WSP01659

• File Number: 8282.600.10
• Description: Colorado River Operating Annual Reports
• Basin: Colorado Mainstem
• Date: 1/1/1974
• Author: USDOI/BOR
• Title: Operation of the Colorado River Basin 1974 Projected Operations 1975
• Water Supply Pro - Doc Type: Publication

Projected Plan of Operation
Under Criteria for Current Year.

DETERMINA nON OF "602(a) STORAGE"

Section 602(a)(3) of the Colorado River
Basin Project Act of September 30, 1968
(Public Law 90-537), provides for the storage
of Colorado lliver water not required to be
released under Articles 1I1(c) and lII(d) of the
Colorado River Compact in Upper Basin
reservoirs to the extent the Secretary finds it
to be reasonably necessary to assure Compact
deliveries without impairment of annual
consumptive uses in the Upper Basin. Article II
of the Criteria for Coordinated Long-Range
Operation of Colorado River Reservoirs
pursuant to that Act provides that the annual
plan of operation shall include a determination
by the Secretary of the quantity of water
considered necessary as of September 30 of the
current year to be in storage as required by
Section 602(a) of P.L 90-537 after
consideration of all applicable laws and relevant
factors, including, but not limited to the
following:

(a) Historic stream flows;
(b) The most critical period of record;
(c) Probabilities of water supply;
(d) Estimated future depletions in the
Upper Basin, including the effects of
recurrence of cri tical periods of water
supply;
(e) The "Report of the Committee on
Probabilities and Test Studies to the
Task Force on Operating Criteria for

the Colorado River," dated
October 30, 1969, and such
additional studies as the Sene tary
deems necessary;
(f) The necessity to assure that Upper
Basin consumptive uses not be
impaired because of failure to store
sufficien t wa ter to assure deliveries
under Section 602(a)( I) and (2) of
P.L. 90-537.

Taking into consideration these and other
relevant factors, the Secretary has determined
tha t the active storage in Upper Basin reservoirs
forecast for September 30, 1975, on the basis
of average runoff during the current year,
exceeds this "602(a) Storage" requirement
under any reasonable range of assumptions
which might be realistically applied to those
items which he is directed to consider in
establishing this storage requiremen t.
Therefore, .the -accumulation of "602(a)
Storage" is not the criterion governing the
release of water during the current year. The
Lake Powell active storage forecast for
September 30, 1975, is projected to be about
equal to the Lake Mead active storage forecast
for that date.
The plan of operation during the current
year based on average conditions is to release
about 8,736,000 acre-feet in accordance with
Section 602(a)(3) of Public Law 90-537.

26