9318

• UCREFRP Catalog Number: 9318
• Author: U.S. Fish and Wildlife Service.
• Title: Procedures for Stocking Nonnative Fish Species in the Upper Colorado River Basin.
• USFW Year: 1996.
• USFW - Doc Type: Denver.
• Copyright Material: NO

Reclamation completed Section 7 consultation with the Fish and Wildlife
Service in April 1997 on current and projected discretionary routine lower Colorado
River operations and maintenance activities for a period of up to five years.
Reclamation and the Fish and Wildlife Service have also formed a partnership with
other federal, state and private agencies to develop the Lower Colorado River Multi-
Species Conservation Program. This program permits both non-federal and federal
parties to participate under Sections 7 and 10 of the ESA.
The following paragraphs discuss the operation of each of the reservoirs
with respect to compact, decree and statutory water delivery obligations and
instream flow needs for maintaining or improving aquatic resources, where
appropriate.
a. Fontenelle Reservoir
Precipitation and ensuing runoff in the Upper Green River Basin during
water year 1998 was near normal. The April through July runoff into Fontenelle
during water year 1998 was 925 MCM (0.750 MAF-, or 88 percent of normal.
Inflow peaked at 250 cubic meters per second (8,800 cfsl on June 2. Releases of
86 cubic meters per second (3,000 cfs) were made during much of June. No
flooding occurred in the city of Green River, Wyoming, located 60 river miles below
the dam. The flood stage is exceeded when flows at Green River exceed 354 cubic
meters per second (12,500 cfs1. Fontenelle Reservoir essentially filled in July of
1998 when the elevation of the reservoir came within 0.61 meters (two feet) of
reaching the crest of the spillway.
Because the mean annual inflow of 1,516 MCM (1.229 MAF) far exceeds
Fontenelle's storage capacity of 426 MCM (.345 MAF-, significant powerplant
bypasses are expected under the most probable and maximum probable inflow
scenarios. Additionally, there is little chance that the reservoir will not fill during
water year 1999. In order to minimize high spring releases and maximize
downstream resources and power production, the reservoir will probably be drawn
down to minimum pool elevation, 1970.0 meters (6,463 feet) which corresponds
to a volume of 115 MCM (0.093 MAF) of live storage.
b. Flaming Gorge Reservoir
Like Fontenelle Reservoir, inflows into Flaming Gorge were near normal
during water year 1998. April through July unregulated inflow was 1,357 MCM
(1.100 MAF), or 92 percent of normal.
During the operation of the powerplant in 1997, a failure occurred in one
of the bypass tubes, causing flooding of the powerplant and a shutdown of the
generators. While electrical damage to the generators was quickly repaired, the
steel liner and surrounding concrete of the outlet tube suffered significant damage.
Repairs were not completed until August 1998, and the spring operation of Flaming
Gorge had only the powerplant and the spillway available for use. Since spillway
release temperatures in the months following June would have been much higher
than powerplant release temperatures, potential emergency actions were closely
coordinated with natural resource management interests to minimize adverse
ecological impacts should the powerplant generators cease to function. Fortunately,
no spillway releases were required during water year 1998.
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