A second glacial outburst flood in Juneau has crested and the Mendenhall Lake level is starting to come down, according to the National Weather Service in Juneau.
Water level in the lake peaked at 10.18 feet at 5:45 a.m. It’s now dropping rapidly.
Data from a laser gauge and cameras in Suicide Basin show that the basin has started to drain, says the weather service.
As of 6:30 a.m., the lake was at 9.88 feet and going down. Still, a flood warning remains in effect until 7:45 a.m. on Saturday.
According to data from the U.S. Geological Survey, it’s not uncommon for Suicide Basin — the glacier-dammed lake responsible for the flood — to release more than once in a year.
Since 2023, secondary releases that took place in September or October were significantly smaller than initial floods in August.
The flood this August peaked at 14.7 feet.
The record-breaking flood in August 2025 crested at more than 16-and-a-half feet. And the secondary flood that followed in September 2025 crested at 9.6 feet.
