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

Water Quality Control

Water Quality Operations
During Water Year 1977

Since water quality aspects of Colorado River op-
erations are extensively described in the biennial
series of reports entitled "Quality of Water, Colo-
rado River Basin," only minimal discussion of this
aspect of operation is presented in this report, Re-
port No, 9 of the biennial series will be issued in
January 1979,

The Bypass Drain, a feature of the Colorado River
Basin Salinity Control Act, was constructed and be-
came operational in June 1977, Subsequently,
Wellton-Mohawk drainage waters have not been
discharged back to the Colorado River below Mor-
elos Dam but have been conveyed via the Bypass
Drain to the Santa Clara Slough in Mexico. This
action will prevent the poor quality waters from
seeping into the ground water which then migrates
toward the Mexican irrigation wells in the Mexicali
Valley, During water year 1977, the United States
bypassed 155,163 acre.feet to the Colorado River
below Morelos Dam and 54,249 acre-feet through
the Bypass Drain for a total of 209,412 acre-feet
which was replaced with a like amount of other
water, pursuant to Minute No, 242 of the Treaty
with Mexico_

Although water quality control is not generally rec-
ognized as a beneficial use of surface water, water
released for other purposes during normally low
flow periods can enhance the quality of water dur-
ing those periods,

In recognizing the need to manage water quality of
the Colorado River, it has been recommended that
salinity increases in the river be controlled through
a water quality improvement program generally de-
scribed in the Bureau of Reclamation's report,
"Colorado River Water Quality Improvement Pro-
gram,". dated February 1972, and a status report
of the same title dated January 1974. The program
calls for a basinwide approach to salinity control
while the Upper Basin continues to develop its com-
pact-apportioned waters. The initial step towards
improvement of the quality of the river's water was
authorization by the Congress (Public Law 93-320)
of the Colorado River Basin Salinity Control Proj.
ect, June 24, 1974.

Nevada Department of Fish and Game's Lake Mead fish
hatchery.

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