WSP02717

• File Number: 822.600.10
• Description: Colorado River Annual Operating Plan - Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/2001
• Author: USDOI/BOR
• Title: Annual Operating Plan
• Water Supply Pro - Doc Type: Annual Report

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

approximately 131 t-.1CM (0.106 r-.1AF) at Crystal, the result of annual system maintenance and
spring runoff exceeding powerplant capacity. Releases up to 112 ems (3,960 cfs) occurred at
Crystal, with flows in the river below the tunnel in excess of92 ems (3,240 cfs). Blue Mesa
Reservoir reached a peak elevation of2,288.8 meters (7,509.1 feet), 3.1 meters (10.3 feet) from
full, on June 17, 2000.

In January 2000, a final draft report entitled "Flow Recommendations to Benefit Endangered
Fishes in the Colorado and Gunnison Rivers" was submitted to the Upper Colorado River
Recovery Program Biology Committee. The report, prepared by a multi-disciplinary team,
synthesizes research conducted on endangered fish in the Gunnison River and Colorado River
under the Upper Colorado River Recovery Program. This report presents flow recommendations
for two different river reaches, one forthe Lower Gunnison River near Grand Junction, Colorado,
and the other one for the Colorado River downstream from the Gunnison River. The Flow
Recommendations report will most likely be finalized by the Upper Colorado River Recovery
Program in 2000. Reclamation intends to initiate a NEP A process to implement the finalized flow
recommendations. An EIS will be prepared which describes the effects of operating the Aspinall
Unit to achieve the finalized flow recommendations.

For water year 200 1 operations, Blue t\.lesa Reservoir will be drawn down to at least an elevation
of2,283 meters (7,490 feet) by December 31, 2000, in order to minimize icing problems in the
Gunnison River. Blue Mesa will continue to be drawn down through April 200 I 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 objectives of the Aspinall Unit are to meet the delivery requirements of the
Uncompahgre Valley Project, to keep a minimum of8.5 ems (300 cfs) flowing through the Black
Canyon of the Gunnison National Park, and to maintain a minimum flow of8.5 ems (300 cfs)
below the Redlands Diversion Dam (located on the Gunnison River, 3.7 kilometers [2.3 miles]
upstream of the confluence with the Colorado River) during the summer months. Under the most
probable and ma.ximum probable inflow scenarios, Blue Mesa is expected to fill in the summer
of2001 and flows through the Black Canyon of the Gunnison National Park are expected to be
above the minimum release objective during the summer months. The Aspinall Unit reservoir
system in water year 2001 will be operated in a manner that will ensure that reasonable specific
test releases, for endangered fish. can be accommodated, The forecasted runoff for the spring
of2001 will be closely monitored to achieve these objectives_ To protect both the blue ribbon
trout fishery in the Black Canyon and recreation potential, releases during 200 I will be planned
to minimize large fluctuations in the daily and monthly flows in the Gunnison River below the
Uncompahgre Tunnel Diversion.

Navajo Resen'oir

The San Juan River basin experienced another very dry winter, the second in a row. The April
through July inflow into Navajo Reservoir in water year 2000 was 416 MCM (0.337 MAF), or

November 16, 2000

9