The flooding from Suicide Basin into the Mendenhall Lake and River wasn’t the record-breaking surge of water that scientists thought was possible, but still reached 10.9 feet when it peaked at about 4:30 p.m. Thursday.
The waters quickly abated after the peak, though, and almost everything was back to normal Friday morning. U.S. Forest Service Ranger Michael Cantwell said Friday that everything went very smoothly during the response to the flood and afterward.
According to the National Weather Service’s Advanced Hydrologic Prediction Service, waters were dropping at about 3.5 inches per hour after cresting at 10.92 feet. By midnight it was under nine feet and by 8 a.m. Friday it was under seven feet. As of 5:15 p.m. Friday, it was down to 5.92 feet.
The Mendenhall Campground, which had been evacuated and closed the previous day, was back open as of 9 a.m., Cantwell said. As of 11 a.m., people were back in the campground, setting up their spots and enjoying the sunshine.
“It drained super fast,” Cantwell said. “It doesn’t usually drain that fast.”
The Forest Service had taken precautions in the area, knowing the waters would cover the roads in the campground and surrounding area as the flood reached eight feet.
Cantwell said people still made their way into the campground as the waters rose, and he had to kick several people out who walked in there and were wading through the water.
“When this water’s rushing through here, even when it’s six inches deep, you could not stand here because of the force of the current,” Cantwell said. “It will take you right down into those crags and the timber that’s in there. You’ll get stuck and you could drown. It could take your dog in there.”
These glacial floods, known as jökulhlaup, have been occurring on a semi-annual basis for the past few years, and local authorities have gotten comfortable responding to them. When looking toward future floods, City and Borough of Juneau Emergency Response Manager Tom Mattice had a few tips in mind.
In an email sent out this past week, Mattice outlined a few main ways Mendenhall Valley residents can prepare in the case of future floods. First of all, he suggested having a “go bag” at the ready for any major emergency. This bag, preferably a backpack or something easy to transport, ideally holds necessary survival tools, food, medications and any other items a person or family needs in the case of a disaster.
In the event of flooding, Mattice said in the email, people should stay away from the riverbank, flooded areas and bridges that go over the Mendenhall River. Cantwell concurred with that advice, saying that even locals who spend a lot of their time near the glacier can fall victim to fast-moving water.
People can keep up with floods or major disaster events via the CCFR Facebook page or the local NWS site, www.weather.gov/ajk.
• Contact reporter Alex McCarthy at 523-2271 or amccarthy@juneauempire.com. Follow him on Twitter at @akmccarthy.
