Juneau's flood barriers are finished before Suicide Basin lets go

The U.S. Army Corps of Engineers says Phase 2 of the temporary flood defenses along the Mendenhall River is complete ahead of this year's expected glacial outburst flood.

The emergency work, built by Sealaska under contract with the Corps, put roughly 14,000 linear feet of HESCO barriers, more than 90,000 tons of rock armoring and earthen berms along about four miles of river — an immediate defense meant to be standing before peak August flood risk while longer-term fixes are studied.

Officials are telling residents not to mistake the wall for safety. "We saw it perform relatively well last year and we're very confident for this year, but the entire system is fragile," Juneau emergency programs manager Ryan O'Shaughnessy said this month, urging everyone in the evacuation area to heed advisories. "These are resilient structures. We do have a little bit of testing with them, but they are essentially sandbags, right?"

The valley knows the stakes. A 2023 outburst flood undercut homes along the river, the 2024 flood damaged hundreds more, and this summer nearly 1,900 homes sit under an evacuation advisory as officials prepare for another release, Alaska News previously reported.

A Senate water-resources bill would push the Corps toward a permanent fix, Alaska News previously reported — but for this summer, the guidance is unchanged: know your evacuation zone, follow city updates at juneau.org, and treat the barriers as risk reduction, not a guarantee.