JOINT BASE ELMENDORF-RICHARDSON, Alaska — Governor Mike Dunleavy has issued a State Disaster Declaration in response to an imminent threat of catastrophic flooding caused by a glacial lake outburst flood (GLOF) originating from Suicide Basin, a side basin of the Mendenhall Glacier.

The declaration follows formal requests for assistance submitted by the City and Borough of Juneau (CBJ) and the Central Council of the Tlingit and Haida Indian Tribes of Alaska. Glacial lake outburst floods have become a recurring issue in the region, triggering state and federal disaster recovery responses in both 2023 and 2024. In 2025, the State of Alaska issued a preemptive disaster declaration when an outburst became imminent. Thanks to a temporary flood barrier constructed by CBJ and the U.S. Army Corps of Engineers (USACE), record-high water levels during the 2025 event were contained, preventing severe inundation in residential neighborhoods.

This latest declaration activates the State of Alaska Public Assistance disaster recovery program.

Additionally, the declaration allows the state to temporarily waive certain administrative regulations that could otherwise impede immediate prevention or mitigation efforts, such as clearing waterway debris that threatens flood-control barriers.

Hydrologic monitoring conducted by the National Weather Service (NWS) confirms that water has begun releasing from Suicide Basin, causing water levels on the Mendenhall River to rise.

“CBJ, the Tlingit and Haida Tribe, USACE, and local partner agencies have done a remarkable job constructing flood defenses, coordinating response efforts, and preparing Mendenhall Valley residents,” said Bryan Fisher, Director of the Division of Homeland Security and Emergency Management. “Their proactive efforts serve as a model for community safety and emergency preparedness.”

The State Emergency Operations Center (SEOC) has elevated its operational state to actively support local and tribal management efforts. This includes facilitating interagency coordination, streamlining emergency permits, managing public communications, and positioning response assets. The SEOC will deploy three emergency management personnel to Juneau to monitor conditions on the ground during the flood window.

Residents in affected areas are urged to stay informed and prepare for potential flooding. Official updates, evacuation guidance, and emergency resources can be accessed at Juneau Glacial Flood Dashboard.