Glacial lake outburst creates flood concerns

The National Weather Service kept a flood warning in place until late Thursday for the Mendenhall River and Mendenhall Lake even though it said water levels had crested and begun to recede. Because the situation was so unusual for this area, the agency could not say Thursday afternoon that the worst was over.

Lakes can form under, on top of or around glaciers, with the water being dammed by glacier ice or debris. Flooding occurs when that water, somehow, is let loose. Randy Host, a hydrologist with the U.S. Geological Survey, said this happens yearly on the Taku, and there are regular instances of it happening on the Mendenhall, too, but as "little blips." Nothing like this.

At least two spur roads were closed, including one leading to the popular West Glacier trail. Mendenhall campground also was closed.

Tom Mattice, the city and borough's emergency manager, said several homes in the View Drive area had "seen water," with reports of water in one garage and water touching another's foundation. Residents were urged to leave earlier in the day, and he said electricity to the area had been shut off. He hoped service could be restored swiftly once the danger had passed.

About 10 homes are in that area but not all were threatened by the floodwaters, Mattice said. He didn't immediately know whether any homes suffered damage.

The situation developed rapidly. Val Horner said she called her friend, who lives in the area, Thursday morning, after hearing about the flood warning. Her friend had no idea, looked outside and saw water near her deck.

"In over 30 years here, I've never seen water like this," said Horner, whose nearby home wasn't in any danger.

People parked along the highway to take photos above the rushing river. The curious trudged through water on the flooded closed-off spur roads, some without shoes, to get a better look, while kids splashed in the water, finding relief from the summer sun in the icy water.

Eliza Lane, 25, dipped in her toes.

"We're from Juneau, so this is exciting news to us," she said. "Look how much water. That's crazy!"