WSP12299

• File Number: 8282.600.10
• Description: Colorado River Annual Operating Reports
• Basin: Colorado Mainstem
• Date: 1/1/1975
• Author: USDOI/BOR
• Title: Operation of the Colorado River Basin 1975 Projected Operations 1976
• Water Supply Pro - Doc Type: Publication

Projeeted Plan of Operation
Under Criteria
30 for Current Year

Determination of
"602(a) Storage"

Section 602 (a) (3) of the Colo.
rado River Basin Project Act of
September 30, 1968 (P,L. 90-537).
provide, for the 'torage of Colo-
rado River water not required to
be released under article, 111 (c)
and 11I(d) of the Colorado River
Compact in Upper Basin reservoirs
to the extent the Secretary find,
it to be reasonably necessary to
assure Compact deliveries without
impairment of annual consumptive
u,e, in the Upper Basin. Article 11
of the "Criteria for Coordinated
Long.Range Operation of Colo-
rado River Reservoirs," pursuant
to the act,_ provides that the a.n.
nual plan of operation shall in-
clude a determination by the
Secretary of the quantity of water
considered necessary as of Sep-
tember 30 of the current year to
be in storage as required by sec-

tion 602(a) of P,L. 90-537 after
consideration of all applicable
laws and relevant factors includ-
ing, but not limited to: (a) his-
toric streamflows; (b) the most
critical period of record j (c)
probabilities of water ,upply; (d)
estiinated future depletions in the
Upper Basin, including the effects
of recurrence of critical periods of
water supply; (e) the "Report of
the Committee on Probabilities
and Te,t Studie, to the Task Force
on Operating Criteria for the
Colorado River," dated October
30, 1969, and ,uch additional
studies as the Secretary deems
necessary j (f) the necessity to
assure that Upper Basin consump-
tive uses are not impaired because
of failure to store sufficient water
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 detennined that the
active storage in Upper Basin res-
ervoirs forecast for September 30,
1976, on the basis of average run-
off during the current year, ex.
ceed, the "602 (a) Storage" reo
quirement under any reasonable
range of assumptions which might
be reali,tically applied to tho,e
items which he is directed to con-
sider in establishing this storage
requirement. Therefore, the ac-
cumulation of "602(a) Storage"
is not the criterion governing the
release of water during the current
year. The Lake Powell active stor-
age forecast for September 30,
1976, i, scheduled to he 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