feet)
Total storm runoff volume = 131.1706 (Acre -Feet)
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
6 - H O U R S T O R M
- R u n o f f H y d r o g r a p h
_
Hydrograph in 30 Minute intervals (CFS)
..-
Time(h +m) Volume(AF) Q(CFS) 0 150.0 300.0 450.0 600.0
0 +30 1.4707 35.59 V Q
"" 1+ 0 6.0412 110.61 V Q
1 +30 11.7176 137.37 V Q
2+ 0 18.1798 156.39 V Q
- 2 +30 25.5496 178.35 V (Q
3+ 0 34.1236 207.49 V Q
- 3 +30 44.0249 239.61 V Q
4+ 0 56.8660 310.75 V Q
4 +30 77.1751 491.48 V Q
5+ 0 99.4640 539.39 ( V Q
5 +30 112.0060 303.52 Q V
6+ 0 121.0733 219.43 Q V
6 +30 127.0862 145.51 Q v
7+ 0 129.3531 54.86 Q V
7 +30 130.4646 26.90 Q V
8+ 0 130.8936 10.38 Q V
8 +30 131.0914 4.79 Q V
9+ 0 131.1706 1.92 Q V
a.
..
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 50
Antecedent Moisture Condition = 2
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 10
655.20 1 0.92
Rainfall data for year 2
655.20 6 1.63
Rainfall data for year 2
655.20 24 3.10
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 2) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 56.0 84.00 0.128 0.734 0.100 0.073
81.0 81.0 326.20 0.498 0.353 1.000 0.353
86.0 86.0 245.00 0.374 0.265 1.000 0.265
Area - averaged adjusted loss rate Fm (In /Hr)= 0.284
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC2) yield fr
8.40 0.013 56.0 56.0 7.86 0.323
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 81.0 2.35 0.691
245.00 0.374 86.0 86.0 1.63 0.770
Area - averaged catchment yield fraction, Y = 0.747
Area - averaged low loss fraction, Yb = 0.253
+ -0V44++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.523 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.418 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 119.5029
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.284 (In /hr)
Average low loss rate fraction (Yb) = 0.253 (decimal)
Valley Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.452 inches
Computed peak 30- minute rainfall = 0.925 inches
Specified peak 1 -hour rainfall = 1.221 inches
Computed peak 3 -hour rainfall = 2.191 inches
Specified peak 6 -hour rainfall = 3.169 inches
Specified peak 24 -hour rainfall = 7.132 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.438 inches
30- minute factor = 0.969 Adjusted rainfall = 0.897 inches
1 -hour factor = 0.969 Adjusted rainfall = 1.183 inches
3 -hour factor = 0.996 Adjusted rainfall = 2.182 inches
6 -hour factor = 0.998 Adjusted rainfall = 3.162 inches
24 -hour factor = 0.999 Adjusted rainfall = 7.126 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 24.905 328.901
2 75.695 670.749
3 88.813 173.243
4 94.076 69.516
5 97.022 38.898
6 98.718 22.400
7 100.000 16.930
Total soil rain loss = 1.16 (In.)
Total effective runoff = 3.59 (In.)
Total soil -loss volume = 63.3142 (Acre -Feet)
Total storm runoff volume = 195.7682 (Acre -Feet)
-• +++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
12 - H O U R S T O R M
- R u n o f f H y d r o g r a p h
0,
_
Hydrograph in 30 Minute intervals (CFS)
s ..
Time(h +m) Volume(AF) Q(CFS) 0 150.0 300.0 450.0 600.0
0 +30 1.1907 28.81 VQ
1+ 0 4.8428 88.38 V Q
1 +30 9.2265 106.09 V Q
2+ 0 13.9947 115.39 V Q
2 +30 19.0584 122.54 V Q
3+ 0 24.3806 128.80 V Q
3 +30 29.9670 135.19 V Q
4+ 0 35.7875 140.86 V Q
4 +30 41.7446 144.16 VQ
5+ 0 47.7506 145.34 Q
5 +30 54.0862 153.32 QV
_p 6+ 0 60.9000 164.89 Q V
6 +30 68.4487 182.68 QV
7+ 0 77.1012 209.39 Q V
7 +30 87.0025 239.61 Q V
8+ 0 99.8436 310.75 Q
- 8 +30 120.1527 491.48 V Q
9+ 0 142.4416 539.39 V Q
"" 9 +30 154.9836 303.52 Q V
10+ 0 164.0509 219.43 Q V
10 +30 171.5665 181.88 Q V
11+ 0 178.2791 162.44 Q V
11 +30 184.2864 145.38 Q V
12+ 0 189.5995 128.57 Q V
12 +30 193.4187 92.43 Q v
13+ 0 194.6746 30.39 Q v
13 +30 195.2546 14.04 Q V
14+ 0 195.5569 7.31 Q V
14 +30 195.7057 3.60 Q V
15+ 0 195.7682 1.51 Q V
o
..
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
+++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 50
Antecedent Moisture Condition = 2
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 10
655.20 1 0.92
Rainfall data for year 2
655.20 6 1.63
Rainfall data for year 2
655.20 24 3.10
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
a SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 2) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 56.0 84.00 0.128 0.734 0.100 0.073
81.0 81.0 326.20 0.498 0.353 1.000 0.353
86.0 86.0 245.00 0.374 0.265 1.000 0.265
Area - averaged adjusted loss rate Fm (In /Hr)= 0.284
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC2) yield fr
8.40 0.013 56.0 56.0 7.86 0.323
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 81.0 2.35 0.691
245.00 0.374 86.0 86.0 1.63 0.770
Area - averaged catchment yield fraction, Y = 0.747
Area - averaged low loss fraction, Yb = 0.253
+++ T++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.523 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.418 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 119.5029
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.284 (In /hr)
Average low loss rate fraction (Yb) = 0.253 (decimal)
Valley Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.452 inches
Computed peak 30- minute rainfall = 0.925 inches
Specified peak 1 -hour rainfall = 1.221 inches
Computed peak 3 -hour rainfall = 2.191 inches
Specified peak 6 -hour rainfall = 3.169 inches
Specified peak 24 -hour rainfall = 7.132 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.438 inches
30- minute factor = 0.969 Adjusted rainfall = 0.897 inches
1 -hour factor = 0.969 Adjusted rainfall = 1.183 inches
3 -hour factor = 0.996 Adjusted rainfall = 2.182 inches
6 -hour factor = 0.998 Adjusted rainfall = 3.162 inches
24 -hour factor = 0.999 Adjusted rainfall = 7.126 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 24.905 328.901
2 75.695 670.749
3 88.813 173.243
4 94.076 69.516
5 97.022 38.898
6 98.718 22.400
7 100.000 16.930
Total soil rain loss = 1.76 (In.)
Total effective runoff = 5.36 (In.)
Total soil -loss volume = 96.1862 (Acre -Feet)
- Total storm runoff volume = 292.7398 (Acre -Feet)
"` +++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
- .�
Hydrograph in 30 Minute intervals (CFS)
A.
Time(h +m) Volume(AF) Q(CFS) 0 150.0 300.0 450.0 600.0
- 0 +30 0.8884 21.50 VQ
"' 1+ 0 3.6006 65.63 V Q
1 +30 6.8175 77.85 V Q
2+ 0 10.2670 83.48 V Q
. 2 +30 13.8711 87.22 V Q
3+ 0 17.5893 89.98 V Q
- 3 +30 21.4104 92.47 V Q
4+ 0 25.2923 93.94 V Q
4 +30 29.2386 95.50 V Q
• 5+ 0 33.2530 97.15 V Q
5 +30 37.3397 98.90 VQ
- 6+ 0 41.5035 100.76 VQ
6 +30 45.7494 102.75 Q
7+ 0 50.0834 104.88 Q
7 +30 54.5121 107.17 Q
8+ 0 59.0429 109.64 QV
- 8 +30 63.6843 112.32 QV
9+ 0 68.4463 115.24 Q V
9 +30 73.3403 118.44 Q V
10+ 0 78.3799 121.96 Q V
10 +30 83.5809 125.87 Q V
11+ 0 88.9628 130.24 Q V
11 +30 94.5492 135.19 Q V
• 12+ 0 100.3697 140.86 Q V
12 +30 106.3268 144.16 Q V
13+ 0 112.3328 145.34 Q V
_ 13 +30 118.6684 153.32 Q V
14+ 0 125.4822 164.89 Q V
- 14 +30 133.0309 182.68 Q V
15+ 0 141.6834 209.39 Q V
- 15 +30 151.5848 239.61 Q V
• 16+ 0 164.4258 310.75 Q V
16 +30 184.7349 491.48 i V Q
to 17+ 0 207.0238 539.39 I V Q
17 +30 219.5658 303.52 Q V
18+ 0 228.6331 219.43 Q V
18 +30 236.1488 181.88 Q V
19+ 0 242.8613 162.44 Q V
to 19 +30 248.8686 145.38 Q V
20+ 0 254.1817 128.57 Q V
°° 20 +30 259.1520 120.28 Q V
,,, 21+ 0 263.8544 113.80 Q V
21 +30 268.3359 108.45 Q V
.. 22+ 0 272.6247 103.79 Q V
22 +30 276.7471 99.76 Q V
23+ 0 280.7237 96.23 Q V
23 +30 284.5710 93.10 Q V
24+ 0 288.3024 90.30 Q V
al 24 +30 291.0558 66.63 Q V
25+ 0 291.9540 21.74 IQ V
25 +30 292.3675 10.01 Q V
26+ 0 292.5852 5.27 Q V
26 +30 292.6937 2.63 Q V
27+ 0 292.7398 1.12 Q V
r 6.
aaY
U n i t H y d r o g r a p h A n a l y s i s
- Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
A ++++++++++'+`++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
teM
San Bernardino County Synthetic Unit Hydrology Method
- Manual date - August 1986
Storm Event Year = 100
Antecedent Moisture Condition = 3
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
. Rainfall data for year 100
. 655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
" * * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
- SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 3) (Acres) Fraction (In /Hr) (dec.) (in /hr)
. 56.0 75.8 84.00 0.128 0.440 0.100 0.044
81.0 94.6 326.20 0.498 0.106 1.000 0.106
_ 86.0 97.2 245.00 0.374 0.055 1.000 0.055
Area - averaged adjusted loss rate Fm (In /Hr)= 0.079
A
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
. Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC3) yield fr
8.40 0.013 56.0 75.8 3.19 0.642
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 94.6 0.57 0.919
245.00 0.374 86.0 97.2 0.29 0.958
Area - averaged catchment yield fraction, Y = 0.935
. Area - averaged low loss fraction, Yb = 0.065
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
°., User entry of time of concentration = 0.505 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.404 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 123.7624
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.079 (In /hr)
Average low loss rate fraction (Yb) = 0.065 (decimal)
Va'lpe`y Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.500 inches
Computed peak 30- minute rainfall = 1.023 inches
Specified peak 1 -hour rainfall = 1.350 inches
Computed peak 3 -hour rainfall = 2.421 inches
Specified peak 6 -hour rainfall = 3.500 inches
Specified peak 24 -hour rainfall = 8.000 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.484 inches
30- minute factor = 0.969 Adjusted rainfall = 0.992 inches
1 -hour factor = 0.969 Adjusted rainfall = 1.309 inches
3 -hour factor = 0.996 Adjusted rainfall = 2.412 inches
6 -hour factor = 0.998 Adjusted rainfall = 3.493 inches
24 -hour factor = 0.999 Adjusted rainfall = 7.993 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 26.169 345.604
2 76.806 668.726
3 89.432 166.738
4 94.523 67.243
5 97.363 37.507
6 98.948 20.931
7 100.000 13.888
Total soil rain loss = 0.21 (In.)
Total effective runoff = 3.28 (In.)
Total soil -loss volume = 11.7160 (Acre -Feet)
Total storm runoff volume = 178.9003 (Acre -Feet)
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
6 -HOUR S T O R M
R u n o f f H y d r o g r a p h
Hydrograph in 30 Minute intervals (CFS)
- Time(h +m) Volume(AF) Q(CFS) 0 200.0 400.0 600.0 800.0
• - 0 +30 2.1336 51.63 V Q
1+ 0 8.5420 155.08 V Q
1 +30 16.4457 191.27 V Q
y. 2+ 0 25.4294 217.40 V Q
2 +30 35.6755 247.96 V Q
'" 3+ 0 '` 288.42 V Q
3 +30 61.3411 332.68 V Q
4+ 0 79.2888 434.33 V Q
- 4 +30 107.1247 673.63 V Q
5+ 0 136.6158 713.68 V Q
-" 5 +30 153.4309 406.93 Q V
6+ 0 165.7095 297.14 Q V
- 6 +30 173.7496 194.57 Q V
7+ 0 176.6595 70.42 Q V
7 +30 178.0284 33.13 Q V
8+ 0 178.5700 13.11 Q V
8 +30 178.8106 5.82 Q V
. 9+ 0 178.9003 2.17 Q V
.0
1
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
+++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
�YY
°®A
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 100
Antecedent Moisture Condition = 3
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * * *
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 3) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 75.8 84.00 0.128 0.440 0.100 0.044
81.0 94.6 326.20 0.498 0.106 1.000 0.106
86.0 97.2 245.00 0.374 0.055 1.000 0.055
Area - averaged adjusted loss rate Fm (In /Hr)= 0.079
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC3) yield fr
8.40 0.013 56.0 75.8 3.19 0.642
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 94.6 0.57 0.919
245.00 0.374 86.0 97.2 0.29 0.958
Area - averaged catchment yield fraction, Y = 0.935
Area - averaged low loss fraction, Yb = 0.065
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.505 (hours)
Watershed area = 655.20 acres
,, Catchment Lag time = 0.404 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 123.7624
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.079 (In /hr)
Average low loss rate fraction (Yb) = 0.065 (decimal)
Val try Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.500 inches
Computed peak 30- minute rainfall = 1.023 inches
Specified peak 1 -hour rainfall = 1.350 inches
Computed peak 3 -hour rainfall = 2.421 inches
Specified peak 6 -hour rainfall = 3.500 inches
Specified peak 24 -hour rainfall = 8.000 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.484 inches
30- minute factor = 0.969 Adjusted rainfall = 0.992 inches
1 -hour factor = 0.969 Adjusted rainfall = 1.309 inches
3 -hour factor = 0.996 Adjusted rainfall = 2.412 inches
6 -hour factor = 0.998 Adjusted rainfall = 3.493 inches
24 -hour factor = 0.999 Adjusted rainfall = 7.993 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 26.169 345.604
2 76.806 668.726
3 89.432 166.738
4 94.523 67.243
5 97.363 37.507
6 98.948 20.931
7 100.000 13.888
Total soil rain loss = 0.33 (In.)
Total effective runoff = 4.95 (In.)
Total soil -loss volume = 18.0813 (Acre -Feet)
Total storm runoff volume = 270.2810 (Acre -Feet)
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
12 - H O U R S T O R M
R u n o f f H y d r o g r a p h
Hydrograph in 30 Minute intervals (CFS)
- Time(h +m) Volume(AF) Q(CFS) 0 200.0 400.0 600.0 800.0
- ;' 0 +30 1.7757 42.97 V Q
1+ 0 7.0355 127.29 V Q
• 1 +30 13.2984 151.56 V Q
2+ 0 20.0915 164.39 V Q
2 +30 27.2922 174.26 V Q
• 3+ 0 " 1 ` - 34.8462 182.81 V Q
3+30 42.7524 191.33 V Q
• 4+ 0 50.9819 199.15 V Q
- 4 +30 59.3444 202.37 V Q
5+ 0 67.6877 201.91 Q
m 5 +30 76.4719 212.58 QV
6+ 0 85.9150 228.53 QV
• 6 +30 96.3849 253.37 Q V
7+ 0 108.3940 290.62 Q V
7 +30 122.1413 332.68 Q V
8+ 0 140.0889 434.33 VQ
8 +30 167.9249 673.63 V Q
9+ 0 197.4160 713.68 V Q
9 +30 214.2311 406.93 Q V
10+ 0 226.5097 297.14 Q V
• 10 +30 236.7768 248.46 Q V
11+ 0 246.0474 224.35 Q V
- 11 +30 254.3766 201.57 Q V
12+ 0 261.8571 181.03 Q V
12 +30 267.1613 128.36 Q V
• 13+ 0 268.8536 40.95 Q V
13 +30 269.6271 18.72 Q V
• 14+ 0 270.0218 9.55 Q V
14 +30 270.2083 4.51 Q V
15+ 0 270.2810 1.76 Q V
U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD /CIVILDESIGN, 1990, Version 2.2
Study date 8/27/92
+++++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
San Bernardino County Synthetic Unit Hydrology Method
Manual date - August 1986
Storm Event Year = 100
Antecedent Moisture Condition = 3
Area averaged rainfall intensity isohyetal data:
Sub -Area Duration Intensity
(acres) (hours) (inches)
Rainfall data for year 100
655.20 1 1.35
Rainfall data for year 100
655.20 6 3.50
Rainfall data for year 100
655.20 24 8.00
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
* * * * * * ** Area - averaged max loss rate, Fm * * * * * * **
SCS curve SCS curve Area Area Fp(Fig c6) Ap Fm
No.(AMCII) No.(AMC 3) (Acres) Fraction (In /Hr) (dec.) (in /hr)
56.0 75.8 84.00 0.128 0.440 0.100 0.044
81.0 94.6 326.20 0.498 0.106 1.000 0.106
86.0 97.2 245.00 0.374 0.055 1.000 0.055
Area- averaged adjusted loss rate Fm (In /Hr)= 0.079
* * * * * * * ** Area - Averaged low loss rate fraction, Yb * * * * * * * * **
Area Area SCS cn SCS cn S Pervious
(acres) fract (AMC2) (AMC3) yield fr
8.40 0.013 56.0 75.8 3.19 0.642
75.60 0.115 98.0 98.0 0.20 0.960
326.20 0.498 81.0 94.6 0.57 0.919
245.00 0.374 86.0 97.2 0.29 0.958
Area - averaged catchment yield fraction, Y = 0.935
Area - averaged low loss fraction, Yb = 0.065
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
User entry of time of concentration = 0.505 (hours)
Watershed area = 655.20 acres
Catchment Lag time = 0.404 hours
Unit interval = 30.000 minutes
Unit interval percentage of lag time = 123.7624
Hydrograph baseflow = 0.00 (CFS)
Average maximum watershed loss rate(Fm) = 0.079 (In /hr)
Average low loss rate fraction (Yb) = 0.065 (decimal)
Valley Developed S -Graph proportion = 0.130
Valley Undeveloped S -Graph proportion = 0.870
Foothill S -Graph proportion = 0.000
Mountain S -Graph proportion = 0.000
Desert S -Graph proportion = 0.000
Computed peak 5- minute rainfall = 0.500 inches
Computed peak 30- minute rainfall = 1.023 inches
Specified peak 1 -hour rainfall = 1.350 inches
Computed peak 3 -hour rainfall = 2.421 inches
Specified peak 6 -hour rainfall = 3.500 inches
Specified peak 24 -hour rainfall = 8.000 inches
Rainfall depth area reduction factors:
Using a total area of 655.20 acres (Ref: fig. E -4)
5- minute factor = 0.969 Adjusted rainfall = 0.484 inches
30- minute factor = 0.969 Adjusted rainfall = 0.992 inches
1 -hour factor = 0.969 Adjusted rainfall = 1.309 inches
3 -hour factor = 0.996 Adjusted rainfall = 2.412 inches
6 -hour factor = 0.998 Adjusted rainfall = 3.493 inches
24 -hour factor = 0.999 Adjusted rainfall = 7.993 inches
U n i t H y d r o g r a p h
++++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
Interval 'S' Graph Unit Hydrograph
Number Mean values (CFS)
1 26.169 345.604
2 76.806 668.726
3 89.432 166.738
4 94.523 67.243
5 97.363 37.507
6 98.948 20.931
7 100.000 13.888
Total soil rain loss = 0.51 (In.)
Total effective runoff = 7.48 (In.)
Total soil -loss volume = 27.7105 (Acre -Feet)
Total storm runoff volume = 408.5206 (Acre -Feet)
+++++++++++++++++++++++++++++++++++++ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + ++
24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
Hydrograph in 30 Minute intervals (CFS)
Time(h +m) Volume(AF) Q(CFS) 0 200.0 400.0 600.0 800.0
0 +30 1.3354 32.32 VQ
1+ 0 5.2721 95.27 V Q
1 +30 9.9052 112.12 V Q
2+ 0 14.8609 119.93 V Q
2 +30 z- 20.0309 125.11 V Q
3+ 0 25.3565 128.88 V Q
3 +30 30.8155 132.11 V Q
4+ 0 36.3592 134.16 V Q
4 +30 41.9925 136.32 V Q
5+ 0 47.7205 138.62 V Q
5 +30 53.5491 141.05 V Q
6+ 0 59.4847 143.64 V Q
6 +30 65.5345 146.41 VQ
7+ 0 71.7066 149.36 Q
7 +30 78.0100 152.54 Q
8+ 0 84.4551 155.97 QV
8 +30 91.0538 159.69 QV
9+ 0 97.8194 163.73 QV
9 +30 104.7680 168.16 Q V
10+ 0 111.9180 173.03 Q V
10 +30 119.2915 178.44 Q V
11+ 0 126.9150 184.49 Q V
11 +30 134.8213 191.33 Q V
12+ 0 143.0508 199.15 Q V
12 +30 151.4133 202.37 Q V
13+ 0 159.7566 201.91 Q V
13 +30 168.5407 212.58 Q V
14+ 0 177.9839 228.53 Q V
14 +30 188.4538 253.37 Q V
15+ 0 200.4629 290.62 Q V
15 +30 214.2101 332.68 Q V
16+ 0 232.1578 434.33 QV
16 +30 259.9937 673.63 V Q
17+ 0 289.4849 713.68 V Q
17 +30 306.2999 406.93 Q V
18+ 0 318.5786 297.14 Q V
18 +30 328.8457 248.46 Q V
19+ 0 338.1163 224.35 Q V
19 +30 346.4455 201.57 Q V
20+ 0 353.9260 181.03 Q V
20 +30 360.9485 169.94 Q V
21+ 0 367.6079 161.16 Q V
21 +30 373.9654 153.85 Q V
22+ 0 380.0584 147.45 Q V
22 +30 385.9225 141.91 Q V
23+ 0 391.5856 137.05 Q V
23 +30 397.0701 132.73 Q V
24+ 0 402.3945 128.85 Q V
24 +30 406.2606 93.56 Q V
25+ 0 407.4844 29.62 Q V
25 +30 408.0420 13.49 Q V
26+ 0 408.3293 6.95 Q V
26 +30 408.4665 3.32 Q V
27+ 0 408.5206 1.31 Q V
TEMPORARY STORM WATER RETENTION AREA REPORT
APPENDIX A - RETENTION AREA & HYDROLOGY MAP PLAN
(Sheet 1 of 1)
�# (Folded in Slip Jacket)
moor
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