WSP04347

• File Number: 8282.600.10
• Description: Colorado River Operating Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/1977
• Author: USDOI/BOR
• Title: Operation of the Colorado River Basin 1977 Projected Operations 1978
• Water Supply Pro - Doc Type: Publication

River Regulation

During water year 1977, 8,226,000 acre.feet
were released from Glen Canyon Dam based on
measurements at the gaging station at Lees Ferry,
Ariz, For the 1.year and lD.year periods ending
September 30, 1977, 8,234,000 acre.feet and
88,272,000 acre.feet, respectively, passed the
compact point at Lee Ferry, Ariz. The expected reo
lease of 8,230,000 acre.feet from Lake Powell
scheduled for the year ending September 30, 1978,
is based on the most probable runoff. When added
to the flow of the Paria River, this will result in
Upper Basin delivery of about 88.1 million acre.
feet for the 10.year period ending September 30,
1978.

Water releases scheduled for the Colorado River
Storage Project and participating projects reser.
voirs were planned to accommodate all of the mul-
tiple purposes for which the project was designed,
in addition to the many day.to.day demands which
developed throughout the year,

Normally, daily releases are made from the storage
reservoirs in the'lower Basin to meet the 'lncoming
orders of the water user agencies. All water passes

through the powerplant units, The daily releases
are regulated on an hourly basis to meet, as nearly
as possible, the power loads of the electric power
customers. Minimum daily flows are provided in the
river to maintain fishery habitat. Adjustments to
the normal releases are made wilen conditions per.
mit to provide more satisfactory conditions for wa.'
ter.oriented recreation activities, to provide trans.
port for riverborne sediment to desilting facilities,
and to provide a degree of control of water quality,
Releases from Lake Powell during April, May, and
the first part of June for an integrated power op.
eration were not sufficient to maintain the normal
riverflows through the Grand Canyon for this pe.
riod nor to regulate for the Lake Mead bass fishery,
Flows in the Grand Canyon during the remainder of
the year were similar to those in past years and
proved to be satisfactory,

River regulation below Hoover Dam was accom.
plished in a manner which resulted in delivery to
Mexico of 277,913 acre.feet in excess of minimum
treaty requirements during water year 1977. Of
that quantity, 209,412 acre-feet were delivered for
salinity control pursuant to provisions of Minute
No. 242 of the Mexican Treaty,

Colorado River below Oavis Dam, California.

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