FLOOD03485

• County: Denver
• Community: All
• Stream Name: All
• Basin: South Platte
• Title: Comparison of Estimated Flood Peaks with Historic Floods
• Date: 1/1/1986
• Prepared For: State of Colorado
• Prepared By: USDOI
• Floodplain - Doc Type: Educational/Technical/Reference Information

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'" 25G
a:
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H 20G
n
LL
0 HISTORIC PEAK ~ 154000 CFS-,
15G
w 281. OF PMF PEAK
t-
a:
'"
10G
5"

SSG
5UG
45e
40"
"
4-
0 35"
0
co
Q
3""

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PM, PEAK - 5~9B0B crs
PM, 36 HOUR VOLUME ... 287 7fH:l ACRE FEEl

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EUREAU OF RECLAMATION
PMF COMPARISON STUDY
PLUM CREEK NERR LOUVIERS COLORADO
LAF - 4.59 HOURS CHERRY CREEK DUH
PMP BRSED ON HMR 55

HISTORIC fLOOD ON JUNE 18 lBa~ PrAK. 1~4eee CFa
KLB 18/1/84

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J
96

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12 24 36 18 60 72
TIME FROM BEGINNING OF RAINFALL (hrs)

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Plate 48. - Computed PMF hydrograoh 3nd ~jstoric flood peak for Plum Creek near louv1ers, CO.

Table 37. - Basin averaged PM? for Plum Creek near Castle
Rock, CO,

Duration, Depth,
h In
1 10,97
2 14.40
4 18,76
6 21.87
12 25.20
24 2709

A lag time of 3,31 h was computed for thiS basin using an assumed C value of 1.2 and basin
parameters measured on available USGS topographic maps, This lag time generally corresponds
to the observed time of rapid rise at Louviers, approximately 3 h, and is consistent with other lag
time computations made in the area. Loss rates of 0,35 In (initial) and 0,33 in/h (constant) were
selected for this semiarid, sparsely vegetated area, The Cherry Creek DUH for front range streams
was used,

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Based on the data and assumptions descnbed, a PMF with 3 peak of 328,600 ft'/s was then
computed, The measured peak of 126,000 ftJ's represents 38 3 percent of the PMF peak for

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