Cantwell Chairs Hearing on Impact of Climate Change on Water Supply in the West

Declining snowpack, changing weather patterns could leave municipalities, agriculture, and dams with less water, harm endangered salmon runs

WASHINGTON, DC – Wednesday, U.S. Senator Maria Cantwell (D-WA) chaired a Senate Water and Power Subcommittee hearing on the impact of climate change on water supplies in western states. At the hearing, Cantwell looked into the effect of declining snowpack, changing precipitation patterns, and reduced stream flows on farmers, municipalities, hydropower, and the environment.

"Northwest glaciers are melting, our annual snowpack is shrinking, and seasonal runoff is starting earlier, posing a major threat to the economic vitality of our region," said Cantwell, a member of the Senate Energy and Natural Resources Committee. "These changes will force us to adapt how we manage irrigation and agriculture, our hydropower system, salmon recovery, municipal water supplies, and flood control. We need a real strategy to keep our region strong and respond to any impacts we observe."

During the last 200 years, humans have released 1.5 trillion tons of carbon dioxide into the atmosphere, and human-caused emissions have increased the atmospheric carbon dioxide concentration by 35 percent. According to the Washington State Department of Ecology, snowpack in the North Cascades has declined at nearly 75 percent of sites studied, and spring runoff occurs earlier each year across the state, including in the Columbia River Basin. As a result of decreasing water flows, University of Washington researchers predict a 5 percent revenue loss, totaling $166 million per year, for the Columbia River hydrosystem.

The cost of offsetting the decline in guaranteed water for the City of Seattle alone could rise above $8 million per year by 2020, and $16 million by 2040. Other communities in the state could face similar problems.

"As snowpack declines and runoff occurs earlier in the season, less water will be available during the dry summer months, not just for cities, agriculture, and irrigation, but also for hydropower, fish habitat, and recreation," Cantwell added.

More frequent droughts and a disruption in steady and predictable water supplies may lead to increased crop losses totaling in the tens of millions of dollars. During the 2001 drought, for example, an extremely low Pacific Northwest water table cost the region $750 million.

Warmer temperatures could also bring more severe storms, which can lead to flooding, and reduced stream flows could harm already endangered salmon runs. Changing conditions have also led to an increase in wildfires, and the cost of fighting these fires in Washington state could increase by 50 percent to an average of $75 million per year by 2020. The average number of large wildfires in the state has risen from six per year in the 1970s to 21 per year during the past few fire seasons.

At Tuesday’s hearing by the Senate Energy and Natural Resources Subcommittee on Water and Power, Cantwell heard testimony from Dr. Philip Mote, a climatologist from the University of Washington who has documented declining glaciers in the Cascades. She also heard testimony from Brad Udall, Director of the Western Water Assessment Project at the University of Colorado, Dr. Christopher Milly, a research hydrologist with the U.S. Geological Survey, Patrick O’Toole, President of the Family Farm Alliance, and Tim Culbertson, General Manager of Grant County PUD representing the National Hydropower Association. Under Mr. Culbertson’s direction, Grant County PUD is leading the way in water management on the Columbia River for hydropower, irrigation, and salmon recovery.