Washington-based Puget Sound Energy has begun constructing a new powerhouse on northwest Washington’s Baker River to aid salmon runs while boosting the utility’s output of hydroelectric power, media reported.
The 30-MW power plant is the latest in a series of fish-enhancement initiatives undertaken by PSE as part of its 50-year federal operating license for the Baker River Hydroelectric Project. Among other things, the 2008 license requires a minimum downstream flow from PSE’s Lower Baker Dam of at least 1,000 cubic feet per second. The project’s previous license, issued in 1956, required flows of approximately 80 cubic feet per second to support upstream fish-passage facilities.
Besides increasing the minimum downstream flows passing through Lower Baker Dam, the new powerhouse’s 30-MW turbine will reduce the speed, or ‘ramping rate,’ at which PSE is able to take its power-generating operation offline. A slower ramping rate lessens the chances of juvenile salmon becoming stranded in side channels along the river as downstream water levels rise or fall. Resource agencies say the increase in downstream flows and a slower ramping rate will help salmon migration and spawning.
The larger, 79-MW turbine in PSE’s existing Lower Baker Dam powerhouse cannot operate efficiently under the new license’s required flow regimes. Instead of spilling water to meet the new requirements, PSE opted to build a second Lower Baker powerhouse immediately downriver that can take advantage of the flow directives in the new license.
The new powerhouse, scheduled for completion in late 2013, will raise the power capacity of PSE’s two Baker River dams from today’s 170 MW to 200 MW, enough peak output to serve 150,000 households.
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