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Filling Criteria
As construction progressed on the Upper Basin storage units
authorized by the Colorado River
Storage Project Act of April 11, 1956, 70 Stat. 105,
including Glen Canyon Dam, Secretary of the
Interior Udall, in consultation with various interests in
the Colorado River Basin, initiated studies to
determine how Lake Powell could accumulate storage with the
least possible disruption of the many
activities, including power production at Hoover Dam, then
dependent upon the flow of the river not
being restricted in the Upper Basin.
Starting in October 1957, meetings of Basin States
representatives were held with Interior officials at
which hydrological data was considered. These were later
refined by engineering groups of both
Basins. Among the conflicting Upper and Lower Basin views
were the obtaining of minimum power
head at Glen Canyon Reservoir (elevation 3490 or 6.1 mat)
at the earliest practicable time and at the
same time dealing with any deficiency that might occur in
the firm energy generation at Hoover
Powerplant incident to filling the Upper Basin Storage
Project reservoirs.
On January 16, 1960, Reclamation proposed a set of
principles and operating criteria (later termed
"Filling Criteria"). These, it should be noted, were based
upon a reasonable exercise of Secretarial
discretion without attempting to define the outer limits of
either rights or obligations of any of the
States or of the United States. These principles were
issued February 12, 1960, and were revised
following receipt of comments and suggested modifications
in a series of meetings extending from
March 1960 to May 1961.
On April 2, 1962, Secretary Udall approved Reclamation's
redraft of the general principles which
appeared in the Federal Register of July 19, 1962, 27 F.R.
6851. The most controversial of the
principles was No. 5, which was that an allowance should be
made for computed deficiency in arm
energy generation at Hoover which might be caused by the
four storage units in the Upper Basin;
i.e., Glen Canyon, Flaming Gorge, Curecanti, and Navajo,
but excluding the effects of evaporation
from the surface of such reservoirs as a part of the
theoretical streamflow used in the formula for
computing allowance. (The initial draft considered only the
presence of Glen Canyon on the river and
was silent regarding evaporation losses.)
The allowance for computed deficiencies in Hoover arm
energy is the difference between two
calculations - the first in the so-called Hoover basic
firm, which is the firm energy that would have
been produced at Hoover without the four storage reservoirs
on the river and using an overall
efficiency factor for power operations of 83 percent. The
second calculation would be to adjust the
energy actually generated at Hoover to an efficiency factor
of 83 percent (rather than 70-78 percent
efficiency actually experienced).
The Secretary would determine how the allowance would be
accomplished; i.e., (1) monetarily, if the
incremental cost, that is, fuel replacement cost of
generating substitute energy, is less than the selling
rate for power from the Upper Basin projects, or (2)
whether it might be well to compensate the
Hoover Dam power contractors with kilowatt hours through
the interconnection of the two power
systems.
This principle, in particular, was vigorously attacked by
the Upper Basin States as without legal basis
and as implying a responsibility on the Upper Basin for
energy deficiencies at Hoover which they
denied. However, Principle No. 5 made provision for
reimbursing the Upper Basin Fund after 1987
from Hoover Dam power revenues for purchasing power to meet
Hoover deficiencies, but not for
confirm or other energy from the storage project's
powerplants. Interior's intention to secure
reimbursement was reflected in an Additional Regulation No.
1 to the General Regulations for
Generation and Sale of Power in accordance with the Boulder
Canyon Project Adjustment Act,
adopted by Secretary Udall on July 12, 1962, 27 F.R. 6850,
which stated that the rates to be charged
for electric energy after 1987 would include a component to
return to the United States funds
adequate to reimburse the Upper Basin Fund. No interest
would be included in the reimbursement.
Reclamation indicated its intention to make minimum use of
dollars and maximum use of energy
from Federal powerplants, but not firm energy, which would
otherwise be sold at firm power rates.
The principles would be applicable during the filling
period, defined as the time required to fill Glen
Canyon (elevation 3700), with a cutoff date of May 31,
1987, the date when the Hoover power
contracts expire. Provision was also made for earlier
termination if conditions warranted and called
for consultation with the States before such action.
During the filling period, uses of water below Hoover Dam,
other than power, will be satisfied,
including delivery of not more than 1.5 maf/yr to Mexico.
Minimum power head (elevation 3490 -
6.1 maf available surface storage) would be sought at Glen
Canyon at the earliest practicable time
without drawing Lake Mead below its rated head (elevation
1123 - 14.5 maf available surface
storage).
The partial closure of Glen Canyon Dam was accomplished
March 31, 1963, when computationally
the Hoover deficiencies began, at which time Lake Mead held
22.3 mat. This dropped to 15.4 maf at
the beginning of January 1964. Lake Powell was about 3410
(80 feet short of the minimum power
point of 3490). With a forecast of another poor runoff in
1964 the gates of Glen Canyon were
ordered opened on March 26, 1964 by the Secretary to
maintain elevation 1123 at Lake Mead,
despite Upper Basin requests that water be retained in Lake
Powell in order to start generation of
energy by August 1, 1964. However, 6 weeks after the gates
were opened; on May 11, 1964, the
Secretary announced the closure of the gates at Glen Canyon
and the modification of the 1962 Filling
Criteria to reduce by 40 feet, from elevation 1123 (rated
power head) to elevation 1083 (minimum
power pool), the water level below which Lake Mead would
not be drawn. This was conditioned on
the fact that, in addition to the allowance for
deficiencies in firm energy pursuant to the 1962 Filling
Criteria, the United States would replace impairments in
Hooves. Powerplant capacity and energy
which result from lowering Lake Mead below elevation 1123
by reason of' storage of water in Lake
Powell, and would also relieve the allottees of the costs
of extraordinary maintenance of the turbines
and generators resulting from such lowering. These costs
would be charged to the Upper Basin Fund
but were not subject to reimbursement as was the case for
deficiencies in firm energy as determined
pursuant to the 1962 Filling Criteria.
Minimum power operating level (6.1 maf at elevation 3490)
was achieved in Lake Powell on August
18, 1964. Energy generation began September 4, 1964. To
obtain this minimum power pool at Glen
Canyon Dam the flow at Lee Ferry was restricted to
2,520,000 acre-feet in water year 1963 and
2,427,000 acre-feet in water year 1964. Because of the
tight water situation, Secretary Udall also
directed Lower Basin water users, on May 16, 1964, to
reduce their water demands by 10 percent
for the period of July through December 1964. The
Metropolitan Water District of Southern
California was exempted from the 10 percent cutback. Also,
a suit by the Yuma Valley water users
to overturn the decision was unsuccessful.
The water surface elevation of Lake Mead dropped to a low
of 1088.1 in December 1964, but was
restored to rated power head elevation of 1123 on June 23,
1965.
The Upper Basin has repeatedly sought termination of the
Filling Criteria or relief from use of the
Upper Colorado River Basin Fund for payment for energy
deficiencies at Hoover Dam. This led to
Section 502 of the Colorado River Basin Project Act, which
provides for reimbursement to the
Upper Basin Fund for monies used therefrom and replaced
Additional Regulation No. 1.
During discussions on the formulation of the Operating
Criteria, Upper Basin efforts to terminate the
Filling Criteria were unsuccessful, as were other attempts
in 1975 and 1978.
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