Operating Criteria
Section 602(a) of the Colorado River Basin Project Act of
September 30, 1968, 82 Stat. 885,
directed the Secretary of the Interior to "propose criteria
for the coordinated long-range operation of
the reservoirs constructed and operated under the authority
of the Colorado River Storage Project
Act, the Boulder Canyon Project Act, and the Boulder Canyon
Project Adjustment Act" and to
receive comments from the States.
The need for the criteria was the concern of the Upper
Basin States as to their ability to recapture
from a new project in the Lower Basin presently unused
water apportioned to the Upper Basin when
needed for their own development. As a result of
negotiations the Basin Project Act contained a list
of priorities to govern the storage of water in storage
units of the Storage Project and releases of
water from Lake Powell. The Act also provided that the
Upper Basin's rights to the consumptive use
of water apportioned to that Basin by the Colorado River
Compact would not be prejudiced or
reduced by any use thereof in the Lower Basin. In other
words, storage in Lake Powell is the
cornerstone of the Upper Basin's ability to deliver water
to the Lower Basin to fulfill the
requirements of Articles III(c) and (d) of the Compact and,
at the same time, permit Upper Basin
consumptive uses. Article III(c) deals with deliveries to
Mexico and III(d) deals with deliveries of 75
maf to the Lower Basin each 10 years. The criteria were to
be prepared and reviewed each year
after an exchange of views with the States and affected
parties.
The objective of the legislative requirements for the
criteria was more efficient and reasonable river
management. At the same time augmentation was emphasized in
an effort to minimize the
controversy over the Upper Basin's share of contribution to
Mexico and whether the Gila River flows
are accountable therefor. An example was the requirement
that the first priority for the release of
water from Lake Powell is to satisfy one-half of the
deficiency in deliveries of water to Mexico, if
any such deficiency exists and is chargeable to the States
of the Upper Basin, but that the priority
shall not apply in any year that the river is augmented
sufficiently to satisfy the Treaty requirements
and associated losses. Among other major issues involved
in the discussions over the criteria were:
Lake Powell bank storage; estimates of Upper and Lower
Basin depletions; the use and magnitude of
a specific figure for releases from Lake Powell (e.g., 8.23
maf; continuation of the Filling Criteria;
and the use of a rule curve to accumulate storage in the
Upper Basin reservoirs.
On June 8, 1970, after evaluation of the comments of the
Upper and Lower Basin States, Secretary
Hickel adopted the Operating Criteria. A letter of June 9,
1970, from the Commissioner of
Reclamation explained the rationale of the decisions on
these comments. The Secretary concluded
that the Filling Criteria would be continued, that energy
needed to replace Hoover Dam deficiencies
would be purchased, that the Upper Colorado River Basin
Fund will be reimbursed pursuant to
Section 502 of the Basin Project Act for monies used
therefrom to purchase energy, except that the
costs incurred in connection with impairment of capacity
and energy resulting from the drawdown of
Lake Mead below elevation 1123 feet incident to the
attainment of minimum power pool in Lake
Powell would not be repaid.
The criteria for coordinated long-range operation of
Colorado River reservoirs, approved June 8,
1970, include the following provisions:
The Secretary may modify them from time to time and will
sponsor a formal review at least every 5
years with the States participation. The Secretary shall
transmit to Congress and the Basin States
Governors an annual report, starting January 1, 1972, and
each January 1 thereafter, describing
actual operations for the preceding compact water year and
the projected plan of operation for the
current year (Article I(1)).
The plan of operation shall include a determination by the
Secretary of the quantity of water
considered necessary to be in storage as of September 30 of
that year as required by Section 602(a)
of Public Law 90-537 ("602(a) Storage"). The factors to be
considered in arriving at that
determination are listed; e.g., historic streamflow, the
most critical periods of record, and
probabilities of water supply, estimated storage depletions
in the Upper Basin, including the effects
of recurrence of critical periods of water supply, the
report of the committee on probabilities and test
studies dated October 30, 1967, and the necessity to assure
that Upper Basin consumptive uses not
be impaired because of failure to store sufficient water to
assure delivery under Section 602(A)(1)
and (2), Public Law 90-537 (Article II(1)).
If, in the plan of operation, either
(a) the Upper Basin storage reservoirs active storage
forecast for September 30 of the current
year is less than the quantity of Section 602(a) storage
determined for that date, or
(b) the Lake Powell active storage forecast for that date
is less than the Lake Mead active
storage forecast for that date, the objective shall be to
maintain a minimum release from Lake Powell
of 8.23 maf for that year (Article II(2)).
Importantly, if the Upper Basin storage reservoirs active
storage forecast for September 30 of the
current water year is greater than the quantity of 602(a)
storage, water shall be released annually
from Lake Powell at a rate greater than 8.23 maf to
accomplish the following objectives:
(a) To the extent it can be reasonably applied in the Lower
Division States, but no such
release shall be made when the active storage in Lake
Powell is less than the active storage in Lake
Mead;
(b) To maintain, as nearly as practicable, active storage
in Lake Mead equal to the active
storage in Lake Powell; and
(c) To avoid anticipated spills from Lake Powell (Article
II(3)).
In the application of Article 11(3) the objective will be
to pass the releases through Glen Canyon
Powerplant as soon as practicable, utilizing the available
capability of the powerplant, in order to
equalize the active storage in Lake Powell and Lake Mead
(Article II(4)).
Releases from Lake Powell pursuant to the criteria shall
not prejudice either Basin's interests with
respect to required deliveries at Lee Ferry pursuant to the
Compact (Article II(5)).
Lake Mead is to be operated to meet Mexican Treaty
obligations, reasonable consumptive use
requirements of mainstream users in the Lower Basin, net
river and net reservoir losses, and
regulatory waste (Article III(1)).
Until Central Arizona Project water deliveries are made,
Lower Basin reasonable consumptive use
requirements will be met (Article III(2)). Thereafter, the
consumptive use requirements will be met in
light of the following situations: normal (7.5 maf);
surplus (i.e., quantities greater than normal); and
shortage (i.e., insufficient water to satisfy 7.5 maf
annual consumptive use requirements) (Article
III(5)). The criteria specified the relevant factors to
consider in connection with "surplus" and
"shortages." Definitions are contained in Article IV.
In the actual operations under the Operating Criteria the
annual reports have avoided the
determination of the numerical value for Section 602(a)
storage by stating that "the accumulation of
602(a) storage is not the criteria governing the release of
water during the current year."
In 1975 the first formal 5-year review of the criteria was
made, but after receipt of comments, the
Secretary announced their continuation without change.
Subsequent reviews of the Criteria in 1980,
1985, 1990 and 1995 have also resulted in no changes being
made to the Operating Criteria.
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