Suicide Basin, an ice-dammed lake on an arm of Mendenhall Glacier, has filled up with meltwater and sent destructive surges of water into Juneau for 3 straight summers.

Residents in some parts of Juneau prepared to evacuate ahead of what could be a record surge of flooding as rainwater and snowmelt in a huge basin dammed by Alaska’s Mendenhall Glacier started to flow downstream toward the capital city.

Emergency officials say new barriers appear to have worked as planned, with only scattered reports of water leaks.