Clues to the future of Anchorage’s water supply locked away in ice
Anchorage is one of the few North American cities that depend on a glacier for most of their drinking water. The Eklutna glacier also provides some of the city’s electricity, through hydro power. So a team of researchers is working to answer a very important question: How long will the glacier’s water supply last?
To get that answer, those researchers have to shovel a lot of snow. “It gets to be the consistency of really strong Styrofoam once you get down, maybe six or eight feet,” glaciologist Louis Sass says as he flings pristine snow out of a growing hole in the glacier.
It may be a tough job, but it comes with a stunning view. The white glacier sprawls out around Sass, who has spent years researching the Eklutna glacier. It looks a little like a huge lake, covered by a giant, fluffy marshmallow and rimmed with sharp peaks.
Mike Loso, who leads the project, says workers at the water-treatment plant brag that they have the best job in the world. “If you look around, you understand why,” Loso says. “The guys here just have to turn this into drinking water; they just have to figure out how not to screw it up.”
The Anchorage utilities want to know how much meltwater they can expect the glacier to feed into the reservoir they draw from in the years ahead. So six years ago, Loso, an earth sciences professor at Alaska Pacific University, started bringing his students into the field to study the problem.
They spend three weeks each May camping on the glacier, skiing to several research plots to gather data. On a recent afternoon, that means weighing cake-sized pieces of snow sliced from the wall of the snow pit.
A student slides the snow into a plastic bag to weigh it on a portable scale. The precise measurements will help the team determine how much snow accumulated on the glacier last winter. The students are learning how to gather data in the field and stay safe on the glacier.
Haley Williams, a college junior, says she wants to be a scientist.
“I have a fascination with glaciers and volcanoes, and I’m trying to figure out which I like better,” she said. “So I figured I’d come out here, see if I have what it takes to be a glaciologist.”
The students determined that the Eklutna glacier has been shrinking rapidly since the 1950s. The Anchorage utilities are in good shape now because the glacier is actually supplying extra water as it melts, and that should last for at least the next few decades.
Loso can’t predict precisely when the water will start to slow, but he says it’s something Anchorage and its nearly 300,000 residents should think about.
“Does that mean we don’t have electricity, and no water comes out of the tap? No,” he says. “But it does mean that an exceptional source of super clean, really cheap water is going to have to be augmented by what are likely to be more expensive sources of water and electricity.”
Loso says that hit to Anchorage residents’ pocketbooks will seep in slowly, over several decades.
As Loso’s team prepares to leave the site, they insert a 20-foot steel stake in the glacier. When they come back later this fall, they’ll be able to calculate how much snow has melted by measuring how much of the stake is exposed. Loso says he personally would like a hot summer, but he knows that’s not what’s best for the Eklutna glacier.