Installing a semi-permanent levee along four miles of the Mendenhall River using what are known as Hesco barriers to help protect against flooding from Suicide Basin is being recommended by the U.S. Army Corps of Engineers, according to a report scheduled to be presented to the Juneau Assembly at a special meeting at noon Thursday.
The levee and other mitigation measures are being considered by city leaders at the same time dozens of residents affected by record flooding this year have formed a group to consider their own possible action, which has scheduled a public meeting at 5:30 p.m. Thursday at Riverside Baptist Church.
Both city leaders and citizens’ group are facing the possibility of another major flood this month, while also pondering remedies for anticipated flooding next year and the years beyond. The groups also say there is a desire and need to work cooperatively, but worry their counterpart might limit or hamper preventative efforts.
“There are some residents who 100% trust that the city is going to have a sound action plan and our neighborhoods will be saved from any potential flood in October,” said Kathleen Rado, a member of the Juneau Flood Fighting, Mitigation and Support Group. “And then there are neighbors, there are residents who do not believe that, that see the issue as so large that we can’t fathom how movement can happen that fast.”
However, a concern expressed during a special Assembly meeting last week is residents acting on their own could take actions — such as water diversion — that could have adverse impacts elsewhere.
“I know that people in the neighborhoods are forming groups trying to figure out if they need to do things themselves, which then becomes, I think, quite dangerous because then it’s all the sort of the consequences of all the individual actions that might affect the river,” Deputy Mayor Michelle Bonnet Hale said.
The Assembly has to date approved $3 million to fund half of a Corps of Engineers study on long-term remedies that could include proposals such as a drainage tunnel through a mountain, $1.375 million to repair and protect public infrastructure, and $400,000 for mitigation planning and updated flood mapping.
The water level in Suicide Basin was at about 1,222 feet as of 2 p.m. Wednesday, roughly the same level as the end of June and beginning of July, according to the National Weather Service Juneau’s monitoring website. A full release of water from the ice dam would result in the Mendenhall River reaching a peak of 10.5 feet. While that officially would surpass the moderate flood stage, it would be far below the 15.99 feet on Aug. 6 that swamped hundreds of homes (with the most severe and unanticipated damage coming after the river surpassed the 15-foot level that was the previous record last year).
City leaders are scheduled to be at both of Thursday’s meetings, with the midday Assembly meeting conducted via Zoom reviewing the proposed levee and other information compiled during the past week while members of the Corps of Engineers Flood Fighting Team visited Juneau. The information is also expected to be shared during the citizen’s group meeting as those residents evaluate their options.
Quick decision on using barriers to build levy poses risks either way
The primary recommendation of the Corps of Engineers flood experts during their weeklong visit is installing Hesco barriers along the developed side of the Mendenhall River, Koester wrote in a memo being presented to Assembly members at Thursday’s meeting. The sand-filled barriers have a three-foot-square footprint and are four feet tall, and can be stacked as a pyramid to create higher barriers if necessary.
As proposed the levee would ultimately be four miles long, with the initial priority being from Marion Drive to Killewich Drive to Meander Way since “this is where the river jumped the bank.”
“Depending on the event, we could redirect the flow to the unpopulated side of the river,” she wrote. However, “installation on Marion will present challenges as many of those homes do not have sufficient frontage.”
The Corps of Engineers will provide the barriers and ship them to Juneau for free, and train city officials on installing them, Koester wrote. She stated the barriers can arrive three weeks after being requested — but the city must use them immediately.
“If we are not actively working to install barriers, we run the risk of them being redeployed to another area of the country that needs them,” she wrote. “They also would like us to place one order instead of requesting in phases.”
The city is also asking the Corps of Engineers to “provide technical assistance to homeowners who want advice on how to protect their property,” according to Koester. She said the Corps can provide 60,000 sandbags, with the city managing distribution.
“If each of the 289 homes that flooded requested bags, that would be 200 per household, which would go a long way towards protecting low points, doors, etc.,” she wrote. “It is common practice in areas prone to flooding for local municipalities to distribute sandbags for homeowners to install.”
However, there are several concerns about using such barriers, Koester notes. Among them is many of the barriers would be on private property and thus pose potential problems such as commercial loaders tearing up yards while the barriers are placed, homes lacking enough stable riverfront to place the barriers and what to do if some people resist having the barriers on their property.
“Under the Governor’s disaster declaration, we can legally enter private property to prevent a disaster — however, to the extent we can coordinate with willing homeowners, the better,” Koester wrote.
Koester suggests four courses of action the Assembly can take:
• Do nothing: “This is the simplest option. The cost is minimal and CBJ avoids liability. However, we do not know how much worse the flooding could be in the future. We could easily lose a significant portion of our housing stock and population over the next few events.”
• Provide sandbags to residents in affected areas.
• Install Hesco barriers where the river jumped the bank.
• Install the four-mile Hesco levee.
“If CBJ is going to do anything beyond providing sandbags to individual homeowners, I am of the opinion we must protect as much of the bank as possible,” she wrote. “While a shorter project (Marion Drive to Killewich Drive to Meander Way) could be enough this year, the volume of water in the basin is unpredictable and likely growing. I propose a holistic approach that allows CBJ staff to get started with the priority spots while we study and formulate a plan for the entire project.”
A community group seeking solutions
Rado said members of the neighborhood group aren’t entirely sure what the short- and long-term solutions to safeguarding their property and themselves are, “but we know that we’re going to accomplish a lot more together than we are going to separately.”
“It’s a wide range of that we believe that we’re going to be able to help each other through this as a community and also we recognize that we’re fighting Mother Nature, and unless something can be done to stop the flooding in our neighborhoods we’re going to continue just supporting each other through these disasters,” she said.
A Facebook page for the group has more than 300 members and more than 60 people attended a planning meeting last week, Rado said. One of the efforts now underway is to determine what needs and means of assistance people have. One member has purchased a large number of sandbags he is using to protect his home and distributing to neighbors, for instance, while others are making plans for how to quickly remove belongings from homes if a flood is imminent.
While many people in the affected neighborhoods are aware of efforts city officials are making to address the situation, there is concern that not enough was done after last year’s flood to protect homes and officials were caught unaware by the severity of this year’s flood, she said.
“We were all in our homes when it flooded, and so our community isn’t ready for this and we need to get ready,” she said. “And the only way that we’re going to be able to do it is by putting pressure on our government to make us get ready for it, as well as being able to get the word out there and being able to spread the word from people who have lived through the flood.”
• Contact Mark Sabbatini at mark.sabbatini@juneauempire.com or (907) 957-2306.
