Corps of Engineers Begins Spring Spill Operations with New Flexibility

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The U.S. Army Corps of Engineers will begin implementing its 2019 Fish Operations Plan at the four lower Snake River dams on Wednesday, and at the lower Columbia River dams on April 10.

The 2019 plan includes spill and transport operations for the spring and summer juvenile fish passage seasons at these dams, as specified in the NOAA Fisheries 2019 Columbia River System Biological Opinion.

Spring spill in 2019 will look different than previous years, as the Corps begins implementation of 24-hour flexible spill operations for the purpose of supporting downstream juvenile fish passage while also providing operational flexibility that allows federal power system benefits at these dams.

“This year’s operation allows us to take advantage of the off-peak, lower power demand hours to provide 16 hours of spill for juvenile fish passage, while reducing spill for up to eight hours during periods of greater power demand,” said Tim Dykstra, senior fish program manager for the Corps’ Northwestern Division.

Dykstra added that the Corps, the Bonneville Power Administration, the Bureau of Reclamation, the states of Oregon and Washington, and the Nez Perce Tribe reached a collaborative agreement to implement this new flexible spring spill operation. This operation will help the region learn whether spill for juvenile fish passage, up to the maximum total dissolved gas level allowable by the states, further improves the survival of juvenile salmon and steelhead and, over time, improves adult returns, while also keeping in balance costs in hydropower generation.

Key supporters of the agreement issued a statement at the time of the signing saying, “Collaboration is key to the new approach to Columbia River system management. Working together, the region’s states, tribes and federal agencies have developed an approach that demonstrates environmental stewardship and affordable sustainable energy are not mutually exclusive. We will use our expertise and best professional judgment to implement this operation. As with any new operation, successful implementation will require close coordination between the Corps and BPA. And since this operation involves spilling much more water at our dams for juvenile fish passage than in previous years, we will monitor the river system closely and adjust as necessary if we see any unintended consequences from the higher spill.”

The transition to summer spill begins on June 21 at lower Snake River dams and on June 16 at lower Columbia River dams. Summer spill for juvenile fish passage ends at all eight dams at midnight on Sept. 1.

The most recent water supply forecast for 2019 issued by the Northwest River Forecast Center for the Columbia River Basin (April–August) is 84 percent of normal as measured at The Dalles Dam and 92 percent of normal for the Snake River Basin, (April–July), as measured at Lower Granite Dam.

Spring snow melt will result in high water levels and high velocities below the dams.  River users, especially anglers, are reminded to be mindful of conditions and to always wear a personal flotation device when on or near the river.  Boaters should expect spill to create unusual currents, eddies and turbulent conditions, particularly immediately downstream of the dams and near navigation locks.

In addition to spill, the federal agencies will continue many other actions in the current biological opinion that benefit salmon and steelhead.

For more information on federal salmon and steelhead recovery efforts in the region, NOAA Fisheries’ 2019 Columbia River System Biological Opinion and the flexible spill agreement, visit www.salmonrecovery.gov.

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