Evacuation advisories distributed to homes, officials set flood preparation plans in motion as Suicide Basin spills over
- Mark Sabbatini
- 2 days ago
- 6 min read
Updated: 2 days ago
No break in ice dam as of early Monday evening; officials say elevated lake and river levels occurring due to spillover from basin
By Mark Sabbatini and Ellie Ruel
Juneau Independent
This is a developing story.
Emergency officials have activated a range of prepatory actions due to Suicide Basin reaching full capacity, although as of early Monday afternoon a break in the ice dam has not yet occurred, according to city and weather officials.
Those actions include workers distributing information fliers to homes in neighborhoods considered at risk of flooding and activating an emergency information hotline (907-500-0890). Some trails have been closed including the Nugget Falls Trail at the Mendenhall Glacier and the Kaxdigoowu Heen Dei (Mendenhall River Trail).
Businesses and private entities are also making preparations. Goldbelt Inc. and the Greater Juneau Chamber of Commerce, for instance, announced Monday their offices at Vintage Business Park will be closed for the remainder of the week.
As of 1 p.m., the City and Borough of Juneau’s community emergency response team began distributing flood information flyers to houses within the inundation zone, which has been defined as any property that is predicted to flood if the Mendenhall River reaches 17 feet and the HESCO barriers fail.
Residents who receive notices on their door are strongly encouraged to sign up for emergency alerts and make evacuation plans now so they are ready to vacate homes when a release from Suicide Basin occurs.
Lisa Hickman was part of the canvassing team and is also involved with the U.S. Coast Guard Auxiliary, which will provide aid during the flood if needed. She said residents should watch both the flood information dashboard and CBJ links provided on the flyers.
“Just be as informed as you can, be as prepared as you can,” Hickman said. “That's the best-case scenario, that everybody gets prepared. Part of the links will talk about what's a good go bag to have, and then as we get more information about where the safe zones are.”
Some residents thought the paper was an actual evacuation notice, but Hickman and coworker Michael Cut assured them another emergency alert would be sent to their phones when it was time to evacuate.
Ryan O'Shaughnessy, the city’s emergency programs manager, said notices being distributed are evacuation advisories, not mandates.
"We are issuing those evacuation advisories although we are extremely confident in the HESCO barriers' capability to protect the neighborhoods," he said. "We're not willing to bet on that with anybody's lives or safety."
The information hotline will provide details about flood preparations, emergency shelter and parking options, and other practical matters, O'Shaughnessy said. He said 911 should be used rather than the hotline for flood-related emergencies.
Suicide Basin reached its fill point late Sunday. In past years a glacial lake outburst flood has typically occurred within six days of the basin’s capacity being reached, according to the official Suicide Basin monitoring website. Last year’s release occurred just after 10 a.m. Sunday, Aug. 4, and the Mendenhall River reached its peak flood stage about 40 hours later during the early morning hours of Tuesday, Aug. 6.
Water is spilling over the top of Suicide Basin which, combined with heavy rain, has resulted in an elevation of the water level at Mendenhall Lake, said Aaron Jacobs, senior service hydrologist for the National Weather Service Juneau, during a press briefing Monday morning. But he said the rain is expected to taper off by Tuesday morning and no significant precipitation is forecast later this week, which should result in the lake level dropping if a break in Suicide Basin doesn’t occur.
"Currently we are seeing a little drop in the water levels in Suicide Basin," he said. "That's from the water that's overtopping the ice dam — (it) is slowly eroding that ice dam down a little bit each time. At this time there is no indication that there is an outburst flood event taking place."
An update posted at the monitoring website at 2 p.m. Monday states "at this time, there is no indication of a basin release from Suicide Basin. The basin is over topping and slowly eroding the overflow channel which is lowering water levels slowly." The height of the basin is 1,359 feet, compared to a peak height of 1,380 feet last year and just above 1,400 feet in 2023.
Jacobs said he’s aware of people posting photos of a waterfall at the base of Mendenhall Glacier and "what we're seeing there is just a general glacial flow in the runoff that we're seeing from the precipitation and just the regular melt from the Mendenhall Glacier."
This year’s extensive preparations follow two years of record floods that damaged more than 300 homes and a significant amount of public infrastructure. A major difference this year is a two-mile semipermanent levee of HESCO barriers that officials are hoping will prevent most or all damage that occurred in previous years, even if the river exceeds the 15.99-foot crest from last year by a couple of feet.
The Suicide Basin website as of early Monday afternoon shows a hypothetical maximum river level of 16.3 feet, but Jacobs has cautioned that is "a moving target" that will be affected by various factors including further drops in the basin’s water level before a release occurs.
A few residents were making last-minute preparations by stocking up on sandbags Monday afternoon at the Dimond Park Field House parking lot. A stack of empty bags and a large pile of sand were left over from previous distribution events, and were quickly put to use by people worried their existing personal flood barriers weren’t enough.
Melinda and Joseph Liddle live on Rivercourt Way, and had floodwaters in their garage and crawlspace during last summer’s glacial outburst flood event. They already had a two-sandbag high wall around their house, but decided to add extra after seeing a neighbor’s taller border.
“You look around the neighborhood where most houses have sandbags, it probably gives other people motivation,” Joseph Liddle said. “I hope those HESCO barriers are going to work.”
Melinda added that they “never know how high the water can go,” so it’s better for them to be safe than sorry.
O'Shaughnessy said public services such as electricity to neighborhoods will be monitored once the river begins posing a threat.
"They do not plan to immediately cut power for the neighborhood that is behind the HESCO barriers," he said. "If we do start to see inundation in that neighborhood, power will be cut immediately to the entire neighborhood and then turned back on in phases starting from the intersection of Mendenhall and Steven Richards, and sort of work its way back up through the neighborhood."
Water and sewer services should not be impacted, O'Shaughnessy said.
In addition to the Suicide Basin monitoring website, updates and other full information are available at the Juneau Glacial Flood Dashboard. Also live online as of Monday is an "Eyes on The River" website by Juneau Flood Solution Advocates showing live webstreams from various points in flood-prone areas and a YouTube livesteam with flood updates by KTOO.
• Contact Mark Sabbatini at editor@juneauindependent.com or (907) 957-2306. Contact Ellie Ruel at ellie.ruel@juneauindependent.com.
