Officials in Juneau, Alaska, have declared a state of emergency as a result of a glacier lake outburst flood that is causing extensive damage near the city, including the destruction of structures. The flooding is attributed to a rupture in Suicide Basin, a side basin connected to the Mendenhall Glacier, located approximately 12 miles north of Juneau. Such floods occur when a dam containing a glacial lake gives way.
The National Weather Service reports that several structures along the Mendenhall River have been destroyed due to the flooding, including the loss of two homes and partial damage to another. Additionally, a condo building has been significantly compromised and is at risk. The flooding event is described as “extreme” by the NWS, with debris and trees littering the river.
Surprisingly, the flooding has impacted areas that were not previously prone to such events. The Mendenhall Lake level reached a record high of 14.97 feet, surpassing the previous high of 11.99 feet in July 2016. Erosion along the riverbanks has also been significant.
Videos captured by residents show the extent of the flooding, including the collapse of multi-story structures into the river. Roads and bridges have been closed due to the flooding, and residents have been urged to stay away from the river for safety reasons.
The Suicide Basin has been releasing glacier lake outburst floods since 2011, causing inundation along Mendenhall Lake and the Mendenhall River. Climate change is believed to increase the risk of flooding from melted glaciers, according to a study published in Nature Climate Change in 2021. The situation in Juneau underscores the potentially devastating consequences of glacial melt and its impact on local communities and infrastructure.