FLOOD00934

• Designation Number: 69
• County: Gunnison
• Community: Gunnison
• Stream Name: Gunnison River,Tomichi Creek
• Title: Floodplain Information Report - Gunnison River/Tomichi Creek, Gunnison, CO
• Date: 12/1/1976
• Designation Date: 7/1/1977
• Floodplain - Doc Type: Floodplain Report/Masterplan

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The va~iation of the quantity of th~ peak flood within the

Hudy reach""" studied.

From this analysis, it wa3 concluded that the

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runoff yield during periods of peak flow from the low lying areaa is
small. Thi~ result supports the ccncuIsion that snowmelt from upper
elevations is the major contributor to the peak flows.

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A detailed ana1y"!s of the precipitation data was conducted to

determine its impact on peak flows.

Examination of precipitation data

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revealed that frequently a number of atation~ did not re~ord any pre-
~ipitation during the p~ak runoff periods. Furth~r, that pre~ipitatton
~as not ~tdesprcad oVer large areas during the ssme periods. Only
during the years 1960, 1964 and 1973 appreciable precipitation over
widespread areas was recorded upstream of the study area. These periods
of high and widespread precipitation did not produce high frequency peak
runoff at Gunnison and Tomichi Creek runoff measuring stations located
in the study area.

Generally speaking, the more productive stream" of Western
Colorado have experienced large pea1<runoff rates duringyean of high
tempcraturc eombined "ith SnO~ paeks ",lth high ..,stcr cOnte"c. An
exception to this hs~ been the San Juan Mountains <Iress where rainstorms
have known to produce peak flo..,s.

A detailed descriotion of the hvdrolo~ie ansly"i~ and the re-
~ul<s obtai""d th"fdro," i~ includ"d in the Tccimical Addeudum.

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