WSP04347

• File Number: 8282.600.10
• Description: Colorado River Operating Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/1977
• Author: USDOI/BOR
• Title: Operation of the Colorado River Basin 1977 Projected Operations 1978
• Water Supply Pro - Doc Type: Publication

Enhancement of Fish
and Wildlife

Upper Basin

Forthe benefit offish habitat, the interim operating
rules for Fontenelle Reservoir provide a continuous
flow of at least 300 ft'ls in the channel immediately
below Fontenelle Dam, During water year 1977,
releases for power production and other purposes
provided flows of at least 500 ft'ls,

Fishing below Flaming Gorge Dam has been en.
hanced by maintaining a minimum 800 ft'ls
release to the river,

A release at least 76 ft'ls throughout the winter of
1976-77 assured good fish habitat in the river
below Taylor Park and Blue Mesa Reservoirs, Co.
ordinated operation between Taylor Park and Blue
Mesa Reservoirs in delivering irrigation water to
the Uncompahgre Project provided additional fish.
ery and recreation opportunities between the two
reservoirs. The interim operating rules specify a
minimum of 200 ft'ls to maintain fish habitat
below Crystal Dam and below the Gunnison Tunnel.

A continuous flow of at least 530 ft'ls was main.
tained throughout the year immediately below
Navajo Dam for fish propagation,

Clear water and a minimum release of 1,000 ft'ls
provided good habitat for introduced species of
fish in the river below Glen Canyon Dam,

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Topock Marsh on the Colorado River near Needles, Calif.
(Double-Crested Cormorants nesting).

Lower Basin

During the 1977 bass spawning season (March-
June), the Lake Mead water level declined approxi.
mately 13 feet. This decline in water level con.
tributed to a very poor black bass reproduction
season in 1977. The drought throughout the Colo.
rado River watershed and subsequent lack of spring
runoff resulted in lower releases from Glen Canyon
Dam. Consequently, Lake Mead could not be suffi.
ciently regulated to provide the stable or rising
water surface conducive to the bass spawn.

To provide satisfactory fish habitat along the lower
river and in Lake Havasu, releases from Lakes Mo.
have and Havasu were regulated so that minimum
flows were 1,960 ft'ls and the level of Lake Havasu
remained stable during the spring spawning
season.

Wild horses near Lake Havasu. Arizona-California.

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