8056

• UCREFRP Catalog Number: 8056
• Author: Hamill, J.
• Title: Restoring and Protecting Instream Flows for Endangered Fish in the Upper Colorado River Basin.
• USFW Year: 1992.
• USFW - Doc Type: Denver, CO.
• Copyright Material: NO

2. Conduct a 5-year research program to allow for potential
refinement of the flows during the spring and winter
seasons.

3. Determine the feasibility and effects of releasing warmer
water during the late spring/summer seasons and
investigate the feasibility of increasing spring releases
by retrofitting river bypass tubes to include power
generation.

4. Legal protection of Green River flows from Flaming Gorge
Dam to Lake Powell.

The Service expects to finalize the biological opinion on Flaming
Gorge in the fall of 1992.

The Aspinall unit is a series of Reclamation dams on the Gunnison
River in Colorado. Beginning in 1992, Reclamation agreed to
reoperate the dams to provide flows that more closely resembled
historic conditions. The change in operations is being conducted
as part of a 5-year research program to evaluate the effects of
the operation of the Aspinall unit on endangered fish in the
Gunnison and Colorado Rivers.

The reoperation of the Reclamation dams to benefit the endangered
fish has not been without controversy. Concerns have arisen
about the effects of reoperation on hydropower production,
recreational boating (rafting), reservoir recreation and fishing,
and on the gold medal trout fisheries in the tailwaters below the
dams. All of these issues will be addressed by Reclamation in
accordance with the National Environmental Policy Act.

To date, major impacts of reservoir reoperation on the tailwater
trout fisheries have been avoided. In fact, releases from Ruedi
may have actually improved the trout fishery in the Frying Pan
River, according to the Colorado Division of wildlife. High
releases in the spring have the potential of adversely affecting
brown and rainbow trout reproduction in the Gunnison; however, it
appears that these impacts can be avoided by timing releases to
avoid major conflicts. It is important to note that native trout
evolved along with the endangered fish and are adapted to high
flows in the spring. It may be that the high releases, while
being an inconvenience to fisherman in the spring, may actually
enhance tailwater trout fisheries by providing flushing flows and
rejuvenating invertebrate production.

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