FLOOD04641

• County: Denver
• Community: All
• Stream Name: All
• Basin: South Platte
• Title: Proposed Hydrology for use in Hydraulic Analysis of FEMA Flood Studies and Restudies
• Date: 9/1/1989
• Prepared For: State of Colorado
• Prepared By: Resource Consultants
• Floodplain - Doc Type: Educational/Technical/Reference Information

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was modeled under AMC II soil conditions. Using current
criteri.., a 2-hour AMC III storm produces a considerably larger
peak flow. The RBD model was run using the 2-hour design storm
with AMC III conditions, and resulted in even higher peak
flows. ThIs was expected because of the full development
conditions assumed in the RBD study. The second difference in
the hydrologic assumptions is that the upper pond #2 (located
at WG-2) was not in place as assumed in the RBD and SLA report.
This pond has not been installed and is not planned for
construction In the near future, although it probably would not
effect the peak flows in the lower portion of the basin.

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TA!l.LE 12.3 -=- SUMMARY OF WG fEAK DISCHARGES BY RCI

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TAB!,]:; 12.2 -=- SUMMARY OF WG BASIN PARAMETERS
DRAINAGE AREA(l) CURVE NUMBER TIME OF
SUBBASIN ~ll miles) CN CONCENTRATION. Ie
1 0.06 [0.85] 65 0.20
2 0.00 [0.28] 60 0.00
3 0.27 [0.13 ) 60 0.60
4 0.02 [0.06J 60 0.30
5 0.31 60 0.68
6 0.24 62 1.05
7 0.19 62 0.55
8 0.07 66 0.52
9 0.37 64 0.87
10 0.28 69 0.90
11 0.42 81 0.98
12 0.59 65 1.06
13 0.26 63 0.94
14 0.41 84 0.25
15 0.15 88 0.08
16 0.27 81 0.16

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(1) Areas in brackets drain into depressions and are "noncontributing"
to flow downs tream.

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DRAINAGE AREA(2) PEAK DISCHARGES(l) llili
LOCATION {squar.!!. fil.les L 10 YR 50 YR 100 YR 500 YR
WG 1 0.30 60 120 150 250
WG 2 1. 16 240 570 720 1,300
WG 3 1. 81 410 970 1,210 2,300
WG 4 4.08 800 1,480 1,740 2,700
WG 5 3.49 690 1,210 1,460 2,200
WC 6 3.64 690 1,210 1,1,60 2,200
WC 7 3.91 720 1,210 1,460 2,200

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(1) These values result from the 2-hour AMC III storm.
(2) These values do not i.nclude "noncontributing" area flowing into
depress ion!::.

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R€~OURC€ CON~UlTI\NT~ INC

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