Glacier Outburst in Alaska Threatens Record Flooding in Juneau for Third Straight Year

A dangerous wave of water from a glacial lake outburst is threatening to cause potentially record-breaking flooding in Juneau, Alaska, for the third consecutive August.

City officials confirmed Tuesday that a sudden release of water from Suicide Basin, adjacent to the Mendenhall Glacier, is pushing water levels in Mendenhall Lake and River to dangerous heights. The National Weather Service has issued a flood warning, predicting the Mendenhall River will crest at around 16.6 feet on Wednesday afternoon — surpassing last year’s record of 15.99 feet.

Last August’s flood was described as “unprecedented,” damaging more than 100 homes and topping 2023’s early August flood level by a full foot. Roughly 1,000 residents and businesses are in the flood-prone area, which now has a protective barrier installed after the 2024 event. While there are no mandatory evacuations, officials are strongly urging residents in the 17-foot inundation zone to leave before water peaks.

“This is likely to become a life-threatening situation,” said U.S. Sen. Lisa Murkowski in a statement on X, advising residents to seek safe shelter immediately if told to evacuate. Alaska Gov. Mike Dunleavy has issued a preemptive disaster declaration to streamline emergency response efforts.

Glacial lake outbursts occur when a basin filled with meltwater overtops the ice holding it back, releasing a surge similar to “pulling out the plug in a bathtub.” Scientists link the recurring events at Suicide Basin to climate change, which is causing the Mendenhall Glacier to thin and retreat, leaving more space for meltwater to accumulate each summer.

The current flood is expected to reach major flood stage early Wednesday afternoon and remain there until around midnight before receding Thursday.

Credit: CNN Newsource

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