How climate change could impact Anchorage's water source

Published: Oct. 12, 2019 at 3:43 PM AKDT
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Researchers at Alaska Pacific University have their eyes trained on the Eklutna Glacier, analyzing how it’s reacting to a changing climate.

In the first study of its kind of the Eklutna watershed, APU researchers looked at the soils that transport water from the Eklutna Glacier to Eklutna Lake. They say studies like these will help inform management of Anchorage’s primary water resource in a changing climate.

“We studied hydraulic conductivity, which is how fast water percolates through the soil,” APU Associate Professor of Geology and Earth Science Amanda King said. “This type of data can go into a hydrologic model to predict and characterize the flow of water through the basin.”

The research sounds really scientific, but King says it took simple tools … and a lot of hours.

"What we were doing was carrying around … it's basically a 5-gallon bucket with the bottom cut out. You put it into the soil, and then you dump water in, and you measure with a stopwatch how fast it drains into the soil," King said. "We just tried to measure it in as many places as we could, to try to characterize the whole area."

King emphasizes this is the first of hopefully many studies that will be used to develop a forecasting model for city managers to know how much water is draining into Eklutna Lake. The lake is a huge source of hydroelectric energy for the city, as well as its drinking source.

King says as the Eklutna Glacier melts, the importance of other water sources like snow melt and rain to replenish the lake grows. Scientists say surface water sources are diminishing in a warming climate -- and it's not just happening in Anchorage.

"Southcentral Alaska is seeing glaciers retreating everywhere," King said. This speaks to the importance of developing novel ways of saving and conserving water in areas like Anchorage, and much of the Kenai Peninsula, that rely solely on surface water sources like Eklutna Lake.

“The (Eklutna) glacier is the main source of water to the lake, however the glacier is shrinking. We know it retreated about a mile in 30 years,” King said. “Recent warming and hotter summers are contributing to faster-than-average rates of melting ... so we're seeing higher volumes of water coming from the glacier. I think there are estimates of an eight percent increase coming from the glacier ... so eventually that's not sustainable.

"I think it's safe to say that it's eventually going to disappear,” King continued. “But when that happens is hard to say."

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