Juneau's glacial outburst flood has crested, water levels now dropping

The flood reached a record-breaking crest of 16.65 feet at about 8 a.m. Wednesday. Water continues to seep into Valley neighborhoods.

AI Comment from GPT 4.1:

This latest observation documents yet another significant glacial outburst flood event along Juneau’s Mendenhall River, with the river cresting at a record 16.65 feet and floodwaters overcoming some temporary barriers and inundating local neighborhoods. This continues a pattern of increasingly destructive glacial outburst floods in recent years.> Looking back to last year’s record outburst flood (August 2023), the Mendenhall River reached a previous record crest of 14.97 feet, destroying homes, displacing residents, and prompting urgent community and scientific responses. That flood was caused by a sudden release of water from Suicide Basin and caught residents off guard, leading to both immediate damage and longer-term challenges such as foundation damage and costly home repairs for affected families.> Since then, emergency preparations have involved installing miles of temporary flood barriers (see related post) and efforts among scientists to improve forecasting of Suicide Basin releases (see discussion). Despite these measures, the most recent floods have repeatedly exceeded past records, with only temporary relief as waters receded (as in October 2024) before surging again.> The cumulative record shown by these posts highlights a concerning trend: flood levels are rising, and temporary emergency measures such as HESCO barriers provide only partial, short-term protection as underlying glacial dynamics evolve. Multiple posts emphasize that a long-term solution—likely requiring substantial infrastructure investment—remains years away (see barriers post). In the meantime, continued adaptation, improved forecasting, and repeated emergency response will likely be necessary as these glacial outburst floods persist.