8182

• UCREFRP Catalog Number: 8182
• Author: Bestgen, K. R. and L. W. Crist.
• Title: Response of the Green River Fish Community to Construction and Re-regulation of Flaming Gorge Dam. 1962-1996\
• USFW Year: 2000.
• Copyright Material: NO

(CRSP) to store water so that states of the Upper and Lower Colorado River basins (Wyoming,
Colorado, Utah, New Mexico, Nevada, Arizona, California) could develop their respective water
entitlement. The dam and reservoir also produce hydropower and have fish and wildlife benefits.
Mean annual discharge in Green River upstream of the Yampa River has not changed
appreciably as a result of dam closure; 59 m3/s postdam versus 56 m3/s predam. However,
seasonal flow variability has been considerably reduced. Since Flaming Gorge Dam was closed
in 1962, June mean annual maximum flow of the Green River have been reduced from 381 m3/s
to 139 m3/s (Tyus and Karp 1991, Muth et al. 1999). Flow at other times of the year has
increased. In addition, releases for peaking power production were made up to twice per day,
resulting in short-term daily fluctuations. Annual volume of sediment transported by the Green
River below Flaming Gorge Dam has decreased by 54 % as a result of storage in the reservoir
(Andrews 1986).
The relatively unregulated Yampa River, a major tributary of the Green River, exhibits
greater seasonal and more stable daily flows than the Green River below the dam. During the
period 1963-1996, annual flow maxima in the seasonally variable and unregulated Yampa River
occasionally reached 566 m3/s, but sometimes declined to < 2 m3/s in late summer (U. S.
Geological Survey records, Maybell Gauge, 09251000).
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