Juneau Residents Flee As Suicide Basin’s Glacial Waters Threaten Catastrophic Flooding

Juneau residents scrambled to evacuate their homes Tuesday as rising waters from the Suicide Basin glacial outburst threatened unprecedented flooding along the Mendenhall River.

The National Weather Service forecasts the Mendenhall River will crest between 16.25 and 16.75 feet on Wednesday, exceeding this year’s previous record of 15.99 feet. Officials have classified this as a “Major Flood Stage” event, requiring urgent action from the community of 30,000.

Nearly 900 homes in flood zones received informational flyers as authorities intensified evacuation warnings. A special hotline was activated to provide residents with vital updates as the situation develops.

Emergency officials reached hundreds of homes with critical evacuation information as floodwaters threatened Juneau neighborhoods.

“This is going to be a record event based on our available data,” said a National Weather Service representative. The flooding results from both the glacial dam release and recent moderate to heavy rainfall in the area.

The Backloop Bridge closed at 8:30 p.m. Tuesday to guarantee public safety as water levels continued to rise. Emergency managers stressed that rising waters and floating debris could hamper rescue operations, making early evacuation essential.

Homes along the Mendenhall River face the highest threat, with hundreds of properties in the potential inundation area. Temporary barriers were installed earlier this season in attempts to minimize property damage. Officials deployed approximately 10,000 Hesco barriers to protect over 460 properties in vulnerable areas.

The Suicide Basin glacial lake outburst floods have been an annual concern for Juneau since 2011. In previous years, these floods have destroyed houses and affected hundreds of homes throughout the Mendenhall Valley neighborhoods.

USGS and NOAA maintain monitoring equipment including laser sensors and cameras that provide real-time data and four daily images to track the flood’s progress. This information is shared via local media, websites, and social media.

The ice dam began releasing water Tuesday morning. Peak flooding is expected between 8 a.m. and noon Wednesday, with water levels beginning to drop on Thursday.

Three days of heavy rainfall before the dam release have worsened conditions, leaving residents bracing for what could be the worst flooding in years. An emergency evacuation shelter has been established at Floyd Dryden Middle School for displaced residents.