8066

• UCREFRP Catalog Number: 8066
• Author: Harris, R. E.
• Title: Attachment 4, Gunnison River Study Flows - Aspinall Section 7 Consultation.
• USFW Year: 1992.
• USFW - Doc Type: Salt Lake City, Utah.
• Copyright Material: NO

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Attachment 4

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UNITED STATES DEPARTMENT OF THE INTERIOR
FISH AND Wll.DLIFE SERVICE
FISH AND Wll.DLIFE ENHANCEMENT
Field Supervisor's Office
2060 Administration Building
1745 West 1700 South
Salt Lake City, ur 84104-5110
FrS 588-5630
COMM [phone]

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PRI()(IN
AMERICA

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IN REPLY REFER TO:
FWEjCO:BR-Aspinall--Gunnison River Study flows
MS 65412 GJ

April 16, 1992

Memorandum

To: Projects Manager, Grand Junction Projects Office, Bureau of
Reclamation, Grand Junction, Colorado

From: Field Supervisor-COjUT, Fish and Wildlife Enhancement, Salt lake
City, Utah

Subject: Gunnison.River Study Flows - Aspinall Section 7 Consultation

In response to our memorandum of January 23, 1992, on the same subject, the
Fish and Wildlife Service (Service) received numerous comments and questions
regarding our recommendations for operational changes for the Aspinall Unit.
It became apparent from some of those comments that there was considerable
confusion and misunderstanding surrounding those recommendations.
Subsequently; the Service participated in a series of meetings with a variety
of personnel from State and Federal agencies and other interested parties to
answer questions and further clarify our position. Consistent with that
effort, we are continuing to work with your Operations Branch in the Salt. lake
City Regional Office to develop the hydrology documentation in support of
proposed study releases from Crystal Dam. Preliminary hydrology information
for the Gunnison River indicates that a redistribution of the flow regime at
Crystal Dam to mimic the natural hydrograph can be accommodated while
maintaining desired target elevations at Blue Mesa Reservoir. Depending on
annual storage levels prior to run-off and the particular water year forecast
(i.e., low, average, high) the overall shape of the hydrograph should remain
basically the same with the primary difference exhibited in the amplitude and
duration of the spring peak. As has already been established, the Service
plans to meet with Reclamation annually to coordinate studies and flow
releases related to the Aspinall Unit Section 7 consultation. As you know,
the Section 7 consultation scheduled to be completed in 1997 involves as-year
plan of study on the Gunnison River to assess the effects of operations on
listed species in both the Gunnison and Colorado rivers.

A critical component of the 5-year research program will be to provide test
flows from the Aspinall Unit to compliment the research effort. McAda and
Kaeding (1991), in Physical ChanQes in the Gunnison and Colorado Rivers
ResultinQ from Construction of the Aspinall Unit and Related Projects. with
Hvpotheses to Assess Effects on the EndanQered Fishes, recommended a range of
flows to be tested during the research period with an emphasis on spring peaks