[Federal Register: November 13, 1998 (Volume 63, Number 219)]
[Notices]               
[Page 63493]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13no98-108]

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DEPARTMENT OF THE INTERIOR

Bureau of Reclamation

 
Snake River Project, Arrowrock Dam Outlet Works Rehabilitation, 
Ada County, ID

AGENCY: Bureau of Reclamation, Interior.

ACTION: Notice of public scoping meetings.

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SUMMARY: Pursuant to section 102(2)(c) of the National Environmental 
Policy Act (NEPA) of 1969, as amended, the Department of the Interior, 
Bureau of Reclamation (Reclamation), has scheduled public meetings to 
collect scoping input for the proposed rehabilitation of outlet works 
at Arrowrock Reservoir. These meetings will assist in determining 
issues associated with the project that will be evaluated in the 
environmental impact statement. The primary purposes of the proposed 
action are to correct deficiencies in the values, reduce the difficulty 
and environmental impacts of future inspection and maintenance of 
Arrowrock Dam's outlet works, and to provide increased operational 
flexibility.

DATES: The scoping meetings will be held on December 14, 1998, from 1 
to 3 p.m. and from 7 to 9 p.m.
    Comments on the proposed project can be sent to the address below 
and will be accepted through December 28, 1998.

ADDRESSES: The scoping meetings will be held at The Natural Resources 
Center, 1387 South Vinnell Way, Boise, Idaho.
    Comments may be addressed to the Bureau of Reclamation, Snake River 
Area Office, 214 Broadway Avenue, Boise, Idaho 83702-7298.

FOR FURTHER INFORMATION CONTACT:
Steve Dunn, Natural Resource Specialist, at the above address or by 
telephone at (208) 334-9844.

SUPPLEMENTARY INFORMATION: A notice of intent to prepare an 
environmental impact statement was published in the Federal Register on 
October 20, 1998 (63 FR 56047, October 20, 1998).
    Arrowrock Dam is located on the Boise River, about 13 miles east of 
Boise, Idaho. Reclamation completed construction of the dam in 1915, 
and at that time it was the highest dam in the world. Arrowrock is one 
of three storage dams on the Boise River. Anderson Ranch Dam is located 
upstream of Arrowrock on the South Fork Boise River, and Lucky Peak 
Dam, constructed by the U.S. Army Corps of Engineers, is located on the 
Boise River downstream of Arrowrock and impounds water up against 
Arrowrock Dam when full. Arrowrock Reservoir is operated for irrigation 
and flood control in combination with Anderson Ranch and Lucky Peak 
Reservoirs. In general, water is stored in Arrowrock Reservoir during 
the winter and spring, according to predicted runoff and flood control 
requirements, and released through the summer for irrigation.
    The ensign valves controlling releases from Arrowrock Dam are the 
original valves installed in 1915. These valves have reached the end of 
their useful life, resulting in complex operational and maintenance 
concerns. Most of the valves have been damaged through prolonged use, 
and there is an increasing need for frequent inspection and repair. 
Three of the 10 ensign valves in the lower bank are no longer usable.
    The existing ensign valves also limit Arrowrock Dam's operational 
flexibility. The lower bank of ensign valves cannot be used under high 
water pressure when the reservoir is full. This reduces the dam's 
capability to release water for flood control operations in years with 
high runoff.
    Reclamation has developed a proposal to replace the 10 lower ensign 
valves with ``clamshell gates.'' The clamshell gates would allow 
releases at any reservoir level, providing more operational 
flexibility. The remaining upper row of 10 ensign valves and the sluice 
gates at the base of the dam could be abandoned, which would 
significantly reduce maintenance. The clamshell gates would be designed 
to allow inspection and maintenance without the need for dewatering.

    Dated: November 6, 1998.
Kenneth R. Pedde,
Acting Regional Director, Bureau of Reclamation.
[FR Doc. 98-30347 Filed 11-12-98; 8:45 am]
BILLING CODE 4310-94-M