JOINT BASE ELMENDORF-RICHARDSON -- The U.S. Army Corps of Engineers – Alaska District is preparing a technical report to evaluate alternatives intended to mitigate the risks of glacial lake outburst flooding (GLOF) in the Mendenhall Valley near Juneau.
USACE is inviting the public to submit their comments to the agency to help define the scope of analysis or array of alternatives to be considered during the development of this report. Currently, there are five conceptual flood-control alternatives to be evaluated: flood-control dam(s); levees or floodwalls; bypass channels; Suicide Basin lake tap; and infrastructure relocation.
“Your feedback will guide our team in evaluating and developing these conceptual alternatives, including their environmental impacts,” said Col. Jeffrey Palazzini, district commander. “This is an important opportunity for the public to engage directly in the federal process and influence the technical report.”
This notice also fulfills requirements of Executive Order 11988 “Floodplain Management” to provide the public the opportunity for early review of plans or proposals with actions in floodplains.
The purpose of the technical report is to recommend an enduring solution to reduce the risk of flood damages associated with future Mendenhall GLOF events. Record flows and water levels were observed in the Mendenhall River during the August 2025 event. A new record GLOF event has occurred each year since the first event in 2011. Under USACE’s Public Law 84-99, Advance Measure authority, temporary flood barriers have been installed and contributed to decreased inundation of structures and infrastructure. However, the urgent need for an expedited and enduring solution remains.
Comments and inquiries should be emailed within 30 days of this notice directly to the district’s Public Affairs Office at public.affairs3@usace.army.mil.
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Release no. 25-007