Suicide Basin update: 1,340 feet on Monday, just 28 feet below its fill capacity; water rose 22.2 feet last week

Official forecast is still for ice dam to be full by mid-August, with current average fill rate of three feet per day

The fill level in Suicide Basin as of about 10 a.m. Monday, Aug. 4, 2025. (Official Suicide Basin monitoring website)

By Mark Sabbatini

Editor

Exactly one year ago, Suicide Basin broke and about 40 hours later Juneau’s worst glacial lake outburst flood ever damaged nearly 300 homes. This year officials say the ice dam is still about a week or so away from being full, and barriers intended to protect homes are in place when the jökulhlaup occurs.

Suicide Basin’s water level is about 1,340 feet as of Monday, just 28 feet below its fill capacity of 1,368 feet, according to the National Weather Service Juneau’s official monitoring website. The basin rose 22.2 feet during the past seven days and, at an average fill rate of three feet per day, the basin is expected to reach capacity by mid-August.

A year ago on this date the basin was at 1,368 feet and two years ago at 1,387 feet.

"Based on UAS drone surveys this summer compared to last year, the spillway elevation has lowered by 3 feet from ice melt," the most recent observation notes. "The inflow rate into the basin can change through the summer due to periods of above normal temperatures along the ice field and rain events."

The extended weather forecast through Sunday is mixed with a chance of rain through Tuesday, a clearing period until Thursday night and rain forecast through the weekend. Temperatures are mostly forecast to be seasonal with highs in the 60s and lows in the 50s.

Information about preparation, alerts and other details is available at the Juneau Glacial Flood Dashboard website.

• Contact Mark Sabbatini at editor@juneauindependent.com or (907) 957-2306.