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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1997 RESERVOIR OPERATIONS

Minimum instream flow levels and annual operating strategies have been established at
severa1locations in the Upper and Lower Basins which are intended to protect the aquatic
resources downstream of specific dams. The regulation of the Colorado River has had both
positive and negative effects on aquatic resources. Controlled cool water releases from darns
have provided for increased productivity of some aquatic resources and the development of
significant sport fisheries. However, the same releases may be detrimental to endangered
and other native species of fishes.

Consultations with the Fish and Wtldlife Service in compliance with Section 7 of the
Endangered Species Act (Section 7 consultations) on the operation of the Aspinall Unit on
the Gunnison River, Navajo Dam on the San Juan River, and Flaming Gorge on the Green
River will continue in 1997. Studies associated with these consultations will be used to
better understand the flow related needs of endangered and other native species offish. The
issuance of the Record of Decision of the Glen Canyon Dam Environmental Impact
Statement (GCDEIS) replaced interim flow restrictions on releases from Lake Powell with
the preferred alternative of the GCDEIS.

Modifications to planned operations may be made based on changes in forecast conditions.
However, due to the Recovery hnplementation Program for Endangered Fish Species in the
Upper Colorado River Basin, Section 7 consultations, and other downstream concerns,
modification to the monthly operation plans may not be based solely on changes in
streamflow forecasts. Decisions on spring peak releases and downstream habitat target flows
may be made midway through the runoff season. Reclamation and the Fish and Wtldlife
Service will initiate meetings with interested parties, including representatives of the Basin
States, to facilitate the decisions necessary to finalize site specific operations plans. All
operations will be undertaken subject to the primary water storage and delivery requirements
established by "The Law of the River" and other applicable statutes, including water quality
control, recreation, enhancement offish and wildlife, and other environmental factors.

The following paragraphs discuss the operation of each of the reservoirs with respect to
compact, decree and statutory water delivery obligations, and instream flow needs for
maintaining or improving aquatic resources, where appropriate.

Fontenel1e Reservoir

The Upper Green River Basin experienced another above average year. The April through
July runoff into the reservoir during water year 1996 was 1,296 MCM (1.051 MAF) or
124 percent of the long tenn average and Fontenelle easily filled in 1996.

Because the mean annual inflow of 1,480 MCM (1.229 MAF) far exceeds the storage
capacity of 426 MCM (.345 MAF), significant powerplant bypasses are expected under the
most probable and maximum probable inflow scenarios. Additionally, there is Ii!tle chance

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