Jul 21, 2011
First glacier dam outburst flood on the Mendenhall Lake/River system that produced significant flood took place on July 21 2011. The source of the flood waters was from Suicide Basin and side basin on the Mendenhall Glacier, about a mile up from the glacier terminus. The Mendenhall Glacier was holding back water in Suicide Basin like a dam. The source of the flood waters was unknown for most of the event along with how much water was being impounded.
Source: NOAA National Weather Service Storm Events Database (event 479306). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Juneau Borough County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.