Water to Be Diverted From 2 Dams for Sake of Salmon

The Army Corps of Engineers on Tuesday approved an emergency plan to spill extra water over the Snake and Columbia river dams in hopes of boosting salmon survival despite concerns that it could do more harm than good.

The Bonneville Power Administration was prepared to start “wheeling power” from other sources at midnight to make up for the loss of generating capacity from diverting more water to spillways and away from turbines, corps spokesman Orel Dugger said in Portland, Ore.

The corps was developing a program to monitor whether the spills kill fish because the extra water going over spillways puts more nitrogen into the river.

The dissolved nitrogen gas can kill fish in much the same way that a deep-sea diver gets the bends from surfacing too quickly. Scientists are divided on whether it is safe.

Ordered by a federal judge to do more to help salmon survive passage over the Columbia Basin dams, the National Marine Fisheries Service proposed the bold step. It is aimed particularly at helping Snake River runs of sockeye, which are endangered, and chinook, which are threatened.

Hydroelectric dams are blamed for killing as many as 90% of the salmon smolts coming out of the Snake River. The idea is to push more salmon smolts over spillways.

Less water would be available to go through hydroelectric turbines as a result, and the Bonneville Power Administration would have to buy electricity from other sources.