FLOOD04209

• County: Gunnison
• Community: Gunnison
• Stream Name: Gunnison River, Tomichi Creek
• Basin: Gunnison
• Title: Floodplain Information Study
• Date: 1/12/1976
• Prepared For: Gunnison County
• Prepared By: Engineering Consultants
• Floodplain - Doc Type: Floodplain Report/Masterplan

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PRECIPITATION DATA

Three different sources of information for precipitation data were used in this
analysis. These sources include:

1. Precipitation data for local stations listed in Table 3 as reported

in the official weather bureau records.

2. N. O. A. A. Atlas 2, Precipitation Frequency Atlas of the

Western United States, Volume III, Colorado, U.S. Department

of Commerce.

3. Technical paper number 40, Rainfall Frequency Atlas of the United
States.

The recent large scale maps of the N. O.A.A. Atlas 2 do not have as extensive

precipitation durations or return periods as mentioned in T .P. 40. By combining these two

sources it was possible to develop depth-duration-frequency curves for both Gunnison River

and Tomichi Creek watersheds above the study area. Plates 2 and 3 present the graphs ob-

tained from this analysis. The details for deriving these graphs are given in Appendix 1.

Precipitation data for Gunnison, Cochetopa Creek, Sargents, Pitkin, Taylor Park,
Crested Butte, and Blue Mesa weather stations were compiled. This data covered the per-
iods corresponding to high runoff at the gaging stations of Gunnison River near Gunnison,
Colorado and Tomichi Creek at Gunnison, Colorado. Table 4 shows this data for the per-
iod 1918 and 1940 - 1974.

Examination of the data presented in Table 4 shows that frequently a number of

precipitation stations did not record any precipitation dUring the peak runoff periods. Fur-

ther, that precipitation was nor widespread over large areas during these periods. Exam-

ining the year 1918, and 1940 - 1974 period, it shows that only during years of

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