Moderate Flooding Anticipated in Juneau, Alaska Due to Glacial Dam Outburst

A flood warning was issued following a glacial lake outburst in Juneau, Alaska. Suicide Basin, part of the Mendenhall Glacier, has been causing floods annually since 2011. These floods affect Mendenhall Lake and River. "We expect moderate flooding from this event, not major flooding," stated Nicole Serrin, a meteorologist with the National Weather Service in Juneau. Residents were given 24 to 36 hours to prepare.

The flood warning remains effective until Monday. The river is expected to peak at approximately 3.35 to 3.5 metres early that day, according to the weather service. Authorities advised people to avoid the river due to slippery banks caused by recent snow. The basin accumulates rainwater and snowmelt during spring and summer, eventually forcing its way out beneath the glacier.

Flood History and Impact

In August, around 100 homes and some businesses suffered damage when floodwaters reached neighbourhoods. The Mendenhall River reached a record crest of 4.9 metres then, surpassing last year's flood level by about a foot. This resulted in water extending further into the Mendenhall Valley.

Suicide Basin began refilling with autumn rain over recent months, according to Serrin. It remains uncertain how quickly it will drain or if it will empty entirely. Juneau, home to about 30,000 residents in southeast Alaska, is accessible only by plane or boat.

Officials continue to monitor the situation closely as they assess potential impacts on the community and surrounding areas.