Mendenhall River Flooding 2025. Over two days in early august, a glacial lake on a tributary of the mendenhall glacier burst through its ice dam and drained into the mendenhall river. Flooding of the mendenhall river crested at 4:15 a.m.
Juneau’s glacial outburst floods have happened every year since 2011, but this year was the worst by far. Over two days in early august, a glacial lake on a tributary of the mendenhall glacier burst through its ice dam and drained into the mendenhall river.