Efforts to achieve 95 percent survival of young salmon and steelhead passing through the Priest Rapids Project have resulted in the utility spilling an average of 50 percent of the river flow during juvenile salmon migration. Grant County PUD spills more water annually to enhance fish passage than any other dam operator in the region. In recent years, the number of salmon and steelhead returning to spawn has reached record levels, in part due to the investments the hydropower system has made. The lifecycle of these species is complex, and survival is affected by many factors. Many scientists credit improved ocean conditions for the record salmon and steelhead returns in recent years.
One of Grant PUD’s recent innovative efforts monitors spill effectiveness through the utilization of a helicopter to transport young Chinook salmon above and below the dams. The salmon are tagged with miniature computer chips that emit a radio frequency that allows them to be monitored as they pass through the project.