With water levels high, stay alert for glacial outburst floods

As Juneau experiences heavy rain and high water levels, residents along the Mendenhall River are advised to exercise extra caution and stay alert for potential jökulhlaups (glacial outburst floods).

Glacier ice is unpredictable, and an outburst could occur at any time. Under current conditions, a jökulhlaup would likely lead to significant flooding along the Mendenhall River. In 2023, jökulhlaup flooding damaged or destroyed multiple residences along the river.

In the event of a jökulhlaup, CBJ will work with CCFR and JPD to alert residents in the area and issue evacuation warnings if necessary.

Residents west of Riverside Drive are strongly encouraged to establish an evacuation plan and prepare a go-bag of basic emergency supplies as a precautionary measure.

To check conditions at Suicide Basin, visit the National Weather Service’s monitoring page at weather.gov/ajk/SuicideBasin. To see maps modeling floodwater inundation levels, visit water.noaa.gov/gauges/MNDA2.

For more information about how jökulhlaups occur, where to monitor glacier conditions, and what to do in case of an emergency, visit CBJ’s jökulhlaup FAQ.