1106

• UCREFRP Catalog Number: 1106
• Author: Gosse, J.
• Title: Microhabitat of Rainbow and Cutthroat Trout in the Green River Below Flaming Gorge Dam.
• USFW Year: 1982.
• USFW - Doc Type: Logan, UT.
• Copyright Material: NO

INTRODUCTION

Historical perspective

Flaming Gorge Dam, Utah was constructed as a hydroelectric

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project by the U.S. Bureau of Reclamation (US8R) and began opera-

tions in 1962. Previously, the Green River had been a turbid,

warm-water stream with vast flow fluctuations occurring between

the heavy spring runoffs and the low flows encountered during

much of the remainder of the year (USDA 1979). As the dam

filled, the tailwaters became clear and cold with normal annual

temperatures of 4 - 5 C as a result of the hypoliwnetic intakes.
When th€~dam was completed, a trout fishery was established

in the tailwater by the Utah Division of Wildlife Resources

(UDWR), with initially good rates of growth. As the dam filled,

discharge water temperatures decreased, and growth rates for the

trout decl ined (Schmidt et al. 1980).

At the request of the

UDWR, the tsBR constructed a multilevel intake system to allow

for release of warmer epil imnetic reservoir water from April to

December.

Thi s penstock modification became operational in June

1978, increasing mid-summer temperatures from 5 to 13 C. The

penstock modification was highly successful in the primary objec-

tive of producing increased growth rates for the trout (Larson et

a 1. 1982).

~luch of-..the area surrounding the reservoir and the riparian

land for 11 km below the dam has been designated a National

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