Juneau, Alaska, is facing another year of destructive glacial floods as the Mendenhall Glacier continues to melt at an alarming rate. The city’s residents are bracing themselves for the worst as the icy meltwater from Suicide Basin flows towards the Alaskan city.
Every summer, the glacier acts as a dam for the jumble of icebergs and meltwater in the basin. As it fills with ice melt and rainfall, the pressure builds until the water reaches a tipping point, forcing its way out underneath the glacier and down towards the city below. The past two August floods have been particularly destructive, and this year’s torrent poses a persistent summertime threat to those living along the Mendenhall River.
To mitigate the damage, Juneau officials worked with the U.S. Army Corps of Engineers to build massive Hesco barriers along the river in flood-prone areas. These barriers, made from cloth bags filled with dirt or sand and reinforced with a metal frame, are designed to prevent destruction and act like giant sandbags. The source of the floodwater is Suicide Basin, which abuts the Mendenhall Glacier.
The glacier’s melting has led to an increase in glacial outbursts, with over 30 occurrences since 2011. The need for a solution has grown more urgent as the floods have become more destructive. Residents and officials have debated various options, including building a dam around Mendenhall Lake or tapping into Suicide Basin.
For this year’s flood, authorities are relying on the Hesco wall as a temporary solution, paid for by Juneau taxpayers. The Army Corps recommended the approach and provided the barriers. Authorities warn residents to stay away from the barriers and bridges along the riverbank where people have gathered to watch the flood.
As the glacial flooding began this week, the Mendenhall River was already in a minor flood stage due to heavy rains over the weekend. The level of Mendenhall Lake reached 16.5 feet, surpassing the record set last year when it reached 16 feet. Authorities are closely monitoring the situation and urging caution as they wait to see how effective the barriers will be in preventing destruction.
Source: https://www.washingtonpost.com/climate-environment/2025/08/12/alaska-glacier-juneau-flooding-barriers