Older drainage systems weren’t made to handle so much water at once, resulting in street and basement flooding.
When Tropical Storm Henri hit last August, Gerard Street in Manchester was underwater in a matter of minutes. The storm dumped five inches of rain on the town.
"Everyone's thinking we're losing power. We're going to lose power. No one was thinking flooding," said Erin Hayden.
Firefighters used Hayden's canoe to rescue her neighbor Iris Castellano from her flooded home.
"It's just overwhelmed so much. I lost so much," she said.
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Kiya Young's grandfather also had to be rescued by canoe. Young, who was at work when the storm hit, remembers wading through the high water to get to her house.
"It was above my knees," she said.
The neighbors said it was unlike anything they've ever experienced.
Manchester Town Manager Steve Stephanou said the unprecedented flooding was the result of severe runoff from nearby Bigelow Brook.
Just a couple of miles away on Ambassador Drive, the road collapsed when the culvert underneath was overwhelmed by rushing water.
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The area was hit again by the remnants of Hurricane Ida days later.
"What used to be the 100-year storm is now a 50-year storm. So these high intensity events are happening twice as often," said Michael Dietz, director of the CT NEMO Program at the University of Connecticut.
The NEMO Program helps guide municipalities on best practices for storm water management. Dietz said these more frequent and intense storms are the result of our changing climate.
Figures from the National Oceanic and Atmospheric Administration (NOAA) show the average rainfall for a 100-year storm in Connecticut has increased from seven inches in a 24-hour period to 7.8 inches.
“When you get seven inches of rain in a 24-hour period, now think about the landscape, how everything is saturated now. So that extra inch of rain on that saturated landscape really makes what can be catastrophic conditions,” Dietz said.
West Hartford resident Tom Restelli said his property has flooded three times since 2019.
“It's really hard to keep the water out and we don't know what to do," he said.
Like the folks in Manchester, Restelli has spent tens of thousands of dollars trying to mitigate the problem.
Unlike Manchester, Restelli's home is in a flood zone. He lives on Trout Brook Drive near one of four culverts determined to be undersized and in need of replacement, according to a 2018 study commissioned by the town.
"It's not up to the task anymore," Restelli said. "I don't know if the storms are bigger, the system's older, but that's what's happening."
West Hartford's Director of Development Duane Martin said there's another factor: how the town was built.
"The town was developed rather rapidly. After World War II, there was a lot of subdivision construction that went on and before the 1960s, a lot of it went unchecked," said Martin. "With regards to storm drainage, you were just allowed to have water run off the property and into the street."
Regulations are tighter these days, and municipalities are required to get a specific stormwater permit from the Department of Energy and Environmental Protection (DEEP).
“So it's basically trying to reduce the amount of storm water that's getting into that storm water system in the first place," Dietz said. "The changing storm frequency aside, as we've built up Connecticut, which has happened substantially over the last 30 years, we are adding much more water much faster and larger quantities of it to our rivers at the same time."
Following the culvert study in 2018, West Hartford conducted a two-phase drainage study to identify the extent of the deficiencies in the storm drainage system that lead to street and basement flooding. Phase II wrapped up in late 2021.
The good news for Restelli is that his neighborhood is first on the list for improvements. The bad news is that it's going to take time.
"To be conservative, I'm estimating about two years from now we should be starting construction," Martin said.
It's also not cheap - the project has an estimated price tag of $120 million. Martin said he has applied for some grants and he's hopeful the town will be able to use some of the federal coronavirus relief funds.
A storm water authority could also help offset those costs. Like other utilities, property owners are charged a fee based on how much storm water they contribute to the system.
"It's usually a pretty small amount, relatively speaking. But in aggregate, it can generate a fair amount of money that can allow the city to update that infrastructure and keep their whole city safe," Dietz said.
New London has the only municipal storm water authority in the state. The program brings in about $1.3 million a year.
Martin said it's something West Hartford is considering.
“I think it has merit. It depends on how it’s structured and how it's managed,” he said. "This flooding isn't going away. It's a big challenge for a lot of communities. And it's difficult to address, it's very expensive."
