WSP12329

• File Number: 822.600.10
• Description: Colorado River Annual Operating Plan - Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/1995
• Author: USDOI/BOR
• Title: Annual Operating Plan
• Water Supply Pro - Doc Type: Annual Report

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Blue Mesa, Morrow Point, and Crystal Reservoirs (Aspinall Unit)

In water year 1994 the April through July runoff into the Aspinall Unit was 760 MCM
(0.620 MAp) or 68 percent of average, Water year 1994 unregulated inflow is expected to
be 1,135 MCM (0.922 MAF) or 73 percent of average. With this level of inflow
approximately 106 MCM (0.086 MAF) of water bypassed the powerplant at Crystal, but no
bypasses occurred at Blue Mesa or Morrow Point. Releases of up to 113 m31s (4,000 cfs)
occurred at Crystal with flows in the river below the tunnel in excess of 88 m31s (3,100 cfs).
Large fluctuations in releases on a daily and hourly basis were avoided. Blue Mesa filled in
water year 1994. /
)

Section 7 consultation with j,e Fish and Wildlife Service on the operation of the Aspinall
Unit was continued in 199'Ji' As part of this consultation, a five year plan to study the effect
of various release patterns on habitat and possibly on the reproductive success and /J
reintroduction of endangered fish in the Gunnison River was outlined. Water year 19~ was
the ffi]f(t year of this five year study.
~d'~""

Additionally, the Aspinall Unit was operated as if the draft contract between Reclamation,
the National Park Service, and the State of Colorado to deliver water from the Aspinall Unit
to the Black Canyon of the Gunnison National Monument were in place. The operation was
also coordinated with the Fish and Wildlife Service and others interested in the operation of
the Aspinall Unit.

For water year 1995 operations, Blue Mesa Reservoir will be drawn down to at least an
elevation of 2283.0 m (7490 feet) by December 31, 1994 in order to minimize icing
problems in the Gunnison River. Blue Mesa will continue to be drawn down through
April 1995 to a level that will accommodate the most probable inflow scenario and
accomplish the release objectives with minimum powerplant bypasses at Crystal.

The minimum release objective of the unit is to meet the delivery requirements of the
Uncompahgre Valley Project and to keep a minimum of 8.5 m31s (300 cfs) flowing through
the Black Canyon of the Gunnison National Monument. Under all three inflow scenarios,
Blue Mesa is expected to fill in the summer of 1995 and flows through the Black Canyon of
the Gunnison National Monument are expected to be above the minimum release objective
during the summer months. The filling of the reservoir next year will ensure that reasonable
specific releases required to study the protection and improvement of habitat for endangered
fish can be accommodated. The forecast runoff for the spring of 1995 will be monitored to
achieve these objectives. To protect the blue ribbon trout fishery in the Black Canyon and
maximize recreation potential. releases during 1995 will be planned to minimize large
fluctuations in the daily and monthly flows.

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