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Execs Support Removable Spillway Weir at Ice Harbor by Mike O'Bryant Columbia Basin Bulletin - December 19, 2003

NOAA Fisheries and the Bonneville Power Administration executives "strongly support" continuing to design the installation of a removable spillway weir (RSW) at Ice Harbor Dam on the lower Snake River.

The federal executives were briefed today (Dec. 18) on the design of the Lower Granite Dam removable spillway weir, along with the results of biological research studying the effectiveness of the device for fish passage and the economic benefits of the RSW for BPA operations, said Witt Anderson of the U.S. Army Corps of Engineers.

He told the CBB that Bob Lohn, regional administrator for NOAA Fisheries, and Steve Wright, administrator of BPA, after listening to the closed-door briefing, strongly supported the Corps' efforts to continue to design the RSW. That process already is about 60 percent complete and is expected to yield a contract for construction by late January or early February 2004.

The Corps installed an RSW at Lower Granite Dam in early 2002 to improve fish passage and survival at the dam. Early results showed that both passage and survival improved and that it was accomplished with less spill at the dam. That also lowers the cost of fish passage for the hydroelectric system. Seeking a lower cost and more effective way to spill water to improve fish survival, BPA in October 2002 proposed to the System Configuration Team that it accelerate the installation of RSWs at Ice Harbor and Lower Monumental dams and to install the devices as soon as possible.

The thing is, Anderson said, the Corps funding for the project is still uncertain.

"We still don't have a work allowance yet and don't know if we'll have to rely on 'slippage' savings as we have in the past," he said. However, if that works out, he said that BPA and NOAA Fisheries strongly support moving ahead.

Preliminary results of an evaluation of the RSW at Lower Granite Dam show that survival probability rises from 93.1 percent with spill to 98 percent with the RSW and that survival is more consistent over the entire spill season with the RSW.

Given that success, at an Implementation Team meeting Dec. 4, the Corps, BPA and NOAA Fisheries said they had concluded that an RSW would also benefit passage at Ice Harbor Dam, while providing BPA a financial advantage due to less spill. BPA had estimated that savings from using the RSW at Ice Harbor Dam could be as high as $22 million a year due to reduced spill levels. Design work on an RSW for Ice Harbor Dam is already under way.

SCT had considered three alternatives for RSW construction, but NOAA Fisheries promoted installing an RSW at Ice Harbor Dam by the 2005 spring spill season. The NOAA plan also includes installation of RSWs at Lower Monumental in 2006 and at Little Goose in 2007. As is suggested by the federal executive's approval today, the Corps is on track to install the Ice Harbor RSW if the region reaches a final decision on the project by January 2004.

Related Sites:

Federal Executives: www.salmonrecovery.gov
Implementation Team: www.nwr.noaa.gov/1hydrop/hydroweb/rif.htm