[Federal Register Volume 74, Number 173 (Wednesday, September 9, 2009)]
[Notices]
[Pages 46452-46453]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-21723]
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DEPARTMENT OF THE INTERIOR
Bureau of Reclamation
B.F. Sisk Dam Corrective Action Project, Merced County, CA
AGENCY: Bureau of Reclamation, Interior.
ACTION: Notice of intent to prepare an environmental impact statement/
environmental impact report (EIS/EIR) and notice of public scoping
meeting.
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SUMMARY: The Bureau of Reclamation (Reclamation), as the lead federal
agency, and the State of California Department of Water Resources
(DWR), as the lead state agency, are preparing a joint EIS/EIR,
pursuant to the National Environmental Policy Act (NEPA) and the
California Environmental Quality Act (CEQA), respectively, for the B.F.
Sisk Dam Corrective Action Project (proposed action). The purpose of
the proposed action is to improve public safety by modifying B.F. Sisk
Dam to mitigate potential safety concerns identified in the ongoing
Corrective Action Study (CAS). Engineering and economic studies are
currently being conducted by Reclamation and DWR to determine
corrective action alternatives (modifications) that would address
potential safety concerns related to structure stability under extreme
seismic loading conditions. A scoping meeting will be held to obtain
input on alternatives, concerns, and issues to be addressed in the EIS/
EIR. Written comments may also be sent, emailed, or faxed.
DATES: A public scoping meeting will be held on Wednesday, September
23, 2009, from 3 p.m. to 7 p.m. at the San Luis Recreation Area,
Gustine, CA.
ADDRESSES: The scoping meeting will be held in the conference room at
the California Department of Parks and Recreation Four Rivers Sector
Office, 31426 Gonzaga Road, Gustine, CA 95322.
Written comments on the scope of the EIS/EIR should be sent by
close of business on Tuesday, October 6, 2009 to: Ms. Patti Clinton,
Bureau of Reclamation, South-Central California
[[Page 46453]]
Area Office, 1243 N Street, Fresno, CA 93721, or via e-mail to
[email protected], or by fax to 559-487-5397.
FOR FURTHER INFORMATION CONTACT: Ms. Patti Clinton, Bureau of
Reclamation, South-Central California Area Office at the above address
or e-mail address, or by phone at 559-487-5127.
SUPPLEMENTARY INFORMATION: B.F. Sisk Dam is a 300-foot-high compacted
earthfill embankment located on the west side of California's Central
Valley approximately 12 miles west of Los Banos, California. The dam is
more than 3\1/2\ miles long and impounds San Luis Reservoir, which has
a total capacity of over 2 million acre-feet. The dam was built between
1963 and 1967 to provide supplemental irrigation water storage for the
Federal Central Valley Project and municipal and industrial water for
the California State Water Project. Water is lifted into the reservoir
for storage by the Gianelli Pumping-Generating Plant from the
California Aqueduct and from the Delta-Mendota Canal via O'Neill
Forebay. B.F. Sisk Dam (also known as San Luis Dam) is owned by
Reclamation and operated by DWR. Of the total reservoir storage
capacity, 55 percent is allotted to State uses and 45 percent is
allotted to the Federal uses.
The dam and reservoir are located in an area of high potential for
severe earthquake loading from identified active faults, primarily the
Ortigalita Fault that crosses the reservoir. In the early 1980s,
Reclamation conducted an extensive investigation of the seismic safety
of B.F. Sisk Dam. The investigation included drilling holes to sample
the soils and test their density in place, laboratory testing of the
samples, and geophysical tests. Using the methods available at the
time, the amount of deformation that would occur under severe shaking
was predicted to be small, and the conclusion was that the dam had no
safety deficiencies.
By 2005, the state of the art in seismic analysis of dams had
changed significantly, and additional dam safety investigations were
performed. These included a reevaluation of the Ortigalita Fault,
development of a new understanding of the behavior of the soil
materials (including embankment fill) under earthquake loading, and
development of new computer-based analysis methods for predicting the
behavior of the dam under various loadings. With the updated methods
and earthquake loadings, the dam crest was predicted to settle, during
the most severe earthquakes, resulting in the height of the dam crest
being at the maximum water level in the reservoir.
While the current state of the art of analysis still involves
uncertainties and does not permit precise calculation of the amount of
settlement that would occur, it is possible (although not likely) that
the embankment deformation would exceed the available freeboard,
resulting in the reservoir overtopping the embankment and eroding a
breach of the dam. Even without overtopping, it is possible that water
flowing through cracks in the dam embankment could erode a breach as
well.
Reclamation is taking the lead on the CAS. DWR is an active
participant and has participated in the Risk Analysis, has reviewed
technical documents, and is participating in other CAS activities.
Scoping
Scoping is an open process that assists agencies in determining the
scope of the EIS and in identifying potentially significant issues
related to the proposed action. Scoping also provides an opportunity to
identify alternatives to the proposed action and possible mitigation
measures. All interested persons, organizations, and agencies wishing
to provide comments, suggestions, or relevant information on the
proposed action may do so by sending input by regular mail to
Reclamation at the above address; attending and providing comments at
the public scoping meeting, or by sending e-mail to the above e-mail
address.
Special Assistance for Public Scoping Meeting
If special assistance is required at the public hearings, please
contact Ms. Lynnette Wirth at 916-978-5102, or via e-mail at
[email protected]. Please notify Ms. Wirth as far in advance as possible
to enable Reclamation to secure the needed services. If a request
cannot be honored, the requestor will be notified. A telephone device
for the hearing impaired (TDD) is available at 916-978-5608.
Public Disclosure
Before including your name, address, phone number, e-mail address,
or other personal identifying information in your comment, you should
be aware that your entire comment--including your personal identifying
information--may be made publicly available at any time. While you can
ask us in your comment to withhold your personal identifying
information from public review, we cannot guarantee that we will be
able to do so.
Dated: July 2, 2009.
Anastasia T. Leigh,
Acting Regional Environmental Officer, Mid-Pacific Region.
[FR Doc. E9-21723 Filed 9-8-09; 8:45 am]
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