Juneau anxiously holds its breath as glacial floodwaters rise

WBUR

Published August 13, 2026 at 10:58 AM CDT

Glacial floodwaters on the Mendenhall River have put thousands of homes at risk in Juneau, Alaska.

Emergency managers have urged people living near the river to evacuate as a glacial lake outburst flood continues to build toward its peak Thursday afternoon.

“There are more pumps in Juneau, Alaska, than any place in the United States,” said U.S. Army Corps of Engineers Brig. Gen. Clete Goetz, describing the level of effort and infrastructure in place to combat the rising water.

Barriers along the Mendenhall River erected to protect the city from glacial lake outburst floods. (Peter O'Dowd/Here & Now)

The river that runs through Alaska’s capital has flooded annually since 2011 because of a basin that has formed by retreating ice in the mountains above town. As melting ice water in the basin builds up behind the Mendenhall Glacier, the pressure increases and eventually releases downstream.

“The amount of water in the basin, it’s a lot, 17 billion gallons,” said Aaron Jacobs, a hydrologist for the National Weather Service. “It’s the warming environment that’s melted these glaciers.”

The floods have become more intense in recent years.

In 2023, a home was swept into the raging river, and a year later, about 300 homes were inundated. In 2025, officials installed military-style Hesco barriers, which were mostly effective at holding back the water.

This year, the U.S Army Corps of Engineers extended the barriers higher and installed more of them along the river. Forty-three high-capacity pumps were installed to remove any water that gets past the barriers. Heavy rocks were placed on the riverbanks to prevent erosion.

Hours before this years flood began, John Lohrey shows how high the flood waters reached at his Juneau home in 2024. (Peter O'Dowd/Here & Now)

“We are feeling more prepared than ever,” said City Manager Katie Koester. “But if we do have a breach of the Hesco barriers, it will be a flash-flood scenario, so we are urging people to evacuate.”

Diane Lohrey evacuated her young children, but the adults and teenagers at her house stayed home.

“I’m anxious,” said Lohrey, whose home was badly damaged by the flood in 2024. “Am I being foolish to think all the work that was done will protect us? Or are we going to get hit?”

This article was originally published on WBUR.org.