FLOOD10395 ‎(2)‎

• County: Montezuma
• Community: Dolores
• Stream Name: Dolores River
• Title: Dolores River near Dolores, Colorado, Flood Insurance Study
• Date: 5/1/2004
• Prepared For: Dolores
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Floodplain Report/Masterplan

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Table 3
Average Monthly Precipitation
Dolores River Basin, Colorado
Cortez Dolores Mancos Rico Silverton Telluride
6153 ft 6940 ft 7030 ft 8827 ft 9278 ft 8792 ft
Month ill % ill % ill % ill % ill % in %
Jan 1.08 8% 1.77 10% 1.38 8% 2.47 9% 1.66 7% 1.64 7%
Feb 0.88 7% 1.48 8% 1.19. 7% 2.15 8% 1.54 6% 1.57 7%
Mar 1.10 9% 1.87 10% 1.61 10% 2.44 9% 2.10 9% 2.02 9%
Apr 0.93 7% 1.52 8% 1.21 7% 1.77 7% 1.69 7% 2.04 9%
May 0.96 7% 1.29 7% 1.20 7% 1.62 6% 1.50 6% 1.84 8%
Jun 0.46 4% 0.57 3% 0.49 3% 1.34 5% 1.40 6% 1.26 5%
Jul 1.15 9% 1.43 8% 1.77 11% 2.77 11% 2.75 11% 2.50 11%
Aug 1.51 12% 1.93 10% 1.89 11% 2.84 11% 3.10 13% 2.75 12%
Sep 1.19 9% 1.53 8% 1.45 9% 2.33 9% 2.72 11% 2.12 9%
Oct 1.45 11% 1.87 10% 1.63 10% 2.13 8% 2.35 10% 2.04 9%
Nov 1.04 8% 1.71 9% 1.31 8% 1.97 8% 1.45 6% 1.68 7%
Dec 1.04 8% 1.53 8% 1.29 8% 2.20 8% 1.75 7% 1.63 7%
Total 12.8 100% 18.5 100% 16.4 100% 26.0 100% 24.0 100% 23.1 100%

Source: National Oceanic and Atmospheric Administration (NOAA), National Weather Service (NWS),
provided by the National Climatic Data Center (NCDC).

5.6 Storm and Flood Characteristics. The majority ofthe major flooding on the Dolores

e River above McPhee Reservoir, Colorado, results from rapid melting of the basin snowpack

during the period of April to July. Moderate peaks, large volumes, and long duration of flows

characterize these flood hydro graphs. Rainfall on the snowpack followed by a rapid warming

trend has produced the largest snowmelt hydro graph peak flows. See Table 4 on the following

page for information about streamflow gages on the Dolores River and Lost Canyon Creek used

for this hydrology report and the observed rainflood and snowmelt peak flows (Reference 4-i).

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