7041

• UCREFRP Catalog Number: 7041
• Author: Upper Colorado River Commission.
• Title: Forty-Third Annual Report of the Upper Colorado River Commission
• USFW Year: 1991.
• USFW - Doc Type: Colorado River Storage Project and Participating Projects.
• Copyright Material: NO

eration of the uses of the reservoirs for all purposes, including flood
control, river regulation, beneficial consumptive uses, power production,
water quality control, recreation, enhancement of fish and wildlife, and
other environmental factors" (Operating eriteria Article I (2)). The
Annual Operating Plan stated that a "normal" water supply was available
for beneficial use in the Colorado River Basin.

During water year 1991:

1. The minimum release objective of8.23 million acre-feet was made
from Lake Powell.

2. No flood control releases were made from Lake Mead.

3. The guaranteed annual quantity of 1.5 minion acre-feet was
delivered to Mexico.

4. All requests by Lower Basin mainstream holders of surplus water
contracts in the U.S. are expected to be fully satisfied as ealifornia
water contract holders were allowed to use water apportioned to but not
used by the States of Arizona and Nevada.

5. Salinity provisions of Minute 242 were met.

2. RUNOFF AND RESERVOIR CONTENTS AND
RELEASES

In 1991, the snowmelt inflow into Lake Powell during the April
through July period totaled 5.3 maf or approximately 65 percent of the
1906-1985 average. The computed unregulated discharge at Lees Ferry
for the water year ending September 30,1991 was 8.4, which is approxi-
mately 71 percent of the 1906-1985 average. The following tabulation
lists the breakdown of discharges in acre-feet in the Upper eolorado River
Basin:

Net change in surface storage
Net change in bank storage
Net evaporation
Glen Canyon releases
Paria River discharge
Total Unregulated Discharge at Lees Ferry

Acre-feet
-359,000
-105,000
591,000
8,230,000
10,000
8,367,000

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