Managing Pacific Northwest dams for a changing climate

Civil engineers at the University of Washington and the U.S. Army Corps of Engineers’ Seattle office have taken a first look at how dams in the Columbia River basin, the nation’s largest hydropower system, could be managed for a different climate.

They developed a new technique to determine when to empty reservoirs in the winter for flood control and when to refill them in the spring to provide storage for the coming year. Computer simulations showed that switching to the new management system under a warmer future climate would lessen summer losses in hydropower due to climate change by about a quarter. It would also bolster flows for fish by filling reservoirs more reliably. At the same time the approach reduced the risk of flooding. The findings are published in the Journal of Water Resources Planning and Management.

“There are anticipated dramatic changes in the snowpack which ultimately will affect when the water comes into the Columbia’s reservoirs,” said co-author Alan Hamlet, a UW research assistant professor of civil and environmental engineering who works in the UW’s Climate Impacts Group. “We were trying to develop new tools and procedures for changing flood control operating rules in response to these changes in hydrology, and to test how well they work in practice.”

University of Washington News