Since the devastating storm on Aug. 8, 2023, Needham has suffered four other significant wet-weather events with more than 200 residents reporting significant property damage. The combination of a high water table due to an historically wet year and the increased frequency of intense storms has caused repeated flooding, leaving residents wondering who’s responsible. Do homeowners bear the risk and repairs? Should the town be doing more to prevent the devastation? In short, the answer to each is yes.
A working group was created in the aftermath of the August storm to assess damage and evaluate what long- and short-term changes both homeowners and the town need to make. Composed of members from the Select Board, the town manager’s office, the public works, engineering and building departments and the water and sewer division, the group has held 21 rounds of site visits with several homes each round. More are being scheduled.
“The intention is to provide short-term solutions and provide transparency,” said Carys Lustig, director of DPW and member of the task force. She said many people are unaware of the work already being done in stormwater management. “We listen to what they experienced that day, what flooded, how the water moved. It gives us a better idea of those areas for the stormwater master plan.”
The master plan considers not only stormwater capacity from a building code perspective, but also the capacity of the town to mitigate it, said Select Board member Kevin Keane, who is part of the working group.
“Some of the houses that have been built expose the owners to significant chance of flooding,” said Keane. “We know we have to tighten that up. That’s what the Stormwater Bylaw Working Group is working on.” Any changes to the current building codes and bylaws will not be retroactive, they will affect only new projects. Keane said the group will look at the current bylaws to see where they can improve with regard to flooding risk.
“The building inspector needs code to enforce,” he said. “If it’s not written down, you can’t make it up.”
The master plan spans 10 years and includes expanding the size of the underground stormwater pipes working backward from the Charles River. The plan will also include conversations with the Conservation Commission about the brooks and culverts, which are part of their jurisdiction. “These short- and long-term solutions, they affect conservation,” said Lustig. “Hopefully we can work together to mitigate some of these issues.”
Residents will need to be patient, though, Lustig said, because the process of replacing parts of the more than 100 miles of pipes at $1,000 per linear foot has to be done in small pieces so as not to completely disrupt traffic. “It’s not like in the Midwest, where a drainage system is designed and then a town is built,” she said. “Even if we got all the funding we needed, you can’t tear up half the town and impact traffic. So we still have to have a phasing plan.”
In the meantime, she said the town will allocate money from the $280,000 in ARPA funds it received to get a consultant’s recommendations on how to creatively and effectively store water temporarily during severe wet-weather events. “The town drains pretty well, but it’s a matter of buying an hour or half-hour,” she said. Roadways, brooks and culverts are all used to handle heavy rainfall and prevent flooding. Raised sidewalks, which help keep the water from overflowing, may be one measure to help in the short term. The study will also look at places where retention tanks could be placed to hold water temporarily during a storm, but the density of the town may make finding ideal locations challenging.
Another group has been in the works through DPW, whose timeline was recently accelerated as a result of the storms. It is tasked with looking at stormwater capacity. “Previously the town was only mandated by the EPA and the federal government to monitor [water] quality, not quantity,” said Keane. “But now it’s an issue. We moved it up in the budget.”
Keane said the sluicescape repair at the Rosemary dam came in under budget, so some of the funds were reallocated to start engineering a study on capacity. Town Meeting will be asked this spring to vote on additional funds. The study will look at the hydrology and kinks in the system, or how water moves across town, Keane explained. Based on the findings, the town will create a mitigation plan.
“Mind you — no system could be built to stand a storm that probably we’ll get because of climate change,” he said. “Everyone is also going to have to learn how to harden their properties to protect them from flooding.”
Keane said flooding has been so localized that different measures will help in different situations. Oak Street residents had groundwater issues with water coming up through basements, other neighborhoods had water coursing through their yards. One resident lives at the foot of a long slope with a yard that is graded directly toward the basement door, and in Jarvis Circle, underground garages and sloped driveways created issues. In some cases, residents had water from wetlands in their yards. As the working group visits each site, the building and engineering departments have been instrumental in advising homeowners how to avoid — or at least minimize — flooding in the future.
“I think the biggest obstacle is having the frank conversation of what a basement is intended to function as and how we have developed basements everywhere,” said Lustig. “Basements are historically a protection system for our homes, not a living space.” She said residents should consider investing in fortifying and protecting their electrical system and HVAC over aesthetics. “[People need to be] realistic about how much investment they’re putting in them.”
Some short-term measures homeowners can take to help prevent flooding are installing a rain garden and bioswales to draw water away from the home, put in window wells and move sump pumps to better locations in their basements. Another measure residents can take is helping to keep catch basins clear. With north of 4,000 catch basins around town, it is impossible for the DPW to keep on top of every single one during a storm.
“All the drains matter when you have a critical storm,” said Keane. “In the December one, the high winds kicked up the oak leaves and pinecones and clogged up stuff. Residents going out to brush the drains off was key.”
Keane also offered a note of caution for those using sump pumps or french drains. “Do not drain it into the sink, tub or toilet — never put it into the sewer system.” He said the two systems are not interchangeable, and it is important to understand the difference between the two. “A stormwater drain is a stormwater drain. A sewer system is a sealed system that goes out to Deer Island.”
Excess stormwater can overwhelm the sewer system, causing it to overflow into the flood water and spread sewage everywhere. If that were to happen, everything the water touched would have to be disposed of. Additionally, said Keane, the town pays for the capacity of sewage that flows through the system, so using it for storm water greatly increases the cost for all residents.
Similarly, Lustig reassured residents that because the two systems are separate, they should not be worried about causing flooding by flushing a toilet or taking a shower.
Lustig said they know these types of storms are not going to go away, and the town’s focus going forward is protecting infrastructure and updating the systems to handle these more frequent events. She said a dashboard is being developed for the website to enable residents to see how the pipes and other systems work together and to keep them updated on progress.