WSP12033

• File Number: 8240.200.46.J
• Description: Ruedi Reservoir
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 3/1/1995
• Title: Report to the Colorado Water Conservation Board on 1994 Water Releases from Ruedi Reservior for Endangered Fish Habitat in the 15-Mile Reach of the Colorado River
• Water Supply Pro - Doc Type: Publication

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RECOVERY PR~R
1HE ENDANGE~S
{fOF 1HE UPPER COIORAID

RECEIVED

John Hamill,
Program llItector

Ralph Morgenweek,
Implementallon
Commltlee Chairman

u.s. Fish and Wildlife Service . P.O. Box 25486 . Denver Federal Center . Denver, Colorado 80225 . [phone]

ESICR Ruedi Reservoir Releases
Mail Stop 65115

MAR 3 J995

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Daries C. Lile, Director
Colorado Water Conservation Board
1313 Sherman Street
Denver, Colorado 80203

Dear Chuck:

The Colorado Water Conservation Board (Board) asked the Fish and Wildlife
Service (Service) to report on water released from Ruedi Reservoir in 1994 for
the endangered Colorado River fishes. The enclos~d ,_,.~t responds to that
request and serves as a concluding document to fulfill the Service's
contractual obligation with the Bureau of Reclamation (Reclamation). The
report discusses releases from Ruedi Reservoir and the effects of these
releases on the endangered fish in the IS-Mile Reach of the Colorado River
near Grand Junction, Colorado.

In summary, 1994 was a water-short year, and as a consequence, all
20,000 acre-feet of water available from Ruedi Reservoir for endangered fish
flow augmentation was utilized. The Service worked closely with Reclamation
and the Division Engineer to provide augmentation flow to the reach when flows
dropped below 600 cfs. This coordination of efforts allowed maintenance of
higher flows than otherwise would have occurred under dry conditions. The
increased flows improved habitat for endangered fish by increasing the depth
of pool habitats that are heaVily used by adult Colorado squawfish.

The population of Colorado squawfish is estimated to be around 200 adults in
the upper river (Palisade to Stateline). This population is expected to
increase in the next few years as a result of recolonization of the reach by a
1986 cohort ~hich now resides in the lower river. The life history of the
Colorado s uaw" s s awnin in the u e olorado River between
a 1 sa e and the Utah state 1 i ne larv i ft ' to downstream nur
areas ears in the lower Colorado 'ver b returnin -10
~pstream areas as adults, 1S complex life history complicates the
assessment of fish distribution and abundance. The relatively short period in
which flows have been managed for endangered fish in comparison to the life
history requirements of the fish also makes it difficult to detect the
benefits of Ruedi Reservoir releases. The increased pool depth provided by
Ruedi Reservoir releases does benefit adult Colorado squawfish by providing
additional habitat and moderating temperature stress during the late summer
and early fall.

U.S. Fish and Wildlife Service . U,S. 8<lreau of Reclamation . Westem Noa Power Administration . Colorado . Utah . Wyoming
Environmental Defense Fund . NationaJ Audubon Society . Colorado Wildlife Federation . Wyoming Wildlife Federation
Colorado Water Congress . Utah Water Users Association . Wyoming Water Development Association
Colorado River Energy Distributors Assoclation