[Federal Register Volume 62, Number 41 (Monday, March 3, 1997)]
[Notices]
[Pages 9447-9448]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-5144]
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DEPARTMENT OF THE INTERIOR
Bureau of Reclamation
Operating Criteria and 1997 Annual Plan of Operations for Glen
Canyon Dam
AGENCY: Bureau of Reclamation, Interior.
ACTION: Adoption of operating criteria and 1997 annual plan of
operations.
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SUMMARY: Pursuant to the Grand Canyon Protection Act of 1992, the
Bureau of Reclamation (Reclamation) is required to prepare formal
Operating Criteria and an Annual Plan of Operations following
completion of an audit by the General Accounting Office (GAO) and the
Record of Decision (ROD) on the Operation of Glen Canyon Dam. The GAO
audit was completed on October 2. 1996, and the Glen Canyon Dam
Operation ROD was signed on October 9, 1996. Draft copies of the
proposed Operating Criteria and the 1997 Annual Plan of Operations were
distributed to Governors of the Colorado River Basin States, the Upper
Colorado River Commission, appropriate Federal agencies, Indian Tribes,
representatives of academic and scientific communities, environmental
organizations, the recreation industry, contractors for the purchase of
federal power produced at Glen Canyon Dam, and others interested in
Colorado River operations.
FOR FURTHER INFORMATION CONTACT: Mr. Bruce Moore, Bureau of
Reclamation, 125 South State Street, Room 6107, Salt Lake City, Utah
84138-1102; telephone: 801-524-3702.
SUPPLEMENTARY INFORMATION: The Operating Criteria specify the
requirements for an annual report of operations under the Grand Canyon
Protection Act, a periodic review of Operating Criteria, and details
regarding operational constraints. These constraints include maximum,
minimum, and daily fluctuation flow rates, maximum ramp rates,
emergency exception criteria, flood frequency reduction measures, habit
maintenance flows, and beach/habitat building flows.
The 1997 Annual Plan of Operations reflects the operation of Glen
Canyon Dam consistent with the Operating Criteria. Monthly releases are
expected to vary between 600,000 acre-feet and 1,500,000 acre-feet and
daily fluctuations will likely vary between 6,000 cfs/day and 8,000
cfs/day depending on monthly release volumes. The revised maximum daily
flow rate of 25,000 cfs and the maximum upramp rate of 4,000 cfs/hr.
will be placed into effect following signing of these documents by the
Secretary of the Interior. The following paragraphs contain the final
text of the Operating Criteria and the 1997 Plan of Operations for Glen
Canyon Dam.
Operating Criteria: These Operating Criteria are promulgated
according to section 1804 of Public Law 102-575, the Grand Canyon
Protection Act of 1992. They are to control the operation of Glen
Canyon Dam, constructed under the authority of the Colorado River
Storage Project Act. These Operating Criteria are separate and apart
from the Criteria for Coordinated Long-Range Operation of Colorado
River Reservoirs prepared according to the Colorado River Basin Project
Act of 1968.
1. Annual Report: As required in the Grand Canyon Protection Act, a
report shall be prepared and submitted to Congress annually. This
report will describe the operation of Glen Canyon Dam for the preceding
water year and the expected operation for the upcoming water year. The
annual plan of operations shall include such detailed rules and
quantities as are required by the Operating Criteria contained herein.
It shall provide a detailed explanation of the expected hydrologic
conditions for
[[Page 9448]]
the Colorado River immediately below Glen Canyon Dam.
2. Review of Criteria: The Secretary of the Interior shall review
these Operating Criteria as the result of actual operating experiences
to determine if the Operating Criteria should be modified to better
accomplish the purposes of the Grand Canyon Protection Act. Such a
review shall be made at least every 5 years in consultation with the
appropriate Federal agencies, Governors of the Colorado River Basin
States, Indian Tribes, representatives of academic and scientific
communities, environmental organizations, the recreation industry and
contractors for the purchase of Federal power produced at Glen Canyon
Dam.
3. Specific Operational Constraints: The plan of operations will
follow the description of the preferred alternative (Modified Low
Fluctuating Flow) in the Operation of Glen Canyon Dam Final
Environmental Impact Statement and its Record of Decision. The specific
criteria are as follows:
Minimum Releases--8,000 cfs between 7 a.m. and 7 p.m. and 5,000 cfs
at night.
Maximum Releases--25,000 cfs. Several circumstances warrant
exception to this restriction. These are the Beach/Habitat Building
Flows and the Habitat Maintenance Flows (both described below) and the
release of large volumes of water to avoid spills or floodflow releases
from Glen Canyon Dam. These latter releases would most likely result
from high snowmelt runoff into Lake Powell; if such high releases above
25,000 cfs are required, they shall be made at constant daily flow
rates.
Allowable Daily Flow Fluctuations--5,000 cfs/24 hours for monthly
release volumes less than 600,000 acre feet; 6,000 cfs/24 hours for
monthly release volumes of 600,000 to 800,000 acre feet; and 8,000 cfs/
24 hours for monthly release volumes over 800,000 acre feet.
Maximum Ramp Rates--4,000 cfs/hour when increasing, and 1,500 cfs/
hour when decreasing.
Emergency Exception Criteria--Normal powerplant operations will be
altered temporarily to respond to emergencies. These changes in
operations typically would be of short duration (usually less than 4
hours) and would be the result of emergencies at the dam or within the
interconnected electrical system. Examples of system emergencies
include:
Insufficient generating capacity.
Transmission system; overload, voltage control, and
frequency.
System restoration.
Humanitarian situations (Search and rescue).
Flood Frequency Reduction Measures--The frequency of unanticipated
flood flows in excess of 45,000 cfs will be reduced to no more than 1
year in 100 years as a long-term average. This will be accomplished
initially through the Annual Operating Plan process and eventually by
raising the height of the spillway gates at Glen Canyon Dam 4.5 feet.
Habitat Maintenance Flows--Habitat maintenance flows are high,
steady releases within powerplant capacity (33.200 cfs) not to exceed
14 days in March, although other months will be considered under the
Adaptive Management Program. Actual powerplant release capacity may be
less 33,200 cfs under low reservoir conditions. These flows will not be
scheduled when projected storage in Lake Powell on January 1 is greater
than 19,000,000 acre feet, and typically would occur when annual
releases are at or near the minimum objective release of 8,230,000
acre-feet. Habitat maintenance flows differ from beach/habitat-building
flows because they will be within powerplant capacity, and will occur
nearly every year when the reservoir is low.
Beach/Habitat-Building Flows--These controlled floods will occur as
described in the EIS (steady flow not to exceed 45,000 cfs, duration
not to exceed 14 days, up-ramp rates not to exceed 4,000 cfs/hours, and
down-ramp rates not to exceed 1,500 cfs/hour) except instead of
conducting them in years in which Lake Powell storage is low on January
1, they will be accomplished by utilizing reservoir releases in excess
of powerplant capacity required for dam safety purposes. Such releases
are consistent with the 1956 Colorado River Storage Project Act, the
1968 Colorado River Basin Project Act, and the 1992 Grand Canyon
Protection Act.
1997 Annual Plan of Operations: Under the most probable inflow
conditions in water year 1997, Glen Canyon Dam is expected to release
about 14.1 million acre-feet through the Grand Canyon to Lake Mead.
This is about 5.9 million acre-feet greater than the minimum objective
release and is the result of high snowpack conditions throughout the
Colorado River basin. Lake Powell is expected to fill in July.
Monthly release volumes from Glen Canyon Dam during 1997 are
expected to range from 600,000 acre-feet to 1,500,000 acre-feet.
Projected daily allowable fluctuations therefore will be 6,000 cfs or
8,000 cfs (see criteria). With the projected monthly release volumes,
it is likely that peak daily releases will exceed 20,000 cfs during the
months of February through July, when monthly release volumes are at
their highest for the year. Minimum releases of 5,000 cfs at night and
8,000 cfs during the day and ramping rates of 4,000 cfs/hr increasing
and 1,500 cfs/hr decreasing will be followed. All of the above is
outlined in the Record of Decision implementing the preferred
alternative of the Glen Canyon Dam Environmental Impact Statement.
With current projected monthly release volumes, daily releases will
exceed 20,000 cfs during the months of February through July, when
monthly release volumes are at their highest for the year. Releases
above 25,000 cfs will be made as steady flows. Since there are concerns
for possible modifications of the environmental restoration in the
Grand Canyon accomplished last year with the beach/habitat building
flow, monitoring of the impacts of this spring's releases will be an
important objective of the Grand Canyon Monitoring and Research Center
and may result in fluctuating flows to aid in this effort.
Every measure will be taken to prevent a powerplant bypass this
spring in order to preserve the environmental enhancement accomplished
by the beach/habitat building flow test in April 1996. Water year 1997
had a January 1, 1997, Lake Powell storage content greater than 19
million acre-feet; therefore a beach/habitat maintenance flow of
powerplant capacity is not planned.
This plan in prepared in conformance with Section 1804(c)(1)(A) of
the GCPA. Any changes to the plan would require reconsultation in
accordance with this Act.
The draft Operating Criteria and the 1997 Annual Plan of Operations
were discussed at a consultation meeting held on November 21, 1996,
with the Transition Work Group, which includes many of the same people
who received draft copies.
Dated: February 14, 1997.
Eluid L. Martinez,
Commissioner, Bureau of Reclamation.
[FR Doc. 97-5144 Filed 2-28-97; 8:45 am]
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