Steady rainfall, a robust snowpack and rising rivers are the reasons many of the region's wind farms and fossil fuel generators were shut down for five hours on Wednesday and could be turned off again tonight.
The Bonneville Power Administration shut down much of the region's power generation, with the exception of hydroelectric drams that are running at full capacity because of the heavy spring runoff. Depending on how quickly the water eventually flows to the Pacific Ocean, the region is expected to be powered primarily through hydropower for at least a few weeks.
The volume of runoff is being called the greatest in more than a decade, and that's causing another problem: It subjects fish to dangerous levels of nitrogen gas bubbles in the churning water.
The Bonneville Power Administration markets about a third of the region's power, from 31 dams and from a nuclear plant on the Hanford nuclear reservation in eastern Washington.