WSP11872

• File Number: 8282.600.10
• Description: Colorado River Operating Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/1981
• Author: USDOI/BOR
• Title: Operation of the Colorado River Basin 1981 Projected Operations 1982
• Water Supply Pro - Doc Type: Publication

Parker Dam and Powerplant.

Upon 30 days advance notice to the United
States Section. Mexico has the right to modity,
within the total schedule, any monthly quantity
prescribed by the schedule by not more than
20 percent During water year 1 981. Mexico
received a total delivery of about 3,622,000
acre-teet at the Northerly Internalional
Boundary, Of that amount. it is estimated that
abou1379,000 acre-feet was attributable to
Gila River inflow (as measured al the gage
near Dome, Ariz.) and the remainder, about
3,243,000 acre-feet. was released from the
Colorado River mainstem reservoirs. The Gila
River inflow to the Colorado is a combination
of flood control releases from Painted Rock
Dam and irrigation return flows.

Of the 3,243,000 acre-feet of mainstem
Colorado River wa\el reaching the boundary,
abouI2,224,000 acre-feet was delivered
through Pilot Knob Powerplant wasteway from
the All-American Canal. An estimated 658,000
acre.feet was released through Laguna Dam.
The remainder of the flow at the Northerly
International Boundarywas made up of return
flows to the Colorado RIVer below Laguna
Dam, and returns to the Gila River below the
gaging station near Dome.

The United States will make scheduled
delIVeries of 1.500,000 acre-feet of Colorado
River water to the Republic of Mexico in
calendar year 1982, Representatives of the
Republic of Mexico will be kept informed of
operating schedules through the United
Stales Section of the Commission.

4

Regulatory Wastas

Deliveries to Mexico consist of river water
delivered to Imperial Dam and waste and
drainage return flows from water users below
Imperial Dam. In addition to assuring normal
water deliveries, the small amount of
regulatory storage space in Imperial, Laguna.
and Senator Wash Reservoirs was used at
times to limil potenlial downstream flood
damages during water year 1981, Regulatory
waste for water year 1982 will depend on the
actual hydrologic conditions occurring during
that time,

Additional Releases
Water Year 1981

Hoover Dam from a visitor's viewpoint.

On April 10, 1980. a meeting of Federal. Slale.
and basin interests 10 discuss "Colorado River
Basin Water Conditions" and proposed plans
for reservoir operations was held in Las
Vegas, Nev, The principal subject of
discussion at that meeting was the proposed
release of an average of 19.000 cubic feet per
second from Parker Dam, beginning May 1,
1980, and continuing through December 31,
1980, in order to avoid making tuture tlood-
condition releases and coincidentally. to
optimize power generation.

This plan of operation, including the further
additional releases, was implemented
consistent with the operational strategy
approved by the Assistant Secretary of the
Interior in 1979, During water year 1981. the
additional Hoover releases totaled
approximately 1,177.000 acre-feet. No
additional releases were made after January
1981,