Sealaska Completes Juneau Flood Protection Work
Mendenhall River flood protection work by Sealaska installed 14,110 feet of barriers and placed 112,872 tons of rock near Juneau.
Sealaska completed flood protection work along Alaska’s Mendenhall River on July 3, 12 days ahead of its July 15 contract deadline and before August glacial outburst flood risks increase. Working under contract with the U.S. Army Corps of Engineers, the company installed 14,110 linear feet of HESCO barriers, placed 112,872 tons of rock armoring and reinforced about four miles of river corridor. A 60-person workforce built a 1,100-foot flood protection levee, reinforced riverbanks and cleared hazardous debris. The work targets flood threats linked to potential releases from Suicide Basin into the Mendenhall River.
River Corridor Reinforced
At peak production, crews moved and placed more than 1,630 tons of material a day. The team constructed an approximately 12-foot-high levee in approximately three to four weeks using locally sourced fill from the Montana Creek pit, crushed rock roadway surfacing and rock armoring on both the river-facing and land-facing slopes.
Critical flood-control work was added after the original scope was complete without extending the original contract schedule. Crews also constructed access roads and coordinated with property owners to move equipment and materials through the corridor.
David McQueen, general manager of Sealaska’s construction division, said:
“Completing this project before the peak flood season required extraordinary effort from our crews and partners. We mobilized quickly, worked in challenging conditions and delivered critical protections for communities in our home region.”
Response To Recent Flooding
The project follows two consecutive years of record flooding in the Juneau area. Glacial outburst flooding damaged nearly 300 homes in 2024. In 2023, floodwater destroyed structures along the Mendenhall River and prompted city officials to issue an emergency declaration.
The HESCO barriers are intended to provide an immediate layer of protection while the U.S. Army Corps of Engineers evaluates long-term solutions for recurring glacial outburst flooding in the Juneau area. Rock armoring and other measures are designed to reduce riverbank erosion and further land loss along vulnerable river sections.
Local Workforce Participation
About 25% of the skilled workforce comprised Alaska Native employees. Sealaska said the project created opportunities for local and Indigenous workers while delivering critical infrastructure improvements.
Heath Barger, Sealaska senior project manager, said:
“As a shareholder, former intern and past scholarship recipient, I understand how important these opportunities are. We’re proud that Alaska Native workers helped lead work that directly protects Southeast Alaska communities.”
Protection Before August
Flood risks increase in August, when melting ice, rainwater and snowmelt can trigger a release from Suicide Basin and send water down the Mendenhall River. During construction, crews used equipment inspections, spill prevention measures and on-site spill response resources when working near water.
With the barriers, levee, debris removal and riverbank protection complete, the project has put immediate flood-control measures in place before flood risks increase in August.
