WSP02638

• File Number: 8210.140.20
• Description: Colorado River Basin Organizations and Entities - Colorado River Basin States Forum - California
• State: CA
• Basin: Western Slope
• Date: 1/1/1981
• Author: Myron B Holburt
• Title: Annual Report for the Calendar Year 1980
• Water Supply Pro - Doc Type: Annual Report

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Introduction

The Colorado River Board of
California is the State agency created
by the Legislature in 1937 for the
purpose of protecting the rights and
interests of the State, its agencies, and
its citizens in the water resources of
the Colorado River System. The duties
of the Board are set forth in Sections
12527 through 12533 of the California
Water Code. The activities of the
11-member staff are directed by the
Chief Engineer. The Cal.ifornia
Attorney General is legal counsel to
the Board.

The Board consists of a total of 11
members. Six members are appointed
by the Governor from the agencies
with Colorado River water and power
rights-City of Los Angeles
Department of Water and Power,
Coachella Valley Water District,
Imperial Irrigation District, The
Metropolitan Water District of
Southern California, Palo Verde
Irrigation District, and San Diego
County Water Authority. Three
additional members are appointed by
the Governor from the public, and the
Director of the Department of Water
Resources and the Director of the
Fish and Game Department or their
designees, are ex-officio members of
the Board. The Governor appoints a
Chairman from among the members
of the Board other than the latter two
members or their designees. Patricia
C. Nagle continued as Chairman of
the Board during 1980. Raymond R.
Rummonds was again elected to serve
as Vice Chairman of the Board.

Colorado River
Operations

Operations During 1980

The estimated virgin flow of the
Colorado River at Lee Ferry during
the 1979-80 water year (October 1
through September 30) was
17,497,000 acre-feet. This was 126
percent of the long-time average flow

of 13,917,000 acre-feet for the 59-year
period from 1922 through 1980. The
effects of this above-average flow,
occurring immediately after the 1979
water year which was also above
average, are described in the next
section.

During the water year, storage in
Upper Basin reservoirs increased by
2,178,000 acre-feet, and storage in
Lower Basin reservoirs increased by
1,401,000 acre-feet. Lake Powell filled
for the first time on June 22 and total
storage in Upper Basin reservoirs filled
to within 800,000 acre-feet of
capacity. As of September 30, 1980,
the active storage in the major Upper
Basin reservoirs was 28,883,000
acre-feet and the active storage in the
major Lower Basin reservoirs was
25,641,000 acre-feet. The actual flow
of the river below Glen Canyon Dam
at Lee Ferry for the water year was
10,967,000 acre-feet.

The U.s. Water and Power
Resources Service estimated the
1979-80 water year Upper Basin
depletions by the four Upper Basin
States of Colorado, New Mexico,
Utah, and Wyoming at 3,788,000
acre-feet, 130,000 acre-feet more than
the previous year.

Diversions less measured returns
from the mainstream for the major
water users of the Lower Basin States
of Arizona, California, and Nevada
were 6,018,000 acre-feet for calendar
year 1980, 51,000 acre-feet less than
in 1979. Data for major California
users show diversions less returns for
calendar year 1980 at 4,818,000
acre-feet, 73,000 acre-feet less than in
1979.

Deliveries of Colorado River water
to Mexico in accordance with the
1944 United States-Mexico Water
Treaty totaled 7,195,000 acre-feet
during calendar year 1980, or
5,695,000 acre-feet in excess of the
Treaty's guaranteed annual quantity.
Of this excess, about 155,000
acre-feet was covered under
provisions of Minute 242 of the
International Boundary and Water
Commission, the 1973 salinity
agreement with Mexico, and 200,000
acre-feet was chargeable to additional
scheduled flow under Article 10 (b) of
the Treaty which provides that when

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there exists a surplus, the United
States will provide 1,700,000 acre-feet
annually to Mexico. The remaining
5,340,000 acre-feet of excess
deliveries were due to floodwaters
from tributaries entering the Colorado
River below Hoover Dam and from
releases from Lake Mead in excess of
downstream requirements for the
purpose of creating flood control
storage space in rapidly filling
reservoirs. Minute No. 242 is
described in the Board's 1973 Annual
Report.
Last year's annual report described
the large quantities of surplus waters
delivered to Mexico during 1979
which cancelled the accumulated
debits as a result of Wellton-Mohawk
Drain discharges below Morelos Dam
from 1974 through 1979. These
discharges had been recognized by
the Department of the I nterior as
potential debits against the water that
will be salvaged as a result of the
future operation of the lined section
of the Coachella Canal. These surplus
waters have greatly exceeded the
amount of the Wellton-Mohawk Drain
flows. The construction of the lined
section of the Coachella Canal was
completed late in 1980 and is further
discussed in the Water Quality
Section.

High Colorado River Flows

Record-setting precipitation in the
Lower Colorado River Basin in early
1980 filled the water storage reservoirs
in the Upper Salt and Gila River
watersheds and almost filled the flood
control reservoirs on the Lower Gila
and Bill Wiliams Rivers. Flood control
releases from these two rivers,
combined with unusually high
streamflows on other tributaries below
Hoover Dam and excess releases
from mainstream Colorado River
reservoirs resulted in peak flows at the
Northerly International Boundary with
Mexico in excess of 11,000 cubic feet
per second. Approximately 5,000
cubic feet per second was temporarily
diverted by Mexico at Morelos Dam
into its irrigation distribution system in
order to ease the problems of
flooding the Colorado River Delta
area until river levees and flood
control channels could be enlarged.