Glacial outburst flooding in Juneau destroys homes

Two homes were destroyed in Juneau, Alaska, over the weekend due to glacial outburst flooding.

This type of flooding has been happening in Juneau since 2011. It occurs when thinning ice above the terminus of Mendenhall Glacier creates an ice dam in an area called Suicide Basin, which traps rain and meltwater. It fills up over the spring and summer before draining into Mendenhall Lake and Mendenhall River.

Usually, the glacial outburst flooding is gradual, but on Saturday, the lake and river levels began rising quickly. Juneau resident John Loverink told the Anchorage Daily News he had "no concerns" on Saturday morning, but by the afternoon the Mendenhall River was "four times as wide as it's ever been." Once the banks of the river eroded and he saw large clusters of trees start to fall into the water, Loverink quickly left his condo. He returned home on Sunday to see that one corner of his building was over a drop-off and the building next door was dangling in mid-air; both have been condemned by the city.

Several decks, deck chairs and structural timber floated by Juneau resident Bill Ballard as he watched the river rise on Saturday. "I was like, 'Oh my God, that's from houses upstream,'" he told the Daily News. His daughter lives in the same building as Loverink, and he helped get her out just before the fire department arrived. "You can't get in once they put up the tape," he said. "She's gonna lose a lot of stuff."

There was flooding reported "in areas that have not previously seen flooding before," the National Weather Service said, with the crest of Mendenhall Lake reaching 14.97 feet late Saturday, two feet over the last record set in 2016. "We didn't even think that this was possible," National Weather Service Juneau hydrologist Aaron Jacobs told ABC News.

There are thousands of cruise ship visitors who arrive in Juneau every day during the summer, with many including a trip to Mendenhall Glacier on their itinerary. City officials have already been dealing with the glacier receding — the glacier is melting faster because of rising temperatures, and by 2050, it might not be visible from the visitor center — and may need to add intense summer flooding to their list of concerns. "People come to Alaska to see what they consider to be a pristine environment and it's our responsibility to preserve that for residents and visitors," Alexandra Pierce, Juneau's tourism manager, told the Daily News.