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.

USGS streamgages show flood conditions are now underway, with live cameras providing real-time views on the USGS HIVIS website. Glacier-caused flooding has become an annual threat since 2011, with record-breaking floods over the past two years that impacted more than 300 homes and threatened public safety.