Officials ordered an evacuation advisory for about 5,000 residents in Juneau’s Mendenhall Valley as a glacial outburst flood from Suicide Basin began. The flood was expected to peak Thursday morning, with authorities warning that barrier failure could lead to major flooding.

Juneau and its state, federal, and tribal partners are preparing for another annual glacial outburst flood from Suicide Basin, with flooding expected in early August. Officials have strengthened flood barriers, expanded evacuation planning, and are urging Mendenhall Valley residents to prepare now.

Juneau is rebuilding temporary flood barriers along the Mendenhall River to prepare for another glacial outburst flood from Suicide Basin, but rising construction costs led the city to scale back the wall’s planned height. The U.S. Army Corps of Engineers estimates the annual floods could persist for about 25 more years while longer-term solutions are evaluated.

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

A longer-term fix could still be years away and cost hundreds of millions of dollars.