Date: Fri, 11 Jul 2014 19:02:36 EDT
Summary: A glacial outburst flood from the Suicide Basin in the Mendenhall Valley is producing flooding along the Mendenhall River in Juneau, Alaska.
Suicide Basin is a tributary to the Mendenhall Glacier that was recently filled with ice. Glacial retreat has opened an area adjacent to the Mendenhall Glacier that fills annually with rain and snowmelt. The first outburst from this basin was in 2011 and resulted in minor flooding. The outburst in 2012 was much smaller and there was no outburst in 2013. This year the basin filled beyond the 2011 level and the outburst flood began on July 9, 2014.
Discharge at the Mendenhall River near Auke Bay streamgage (15052500) is greater than the previous peak of record of 16,400 cfs and the predicted peak for this event is approximately 20,000 cfs. Access has been restricted to residential areas near the river and there is concern for flood damage to a temporary construction bridge in the river.
USGS personnel are working with the Alaska State Department of Transportation to measure discharge and survey bed elevations at a scour critical bridge on the Mendenhall River. A team of three hydrologists will be making measurements this evening and tomorrow morning.
Alaska WaterWatch table for the Mendenhall River
Alaska WaterWatch map for the Mendenhall River