BOSTON (AP) — Flooding this week in Massachusetts that put some dams at risk has raised concerns that the structures could be increasingly at risk as the region is hit by stronger, wetter storms.
There are thousands of dams throughout New England, and many were built decades if not centuries ago, often to power textile mills, store water or provide irrigation for farms. The worry is that they have outlived their usefulness and that climate change could unleash storms they were never built to withstand.
“When they were built, the climate was different. The design storms were different,” said Robert Kearns, climate resilience specialist at the Charles River Watershed Association.
Leominster, Massachusetts, Kearns noted, had nearly 11 inches of rain over several hours Monday night. At least two of the city’s 24 dams nearly collapsed this week, prompting the city to recommend evacuating residents before the threat subsides.
“These infrastructures, the culverts, the dams, were not built for the volume of water that we are seeing and will continue to see in the future,” he added.
A federal database lists nearly 4,000 dams in New England, with 176 classified as high-hazard facilities that are in poor or unsatisfactory condition. If these dams failed, they would pose a risk to people living downstream, as well as streets, neighborhoods and key infrastructure such as water treatment plants.
An Associated Press investigation in 2022 found that the number of high-hazard dams was on the rise: more than 2,200 nationwide, up substantially from a similar AP review conducted three years earlier. The number is likely even higher, though it’s unclear why some states don’t track the data and many federal agencies refuse to release details about dam conditions.
In the 2019 AP investigation, a review of inspection reports found a number of problems with the dams, including leaks that indicate internal failures, unrepaired erosion, holes from burrowing animals and extensive tree growth, which can destabilize earthen dams. In some cases, inspectors reported that spillways were too small to handle the amount of water that could result from increasingly intense storms.
Part of the challenge is that dam safety has long been ignored by policymakers, requiring many states to operate their dam safety programs on shoestring budgets, and repairs can take years. Supporters also say many programs lack transparency, so communities may not even know that a dangerous dam upstream poses a risk, while others complain that dam safety officials have been slow to recognize the threat of climate change.
“We’re not seeing a change in mindset related to dams that we should be seeing in light of the massive changes we’re seeing due to climate change in terms of particularly extreme storms,” said Emily Norton, executive director of the Charles River Watershed Association. “We believe there should be a much greater sense of urgency around the assessment and removal of dams.”
Christine Hatch, a hydrogeologist at the University of Massachusetts Amherst, said Massachusetts needs to do a statewide dam assessment to determine how best to spend its limited resources.
“The reality of climate change is that whatever we thought was safe enough when we built it is no longer safe,” Hatch said. “There’s not enough money to make them all bigger or upgrade them.”
An assessment is needed to decide which dams are essential and which are dangerous, Hatch said.
New England has seen numerous dam failures over the years.
More than 50 dams have failed in New Hampshire over the past century, including the Meadow Pond Dam, which failed in 1996, killing a woman and flooding a neighborhood. There have been about 70 in Vermont, including the 1947 East Pittsford Dam failure that devastated Rutland.
Five failed in Rhode Island during a 2010 storm, prompting the state to examine all of the dam’s spillways. A 2019 study found that a quarter of the state’s high-hazard dams couldn’t withstand a 100-year storm — an event with a 1% chance of occurring in any given year — and 17% couldn’t survive to a 500 year storm. , which has a 0.2% chance of occurring in one year.
Several dams nearly collapsed in Vermont this summer due to heavy flooding, including one that reportedly inundated parts of Montpelier, the capital.
Massachusetts Gov. Maura Healey said Wednesday that the administration is keeping an eye on dams across the state.
“We have already monitored the conditions of dams in many communities. Our Office of Dam Safety was on site, particularly in Leominster, the other day to act quickly by working with others to make sure those dams were shored up. But it’s something we’ll continue to keep an eye on,” Healey said.
Healey warned of the growing impact of climate change. A series of recent storms, including torrential rains in July that flooded farms in western Massachusetts, have highlighted the importance of strengthening the state’s defenses, she said.
“Obviously, this speaks to the need for federal funding that I’m pursuing and also the need for continued investment in resiliency and infrastructure because we’ve seen the devastating results of these storms,” he said. “What we’ve seen with these storms, and it’s different, is that they can change on a dime. The program cannot be the same.
The Barrett Park Pond Dam, located on a 3.6-hectare pond in Leominster, suffered significant damage during this week’s flooding. The failure of the dam, which dates back to the 1800s, could have sent water into a residential neighborhood downhill, state officials said.
Last inspected in 2021, the dam was found to be in poor condition. The city received a $163,500 grant for repairs, but it was still in the planning stages when the flooding occurred.
“The good news is that the 24 dams have held up,” Leominster Emergency Management Director Arthur Elbthal said, adding that the proposed repairs must go through the timely budget process.
“I know what we have here is what we can build on,” he said. “We certainly need to pay attention to them. … Every piece of infrastructure, whether it’s a road, a sewer line, a dam, we always try to keep it repaired and functioning as it should. I don’t see any change in that now.”
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Associated Press writer Steve LeBlanc in Boston contributed to this report.