Update 9 a.m.: The National Weather Service reported in an 8:30 a.m. update that the Mendenhall River height was at 15.92 feet and falling. The river crested at 7:15 a.m. at 16.65 feet. A flood warning is in effect through 8 a.m. Thursday.
Update 10 p.m.: According to a 10 p.m. update from the National Weather Service, Mendenhall River is expected to crest at a height of 16.25 feet to 16.75 feet between 8 a.m. and noon Wednesday. The update to the crest timing is due to rain masking the start of the sub glacial release and refining the initial start time of the event.
As of 10 p.m., Mendenhall River height was at 12.95 feet and rising. Suicide Basin height was 1,270 feet and falling.
Original story: The National Weather Service in Juneau issued a flood warning Tuesday morning for a glacial-dammed lake outburst following indications that Suicide Basin began releasing.
The crest is expected around Wednesday afternoon, with record-breaking levels expected to be between 16.3 and 16.8 feet for the Mendenhall River, according to the Tuesday morning alert.
In an emergency alert, the City and Borough of Juneau advised evacuation for those in the flood zone. An emergency shelter is scheduled to be open at Floyd Dryden Gym, beginning Tuesday afternoon. Those within the 17-foot inundation level are urged to evacuate.
Nicole Ferrin with the National Weather Service said during a Tuesday morning briefing that the flood warning was issued after “a lot of analysis,” with the added complication of rainfall causing significant rising of the lake and river before the anticipated basin release. She confirmed that a sub-glacial release had occurred, with Mendenhall Lake at 9.5 feet and rising as of 10 a.m. Tuesday morning.
“This will be a new record,” Ferrin said. “Based on all of the information we have.”
Ferrin said estimating the exact timing of the basin release is difficult because of the recent rainfall. She said the River Forecast Center in Anchorage suggested that the release began around 4 p.m. on Monday. The river was expected to reach above 12 feet overnight Tuesday and reach above the major flood stage of 14 feet on Wednesday morning. The flood is anticipated to crest around 16.6 feet Wednesday afternoon, with Ferrin saying a fair estimate of the crest is anywhere between 16.3 and 16.8 feet.
Sam Russell with Capital City Fire and Rescue said Tuesday morning that they were still seeing people climbing on the preventative HESCO barriers in an attempt to observe the rising waters. Additionally, there have been reports of individuals trying to observe the waters on Back Loop Road and Brotherhood Bridge. Russell urged Juneauites to avoid those areas and reminded citizens that as flood levels increase, rescue efforts become more complicated. He pointed out that there are multiple online livestream cameras active along the river for those curious about the flooding.
Russell said those with homes in the flood inundation zone may be stopped by first responders and volunteers while traveling through the area. They may ask for contact information and personal details like names and addresses to confirm the return and safety of those traveling within the flooded areas.
Sabrina Grubitz, Incident Commander with Tlingit & Haida, said on Tuesday that the main objective of the United Command remains protecting the life and safety of citizens and first responders, and protecting infrastructure. She said sheltering would be available at Floyd Dryden for those who need to evacuate.
According to Ryan O’Shaughnessy, CBJ emergency programs manager with the City and Borough of Juneau, door hangers were distributed Monday afternoon to 892 residences along the river, and an additional 200 residents have been directly contacted and urged to evacuate because they are in the potentially soon-to-be-inundated area.
The HESCO barriers installed this year are expected to protect against up to an 18-foot flood stage. The flood in 2024 crested at 15.99 feet.
Superintendent Frank Hauser from the Juneau School District said they planned to monitor the flood situation closely and would make a determination about school closures for Thursday by noon on Wednesday. Notifications about potential closures will be sent out via automated calls, emails, texts, and the JSD app. If a closure is necessary, Hauser said the district plans to close all schools. He encouraged families and staff to ensure their PowerSchool contact information is up to date.
The JIC is partnering with the Red Cross to create an emergency evacuation shelter at Floyd Dryden Gymnasium at 3800 Mendenhall Loop Road. While they are not able to accommodate pets at the Floyd Dryden Shelter, Juneau Animal Rescue offers emergency sheltering for pets through their Safe-Keeping Program.
Residents in the flood inundation area who are not sheltering at Floyd Dryden are invited to move vehicles to St. Brendan’s Episcopal Church (4207 Mendenhall Loop Road), Shepherd of the Valley Lutheran Church (8198 Keegan Street), Christ Lutheran Church (10300 Glacier Highway), and the Juneau Christian Center (8001 Glacier Highway).
Capital Transit will assist with the transportation of evacuees from Riverview Senior Living and Trillium Landing to Red Cross Shelters as well as overflow shuttling from Floyd Dryden to contingency shelter locations if the primary shelter capacity is exceeded, according to CBJ’s online guide to flood preparedness.
For more information and details on the flooding, including maps and live streams of the river, visit juneauflood.com. You can sign up to receive emergency alerts on the release by texting “CBJ” to 38276.
This is a developing story.
