Hopkinton, R.I. - Kathy Palmer remembers the loud rumbling, then the wall of water sweeping over the small farm where she and her family have lived for the last 50 years.

"It was like a tidal wave," she said. "We heard this weird sound, and my father screamed. I called 911. I said, this isn't from the flood."

The torrent rushed through her property and that of her neighbors and onto Canonchet Road, closing it for two days, then spread over portions of Routes 3 and 95. It came at about 5 p.m. on March 30, 2010, as record downpours were drenching the entire region of southeastern Connecticut and Washington County, R.I.

This sudden surge, though, didn't come directly from the sky, but from the 179 million gallons of water pouring out of nearby Blue Pond when the old earthen dam that pooled the waters of Canonchet Brook collapsed. When years of neglect - the dam owners had been notified twice by the state in 2007 that the dam needed repairs - met the deluge of 2010, the pressure from the rising waters proved too much for the weakened structure to withstand.

"No work was ever undertaken to fix the problems, and during the flood, nobody was watching this dam," said David Chopy, chief of the Office of Compliance and Inspection at the Rhode Island Department of Environmental Management. "It was just luck that nobody got hurt or killed when the dam ruptured and the water started pouring over the embankment."

Dam owner Ashville Corp. and its parent company, Greene Plastics, a bead manufacturer also on Canon-chet Road, were fined about $55,000 by the state for not maintaining the dam. The company has appealed the fine. A message left with Greene Plastics officials requesting comment was not returned.

Chopy said four other dams in the state also collapsed during the 2010 floods, but none of the owners had been previously notified about needed repairs, so no fines were levied. At least three of the others were, like the Blue Pond dam, privately owned.

"What all five had in common was that they were all poorly maintained, and none of them were being monitored by anyone" during the flood, he said. Though no one can say for sure, it's possible that placement of sandbags and other emergency measures during the flood could have prevented collapse, he said.

In southeastern Connecticut, several state- and privately owned dams were damaged by the floods and needed repairs, but only one collapsed, said Art Christian, supervising civil engineer of the dam safety section of the state Department of Environmental Protection. That dam was on Phillips Pond in the Pachaug State Forest, far enough from any homes for the draining waters to cause damage. Christian said it will be rebuilt.

About $250,000 worth of repairs will be done on the dams at Glasgo, Beachdale and Beach ponds, all on the Pachaug River in Griswold and Voluntown, once the Federal Emergency Management Agency provides about 80 percent of the funds to cover the work, he added.

"We would have preferred to do it right away, but we had to wait to get the cost-sharing money from

FEMA," he said. "We're hoping to get the work done this summer."

One dam inspector in R.I.

Harold Ward, professor emeritus of environmental studies at Brown University in Providence, has the views of both an expert and an affected homeowner of what can happen when a dam is neglected. Ward lives in Hope Valley, R.I., and the waters from Blue Pond reached his property, which had never flooded like this before, he said. He was forced out of his home for two weeks after 6 feet of water filled his home. A geothermal furnace, three freezers, an oil tank and a tool collection were lost or badly damaged, he said.

The lesson of the 2010 floods, he said, is simple.

"People should fix their dams when they're leaking, or take them down," he said. Particularly as climate change is increasing extreme rainfall events, dam inspections and maintenance need to become a higher priority, he said.

"There's one dam inspector for the whole state," he said.

Statewide, there are 671 dams, according to Gail Mastrati, spokeswoman for the Rhode Island DEM. Connecticut has 4,300 dams and two inspectors, Chrisian of the Connecticut DEP said.

After the waters receded, Ward calculated how much of the flooding had come from Blue Pond. Based on measurements from stream gauges upstream and downstream of the pond, he estimated the collapse added 3 feet to the peak water heights during the flood.

His assessment of the inaction by the Blue Pond dam owner: "unconscionable."

Michael Kennedy, a Waterford resident who has owned property on Canonchet Road for two decades, is also disgusted by the situation. The force of the water after the dam broke, he said, ripped up a 15-ton bridge that was the only access to his land, where he had someday hoped to build a house. There is a also a pond on his property. The surge carried a huge chunk of land and deposited it in the pond, along with a large tree that wedged itself in the dam at one end. Granite blocks in the dam structure were thrown loose. Repairs thus far haven't been possible because of access problems.

Kennedy, a former Millstone worker "immersed in the safety culture" who now works as a consultant, said he's long been a conscientious dam owner, making sure his dam was kept in good repair and even serving on a Rhode Island task force on dam safety in 2001.

"It bothers me that Greene Plastics was so negligent," he said. "There's a lot of anger."

He contacted Greene Plastics, he said, and was told to contact its insurance company, which denied his claim. Now he and some of his neighbors are talking with a lawyer about a class-action suit, citing a Rhode Island law that puts liability for impacts from dam failures on the dam owners. Among those planning to be part of the suit is Kathy Palmer.

"I lost a small barn, a swing set and a covered bridge to the back of my property, and my septic system was under water and a lot of our soil washed away," she said. Other neighbors, she added, lost cars. The only assistance she was able to get, she added, was a $10,000 loan for repairs.

"That dam had been in disrepair for a lot of years and we all knew it," she said.

Her neighbor, Ivar Babb, said Greene Plastics told him after the flood that he and his neighbors shouldn't expect any compensation. Babb, director of the Northeast Undersea Research Technology & Education Center at the University of Connecticut at Avery Point in Groton, recorded a video of the damage to his neighborhood in the immediate aftermath, so there's at least a historical record of what the dam break caused.

"They (Greene Plastics) said it wasn't their problem, it was a freak event they weren't responsible for," said Babb, who lost a greenhouse on his property. He said he considered suing, but a lawyer told him the expense would probably exceed any settlement.

Beyond the property damage, the scouring and erosion from the dam surge has changed the natural landscape of the area, Palmer and Kennedy said, altering the wetlands and woods in its path. Blue Pond itself has drained completely, and Greene Plastics has not informed DEM that it has any plan to rebuild the dam.

"It'll just naturally revegetate back into the kind of wetland it was before the dam was built," Chopy said.

Christopher Fox, executive director of the Wood-Pawcatuck Watershed Association, said the story of the Blue Pond dam should serve as a warning.

"If there was a hero of the storm, it was that more of these decrepit dams that haven't seen maintenance in 50 years didn't collapse," he said. "This is a wake-up call telling us, 'Repair your dams or prepare to have them removed, one way or another.'"

j.benson@theday.com