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Pacific Northwest Region
Boise, Idaho
Media Contact:
David Walsh
(208) 378-5026

Released On: March 03, 2003

Reclamation on Schedule with Valve Replacement Project at Arrowrock Dam
Bureau of Reclamation engineers and construction crews are on schedule with a $15 million construction project at Arrowrock Dam. The construction is to replace the original ensign valves installed in the dam back in 1915 with more efficient clamshell gates designed to extend the life of the 88-year-old structure.

This is the second year of the three-year construction project at Arrowrock Dam, located on main stem of the Boise River about 17 miles upstream from Boise, Idaho.

Crews have been busy installing new clamshell gates on the downstream face of the dam.

"As of last week, eight of the 10 mid-level clamshell gates at Arrowrock Dam have been installed," said Don Rosbaugh, Bureau of Reclamation Resident Engineer. "The Arrowrock Dam Valve Replacement Project will modernize water operations and ensure a longer and more productive operational life for the dam."

When the 10 new clamshell gates come on-line in July 2004, they will be used exclusively for water releases through Arrowrock Dam.

Mounted on the downstream side, the clamshell gates have stainless steel control gates and are operated hydraulically. Named for a popular crustacean, the new gates open and close like two halves of a clamshell.

Crews from Record Steel & Construction, Inc., used a 400-foot boom crane, located near the base of Arrowrock Dam, to lift each 26,000 pound water release gate.

"Installation of the valve works has been technically demanding. Crews have been working feverishly all winter to finish the work while Lucky Peak reservoir water levels are extremely low.," said Rosbaugh. "We'll have the major construction work on the downstream side complete just before the irrigation and recreation season begins at Lucky Peak in late April."

According to Rosbaugh, the clamshell gates will be tested in the coming months and by late April the construction crews will knock off for the summer irrigation season.

Season three will resume in September with the removal of the old ensign valves on the upstream side of Arrowrock Dam. Reclamation will be providing public updates, both through the media and on our website (http://www.pn.usbr.gov/project), of the season three construction schedule this summer.

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Reclamation is the largest wholesale water supplier and the second largest producer of hydroelectric power in the United States, with operations and facilities in the 17 Western States. Its facilities also provide substantial flood control, recreation, and fish and wildlife benefits. Visit our website at www.usbr.gov.