During the second week of August, the Mendenhall Glacier in Juneau, Alaska, initiated a glacial lake outburst flood, releasing almost all water held in Suicide Basin. In the weeks prior to the resulting flood event, the U.S. Army Corps of Engineers deployed resources and personnel to help the community prepare for the impending flood. Coordination with local and federal partners strengthened the response effort, which successfully improved the project following the flood in 2025.
Over the course of the 2026 event, USACE temporary barrier walls and pumps provided critical short-term protection along the Mendenhall River and effectively safeguarded large areas of the community during the peak of the floodwaters, which crested at 14.7 feet on Aug. 13.
“Our accomplishments in the Mendenhall Valley are a direct result of close collaboration across all levels of the organization and numerous stakeholders in the region,” said Brig. Gen. Joseph “Clete” Goetz, former commanding general of the Pacific Ocean Division. “I am incredibly proud of our work at the 2026 flood and deeply grateful to the community for their ongoing support and collaboration as we aim to address this critical issue.”
During the 2026 construction season, USACE installed 2.72 miles of barriers along the river to protect against flows up to 63,500 cubic feet per second. In addition, the construction team built a 1,100-foot-long earthen berm north of Back Loop Road and armored 1.85 miles of riverbank to assist with erosion control. Furthermore, 41 pumps, 500 supersacks and 112,500 sandbags rounded out this year’s USACE effort, each contributing to the success of the overall flood mitigation mission.
“This project required a significant number of resources from USACE to execute on time in anticipation of the 2026 event,” said Daryl Downing, emergency management specialist in the Seattle District and project manager for the phase two effort. “Although this year’s flood was at a lower level than expected, the barriers still served a valuable purpose and worked as intended.”
While not all pumps were used during the flood, those that saw action performed as expected by expelling water that seeped behind the gabion baskets. Provided by USACE via the National Flood Fight Materiel Center in Illinois, the pumps were monitored via aerial drone and activated when water arose in areas of concern. Among the pumps actively deployed along the Mendenhall River during the GLOF, around 15 experienced active operation.
“We were very happy with how the pumps functioned during the flood event,” Downing said. “Drone monitoring enabled us to respond quickly to locations of need, and the system worked very well as another layer of protection and risk reduction behind the barriers.”
In anticipation of the glacial release, USACE deployed 28 employees from around the enterprise to Juneau for direct support during the flood event. Experts including hydraulic engineers, geotechnical engineers, emergency management specialists and others from eight separate districts and divisions provided in-person expertise before, during and after the flood, ensuring smooth operations and streamlined communication.
“Our team was a critical element of our success in this response,” said Col. Victor Trujillo II, commander of the Alaska District. “I would like to thank all of our volunteers from across the organization who gave their time and expertise to be here with us for the 2026 flood.”
USACE leadership continues to be fully engaged at the Mendenhall project to coordinate ongoing flood response activities with stakeholders and community members. Mr. Lee Forsgren, principal deputy Assistant Secretary of the Army for Civil Works, visited the Phase Two project on Aug. 7, 2026 and met with members of the media to discuss USACE efforts. Goetz and Trujillo were also present in the community for the flood, contributing leadership and representing the organization as the event occurred.
“USACE is fully committed to helping the Mendenhall Valley community achieve a solution to this unique problem,” Trujillo said. “We are a proud partner to the people of Juneau, and the team’s robust efforts this year demonstrate our dedication to effective flood fighting at all levels of the enterprise.”