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ALERT: Suicide Basin releasing, peak flooding up to 16.6 feet expected at about 7 a.m. Thursday
- Mark Sabbatini
- 7 hours ago
- 3 min read
Officials urge people to evacuate at-risk areas; water levels expected to reach major flood stage about 1 a.m. Thursday, flood warning in effect until 4:30 a.m. Friday
By Mark Sabbatini
Juneau Independent
This is a developing story.
An alert of a glacial outburst flood from Suicide Basin was issued just before 5 p.m. Tuesday, with peak flooding of the Mendenhall River between 16.1 and 16.6 feet expected at about 7 a.m. Thursday, according to National Weather Service Juneau.
The river is expected to reach the major flood stage at 14 feet at about 1 a.m. Thursday, Andrew Park, a NWS Juneau meteorologist, said during a livestreamed update shortly after 10 p.m. Tuesday.
"Once the river goes above that it really takes a different feel," he said. "It really becomes a dangerous river once we hit major flood stage. So I would encourage everyone to remain away from that river, evacuate if you can. The river is a very scary place to be above major flood stage."
People in at-risk areas are being urged to evacuate the area on Wednesday before the river reaches the flood stage. An emergency evacuation shelter at the Floyd Dryden campus at 3800 Mendenhall Loop Road is opening at 8:30 p.m. due to the flood alert, which is in effect until 4:30 a.m. Friday.
Back Loop Road is set to be closed when the flood level reaches 12 feet, which currently is forecast to happen at about 5 p.m. Wednesday. Pedestrian access to the Brotherhood Bridge will also be closed, although vehicle traffic over the bridge will be allowed. The Mendenhall Valley Public Library closed early at 6 p.m. Tuesday, and city facilities, fields and trails along the Mendenhall River will be closed Wednesday and Thursday.
HESCO barriers and other protective measures have been taken for most of the flood zone areas, but officials are emphasizing that residents plan on evacuating the area because damage that causes a breach to the barriers could pose a life-threatening flash flood or other risks.
"It's deceptive how swift water can carry you away," said Ken Murphy, a safety officer for the Alaska Department of Transportation and Public Facilities, during a 3 p.m. Tuesday safety briefing by emergency response officials. "You can't swim in it. Water always wins when you fight against it. Never gamble your life against a flood. Do not risk your safety because water always wins."
"Standing on the bridge or on a HESCO barrier to get a better look is a deadly gamble," he added.
People can observe live views of the Mendenhall River and flood zone areas via a multitude of online cameras at Juneau Flood Solution Advocates’ "Eyes On The River" YouTube channel as well as KTOO’s online live webstream.
Aaron Jacobs, the senior service hydrologist at NWS Juneau, said during the Tuesday afternoon briefing the peak level and flow are expected to be a bit below record levels set last year, when the river crested at 16.65 feet. He said peak tides of more than 18 feet are already factored into the flood forecast scenarios.
The river level typically drops quickly after it reaches its crest, and the evacuation advisory will likely be lifted within 12 to 18 hours afterward, said Ryan O’Shaughnessy, Juneau’s emergency programs manager.
The Mendenhall River was at 4.5 feet as of about 10 p.m. Tuesday, far below last year’s level of about nine feet due to an atmospheric river occurring before the flood began.
A warning that Suicide Basin was overtopping was issued at 8:39 a.m. Tuesday, with officials stating a release from the basin was likely within one to six days based on past floods. But Jacobs noted during the briefing “things can really change rapidly over the next 24 hours" and that officials were monitoring a drop in the basin as a possible release.
A 24-hour flood hotline for non-emergency questions to officials is at 907-500-0890. Information and updates are also available at the city’s flood preparedness website. City sites closed Wednesday and Thursday include Mendenhall Valley Public Library, Dimond Park Field House, Dimond Park Aquatic Center, all nearby fields (Dimond Park, Melvin Park, Mendenhall River Community School), and nearby trails (Kaxdigoowu Heen Dei, Juneau International Airport’s Emergency Vehicle Access Road or Airport Dike Trail), according to the city’s website.
• Contact Mark Sabbatini at editor@juneauindependent.com or (907) 957-2306.
