Shrinking Glaciers Could Squeeze Washington's Water Supply

Transcript

ROBERT SIEGEL, HOST:

And while upstate New Yorkers may be facing more snow than they've ever seen, Washington state is watching its glaciers recede. It has more glaciers than any other state in the lower 48. And their shrinking will likely affect drinking water supplies, hydropower and salmon in the Northwest. Ashley Ahearn reports from member station KUOW in Seattle.

ASHLEY AHEARN, BYLINE: More than 375 glaciers feed Washington's Skagit River. Jon Riedel is hiking up to one of them on the slopes of Mount Baker.

JON RIEDEL: We're headed up along Rocky and Sulfur creeks, toward the terminus of Easton Glacier.

AHEARN: Riedel's been studying glaciers with the National Park Service for more than 30 years. The sheer number of glaciers in this region sets Washington apart from the rest of the country. But with climate change, it also makes the state uniquely vulnerable. Riedel pauses just shy of 40,000 feet elevation, in the middle of a field of boulders - no glacier in sight.

RIEDEL: If you were here in 1907, you'd be looking right at the terminus of the glacier.

AHEARN: And now where is it?

RIEDEL: Well, now it's around the corner. You can't see it.

AHEARN: Old photographs show this whole valley covered in ice. But that's changing. Glaciers in the North Cascades have shrunk by 50 percent over the last century. Riedel says throughout history, glaciers have advanced and retreated over these mountains hundreds of times. But now it's different.

RIEDEL: The glaciers now seem to have melted back up to positions they haven't been in for 4,000 years or more. So we've kind of gone beyond that - I think that natural scale of variability.

AHEARN: Glaciers provide billions of gallons of water to rivers in the Northwest. Glacial melt flows out of the mountains at critical points in the year, when rivers are running low at the end of the dry summer months. Perhaps no one understands that better than the people in charge of operating dams for hydropower.

CRYSTAL RAYMOND: My name is Crystal Raymond, and we are at the base of Ross Hydroelectric projects.

AHEARN: Ross Dam towers 450 feet above us as we motor up Diablo Lake in Washington's North Cascades. Raymond worked for Seattle City Light. The utility operates three dams on the Skagit river that provide about a quarter of the power for the city of Seattle.

RAYMOND: We are unique. There are not too many dams that operate in a place where some of the runoff coming into the project is coming from glaciers.

AHEARN: At the hottest, driest times of year, glaciers are the biggest source of water for some of the streams that feed this hydropower facility. It's Raymond's job to figure out what to do when the glaciers are gone. She says Seattle City Light will need to change how it stores water above the dams. Helping customers cut back on energy use is also going to be key. Summer hydropower production in Washington is expected to drop by roughly 15 percent in the next 25 years or so. But Raymond is an optimist.

RAYMOND: We know enough now to start getting prepared. And with time we'll know more, but the sooner we start, the more likely we are to reduce the impacts.

AHEARN: Several miles downriver from Ross Dam, Erin Lowery scans the clear water for salmon nests - or redds, as they're called.

ERIN LOWERY: Right there you can see the dark shape - right there in the water. So it's sort of near the edge of the redd there. So that's a Chinook salmon sitting on the redd.

AHEARN: Lowery is a fish biologist for Seattle City Light. The utility is required to manage its dams to protect spawning fish. Too much water released from the dams, and the nests will get washed away. Too little, and they'll be left high and dry. This mama Chinook's tail is ragged and white where she's used it to shovel away the gravelly riverbed to make room to lay her eggs. Now, she's guarding them.

LOWERY: She'll sit on that redd and defend it until she loses energy and dies.

AHEARN: And Erin Lowery will do his best to defend her. He and his team record the location of the nest and how deep the water is there. Glacial melt flows into warming rivers like dropping an ice cube in a glass of lemonade. No glaciers means warmer rivers. And that's bad news for salmon.

LOWERY: You start to affect not only the fish themselves, but it can have a negative effect on their eggs.

AHEARN: Lowery says it hasn't come down to a choice between fish or power yet. But he loses sleep thinking about that possibility someday.

LOWERY: As we move forward, I mean, it's going to be a pretty hard look at how we manage flows in the river with the changing climate, with a reduction in glaciers and snow pack.

AHEARN: Because people are moving to the Puget Sound constantly, and they're all going to need electricity. For NPR News, I'm Ashley Ahearn on the Skagit River. Transcript provided by NPR, Copyright NPR.