Representatives from the U.S. Army Corps of Engineers (USACE) – Alaska District and the City and Borough of Juneau (CBJ) will be available for a public information sharing session about the Mendenhall Valley glacial outburst technical study and how it supports a long-term mitigation solution. The event is scheduled for Wednesday, July 30 from 6:00 – 8:00 p.m. Alaska Standard Time in Juneau at Thunder Mountain Middle School for anyone interested in learning about this effort.
The purpose of this event is to provide a general project status update on the ongoing work related to the technical study and the path forward. USACE will provide a brief presentation on the technical study followed by a question-and-answer session. USACE representatives will be from its Civil Works Branch focused on the long-term solution to mitigate the flood risk in the Mendenhall Valley. The USACE Emergency Management Program team will not be present, however, representatives from CBJ, Tlingit & Haida, the National Weather Service, the American Red Cross and the University of Alaska, Southeast will also be available with technical information and flood preparedness resources following the USACE presentation.
USACE is conducting a technical study for flood risk management of the Mendenhall Valley in Juneau under Section 8315 of the Water Resources Development Act of 2022. The cost of the study is about $4.75 million and fully funded by the federal government. The primary goal of the technical effort is to establish the existing conditions within the study area so the USACE team can assess the viability of potential long-term solutions. Elements that will be included in the final report are evaluations of hydrology and hydraulics as well as geomatic, geotechnical and economic conditions within the study area. A high-level environmental assessment will be performed as well.
The Mendenhall Valley is a densely populated residential area within the CBJ and located about 11 miles north of the Capitol Building in downtown Juneau. Currently, the area is at a significant and ongoing risk of flooding due to glacial lake outburst flood (GLOF) events from the Mendenhall Glacier. These GLOF events occur when a glacial dammed lake drains rapidly, releasing a surge of water downstream. These outburst floods pose a major threat to people and infrastructure in the region.