United States: Alaska’s capital city, Juneau, is on high alert as record-breaking floodwaters threaten neighborhoods, fueled by heavy rain and melting snow pouring out from a glacier-dammed basin.
Officials issued urgent warnings late Tuesday, telling residents in the flood zone: “Don’t wait — evacuate tonight.” Many people have already left their homes to avoid being caught in the rising waters.
The source of the threat is the Mendenhall Glacier, located about 12 miles from downtown Juneau. It’s one of the city’s top tourist spots, famous for its easy walking trails and dramatic views. But just upstream, a smaller glacier has retreated in recent years, leaving behind a large basin known as Suicide Basin. Each spring and summer, it fills with rainwater and snowmelt. When enough pressure builds, the water bursts past the ice dam formed by the Mendenhall Glacier, spilling into Mendenhall Lake and then rushing down the Mendenhall River toward homes and businesses, according to CBS News.
The National Weather Service (NWS) said water began escaping the basin Tuesday morning, with flooding expected to peak between 8 am and noon local time on Wednesday. Meteorologists say this year’s outburst will likely set a new record, surpassing last year’s devastating flood, when the river hit 15.99 feet. This time, levels could reach 16.75 feet or more.
Flooding from Suicide Basin has become an almost yearly event since 2011. In recent years, it has destroyed houses, swallowed riverbanks, and damaged hundreds of homes. Last year alone, nearly 300 properties were affected. Some dramatic footage from 2023 showed trees collapsing into the raging river, followed by an entire house being swept away.
Scientists estimate a large outburst flood can unleash around 15 billion gallons of water — about the volume of 23,000 Olympic-size swimming pools. During last year’s flood, the river’s flow rate was about half the volume of Niagara Falls.
In preparation, Juneau city officials, working with state, federal, and tribal agencies, installed a temporary levee made of 10,000 large “Hesco” barriers — giant sand-filled blocks — along 2.5 miles of the riverbank. These are designed to protect more than 460 properties from flooding up to 18 feet, as per CBS News.
The US Army Corps of Engineers has begun studying the situation, exploring permanent solutions such as a full-scale levee. But the process could take years, which has frustrated residents who say they can’t wait that long for real protection.
Experts warn that these outburst floods will keep happening for decades — possibly another 25 to 60 years — as long as the Mendenhall Glacier remains in place to block the basin’s water.
