Residents of Alaska capital Juneau are being urged to evacuate amid an “imminent threat of catastrophic flooding from a glacier lake outburst flood.”
Emergency management and National Weather Service officials said surge flooding from the Mendenhall River could begin to crest around 2 p.m. local time Wednesday.
The city installed 2 miles worth of emergency flood barriers just last month, but the water from the Mendenhall Glacier and its counterpart, dubbed Suicide Basin, could threaten most of Juneau’s 32,000 full-time residents.
Gov. Mike Dunleavy issued a preemptive disaster declaration, following damaging “glacial outbursts” in both 2023 and 2024.
Last year, the glacier released nearly 15 billion gallons of water from an upstream basin of rainwater and snowmelt, unleashing destructive flooding in Juneau that impacted more than 100 homes.
Forecasters think this year’s water levels could surpass last year’s record of 16 feet. By noon on Tuesday, the Mendenhall River had already surged to 10 feet, about twice as deep as it usually does.
“This will be a new record, based on all of the information that we have,” Nicole Ferrin, a weather service meteorologist, said at a Tuesday press conference.
Outburst floods occur when a lake filled with melting snow and ice overtakes the glacier holding it back, forcing the rapid release of water — “like pulling out the plug in a full bathtub,” according to the city of Juneau.
The first recorded outburst flood from the Mendenhall Glacier/Suicide Basin was in 2011, reports Climate.gov. It’s happened every year since, but has gotten significantly worse in recent years as a result of climate change.
Scientists say Alaska, as well as the rest of the Arctic, is warming twice as fast as the global average, prompting an acceleration in glacier melting and an increased risk of dangerous flooding.
Originally Published:
