WSP01172

• File Number: 822.600.10
• Description: Colorado River Annual Operating Plan - Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/1997
• 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 1996 the April through July unregulated runoff into Blue Mesa Reservoir was
1,024 MCM (.830 MAF) or 118 percent of average. Water year 1996 unregulated inflow
was 1,402 MCM (1.137 MAF) or 117 percent of average. Water year 1996 powerplant
bypasses were approximately 350 MCM (0.284 MAF) at Crystal. Releases and spills up to
270 ems (9,540 cfs) occurred at Crystal with flows in the river below the tunnel in excess of
243 ems (8,600 cfs). Blue Mesa filled easily during water year 1996.

Section 7 consultation with the Fish and Wildlife Service on the operation of the Aspinall
Unit continued in 1996. As part of this consultation, a five-year effort to study the effect of
various release patterns on habitat, reproductive success, and reintroduction of endangered
fish in the Gunnison River is underway.

Additionally, the Aspina1l 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 Aspina1l Unit.

For water year 1997 operations, Blue Mesa Reservoir will be drawn down to at least an
elevation of2283 meters (7490 feet) by December 31, 1996, in order to minimize icing
problems in the Gunnison River. Blue Mesa will continue to be drawn down.through
April 1997 to a level that will accommodate the current most probable inflow scenario and
accomplish the release objectives with minimal powerplant bypasses at Crystal.

The minimum release objective of the Aspina1l Unit is to meet the delivery requirements of
the Uncompahgre Valley Project and to keep a minimum of8.5 ems (300 cfs) flowing
through the Black Canyon of the Gunnison National Monument and to maintain a minimum
of 6 ems (200 cfs) below the diversion sttucture at Redlands (at the confluence of the
Gunnison and Colorado Rivers). Under all three inflow scenarios, Blue Mesa is expected to
fill in the summer of 1997 and flows through the Black Canyon of the Gunnison National
Monument are expected to be above the minimum release objective during the summer .
months. Fi1Iing of the reservoir in water year 1997 will ensure that reasonable specific
releases required to study the protection and improvement of habitat for endangered fish can
be accommodated. The forecasted runoff for the spring of 1997 will be closely monitored to
achieve these objectives. To protect both the blue "Dbon trout fishery in the Black Canyon
and recreation potential, releases during 1997 will be planned to minimize large fluctuations
in the daily and monthly flows in the Gunnison River below the Uncompahgre Tunnel
Diversion.

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