Javascript notice

Whale! It looks like you have Javascript for this browser disabled. This page uses Javascript to display menus and interactive content. Some elements on this page may not function properly until Javascript is enabled.

How to enable Javascript for your browser

The University of Alaska is an Equal Opportunity/Equal Access Employer and Educational Institution. The University is committed to a policy of non-discrimination against individuals on the basis of any legally protected status.

UAS is committed to providing accessible websites: www.uas.alaska.edu/policies/accessibility.html

Glacial lake outburst flood in Juneau

Last modified: August 14, 2026 09:08:46

As forecasted, a glacial lake outburst flood took place in Juneau on Aug. 12 and 13, 2026. The University of Alaska Southeast Juneau campus, including campus housing, is not located in the flood evacuation advisory zone. There were no direct impacts to campus.

08/13/26 at 5 p.m.

The Glacial Lake Outburst Flood Unified Command announced that the flood threat from Suicide Basin has ended. The water has receded. Evacuated areas are open to residents.

-----

8/11/26 at 4:48 p.m.

The National Weather Service in Juneau announced that Suicide Basin in Mendenhall Glacier is draining at 4:48 p.m. on Tuesday, Aug. 11.

The floodwaters in Mendenhall Lake and the Mendenhall River have historically crested 24-48 hours after this main basin release begins. Flooding is expected late Wednesday thru early Thursday.

The UAS Juneau campus, including campus housing, is not located in the flood zone. We do not anticipate any direct impacts to campus. The Juneau campus is operating normally and open regular summer hours.

For those spending time off campus, please take steps to ensure your safety. If you are in the flood evacuation zone, evacuation is advised.

See the City and Borough of Juneau’s Guide to Flood Preparedness to view the evacuation advisory map and access public resources such as emergency shelter (including for pets), evacuation routes, vehicle parking, and the CBJ Flood Information Hotline.

Additional resources are available to Juneau-based University of Alaska students and employees, including temporary on-campus housing, parking and more. See section below: UAS flood response: Resources for students and employees.

-----

08/11/26 at 8:35 a.m.

The National Weather Service in Juneau announced that Suicide Basin is full at 8:35 a.m. on Tuesday, Aug. 11. Historically, a basin release has occurred 1-6 days after the basin reaches capacity.

The UAS Juneau campus, including campus housing, is not located in the flood evacuation zone. We do not anticipate any direct impacts to campus.

Areas around Mendenhall Lake and Mendenhall River in the nearby Mendenhall Valley may experience flooding. If you have not yet, now is the time to prepare:

See the CBJ Guide to Flood Preparedness to sign up for emergency alerts, view the evacuation advisory map, find out how to prepare, and access public flood response resources.

Additional resources are available to Juneau-based University of Alaska students and employees. Find more information below.

The University of Alaska Southeast is prepared to support Juneau-based University of Alaska students and employees who may be impacted. Resources, including temporary housing, parking, drying equipment, counseling and more, are available:

University of Alaska students: Contact Dean of Students Damian Medina to connect with services and resources, ask questions, or relay concerns.

University of Alaska employees: Visit the UAS Employee Hub for the latest information and to reserve access to flood response services and resources. If you are unable to access the Employee Hub or have any questions or concerns, please contact the UAS Incident Management Team at uas.incidentmanagement@alaska.edu or your supervisor.

CBJ Guide to Flood Preparedness: Sign up for emergency alerts, view the evacuation advisory map, find out how to prepare, and access public flood response resources including a flood information hotline. From the City and Borough of Juneau.

Juneau Glacial Flood Dashboard: Find flood maps, forecasting, FAQs and historical data. Maintained by UAS in collaboration with the Alaska Climate Adaptation Center.

Since 2011, a side basin of the Mendenhall Glacier, known as Suicide Basin or Kʼóox Ḵaadí Basin, has periodically filled with water and then rapidly drained out beneath the glacier. The flood inundates areas around Mendenhall Lake and the Mendenhall River, and has increased over time. In 2025, HESCO barriers were placed around the river, which reduced impacts to surrounding neighborhoods.

See the StoryMap Glacier Outburst Floods: Mendenhall Glacier for a visual explanation of this phenomenon. UAS scientists are at the forefront of researching and sharing findings about glacial lake outburst floods in Alaska.

Flooding timeline: What to expect

Basin is full: When the National Weather Service determines that the basin is full, the City and Borough of Juneau and partners will issue an evacuation preparation advisory via SMS text. A full basin means that the main release event will likely begin in 1 to 6 days.

Basin is releasing: When the basin release begins, the National Weather Service will issue a flood warning. An evacuation advisory and notices will be pushed out through multiple channels. The floodwaters in Mendenhall Lake and the Mendenhall River typically crest 24-48 hours after the main basin release begins.

Water has receded: When it is safe to return to the evacuation zone, the City and Borough of Juneau and partners will issue notice via SMS text.

Seasonal timing: Juneau’s glacial outburst floods have occurred between June and October, with major events usually taking place in July or August. It is not uncommon to have multiple floods in a year, with a major summer event followed by one or more smaller floods in the fall.