Glacial Outburst Threatens Record Flooding in Juneau, Alaska

Juneau, Alaska — A glacial outburst from Suicide Basin is threatening severe flooding in Juneau, with rising waters expected to disrupt the state capital this week.

Officials reported that the basin has released water, leading to potential flooding along Mendenhall Lake and River. “Residents in the inundation zone should evacuate immediately until floodwaters recede,” city officials advised.

Glacial outbursts occur when melting snow, ice, and rain pool in a glacier-fed lake, eventually overflowing the glacier’s barrier. This incident involves the Mendenhall Glacier and Suicide Basin, located approximately 10 miles from downtown Juneau.

The National Weather Service (NWS) issued a flood warning early Tuesday, predicting that the Mendenhall River will rise several feet by Wednesday. As of early Wednesday morning, the river reached a major flood stage, topping 14 feet and is expected to crest at about 16.6 feet later in the day, potentially breaking the record set last August.

As waters rose, large debris including trees was pulled into the river, exacerbating the danger. “It’s very dangerous right now. Stay away if you can,” cautioned Andrew Park, a meteorologist with the NWS, advising boaters to be alert for floating dangers.

Significant flooding was reported Tuesday night, with areas around Mendenhall Lake experiencing over three feet of water buildup, according to the NWS. A glacial outburst last year saw similar flooding effects, impacting over 100 homes and causing residents to encounter unprecedented flooding conditions.

City officials have installed flood barriers in areas hit hard by last year’s outburst, although no mandatory evacuations are currently in place. Residents are urged to act before waters peak. “If you are told to evacuate, stop what you are doing and immediately seek shelter,” stated Republican Sen. Lisa Murkowski.

In response to the emerging situation, Alaska Governor Mike Dunleavy issued a preemptive emergency declaration Sunday to expedite state resources for local response measures. “Our goal is to act early to reduce impacts and preserve community safety,” he emphasized.

Juneau has a population of around 33,000 residents and is bordered by coastal waters. The frequency of glacial lake outbursts has reportedly increased since 2011 and has become more severe in recent years, a pattern attributed to climate change.