City updates Assembly on Glacier Lake outburst planning; Army Corps assists HESCO barrier maintenance, phase 2 assessment planned

The city manager briefed the Committee of the Whole on continuing work to respond to glacier-lake outburst flood risk. Manager Kester said the city has submitted a scope of work to the U.S. Army Corps of Engineers for technical assistance to maintain HESCO barriers and provide engineering oversight for near-term measures.

Kester told the assembly staff will pursue site assessments and prioritize segments of Phase 2 bank armoring so the city can estimate protected acreage and costs; Phase 2 will be materially more expensive than Phase 1 because of armoring needs. She said contract work to maintain HESCO barriers has begun and that staff are pursuing possible funding and Army Corps assistance to reduce local costs.

Assembly members asked about the accuracy of flood modeling, overtopping, valves and drainage through barriers, and the Corps’ timeline. City staff and Corps representatives said the rate at which the glacier-dammed lake releases water is a critical variable that past models did not fully capture; real-world observations in 2024 and 2025 diverged from prior model output. The Corps was described as moving quickly and exploring an expedited, midterm engineering solution that could materially reduce risk but would require sustained federal funding, and possibly CBJ match, to proceed on an accelerated schedule.

Kester warned that an expedited Corps timeline could compress public engagement and planning steps; staff will continue to press for both speed and public input. The assembly was told staff will return with more detailed cost and protection-priority information at the Oct. 30 meeting.