For the third consecutive year, a wave of water gushed out of an Alaskan glacial lake, threatening the state’s capital city of Juneau. But, flood barriers installed by the city managed to prevent disaster from unfolding in the picturesque port town despite record-breaking water levels this week.

A huge basin of rainwater and snowmelt dammed by Alaska’s Mendenhall Glacier has started to release, and officials on Tuesday urged residents in some parts of Juneau to evacuate ahead of what could be a record surge of floodwater downstream.

One of Alaska's most populated cities is bracing for potentially catastrophic flooding as a basin dammed within the Mendenhall Glacier has started to release water.

The National Weather Service issued a special weather statement indicating that it could take up to six days for the basin to release floodwaters into Mendenhall Lake.

A powerful surge of glacial meltwater is once again testing Juneau's resilience, and this time, the ripple effects could reach well beyond city limits — impacting thousands of travelers headed to Alaska’s capital by cruise ship.

The all clear has been given and residents have been allowed to return to their homes in Alaska’s capital of Juneau after a glacial lake outburst sent debris-filled water rushing down the Mendenhall River on Tuesday night and Wednesday morning.

A melting glacier pushed the Mendenhall River to a record-high crest of more than 16 feet, prompting a major flood threat to the Alaskan state capital. But more than two miles of newly installed barriers protected neighborhoods from a repeat of the severe flooding of the past two years.