Heavy Rain, More Severe River Flooding In A Warmer Rhode Island

Apr 3, 2014

Decades of development along floodplains and on wetlands in Johnston have made the town vulnerable to severe flood issues. Scientists say climate change may make these floods even worse, with more frequent and intense storms. A couple families that have long dealt with floods year after year will soon get relief, as federal money is available to buy out and demolish these properties in flood zones in the Pocasset River watershed.

Paul Prendergast reviews photos of the flood damages to his home he has documented over the years.
Credit Ambar Espinoza / RIPR

Paul Prendergast was 24 years old when he built his house in Johnston on a new development next to the Pocasset River. Living next to the river was a big draw for Prendergast. But the river's peace and calm was short-lived.

“Within 6 months of moving in, I knew I had made the biggest mistake of my life when we had our first flood issue,” said Prendergast. “It was Super Bowl Sunday 1979.”

Local papers referred to this flood as "The Great Flood of '79" with nearly a million dollars in damages and 250 water emergencies reported by the local fire department.

Since then, Prendergast averages two floods each year. The floods have gotten worse over the years. There’s a reason why his land floods.

“I learned later that my developer was my former town administrator and through some method, he purchased the land and it became developable all of a sudden,” said Prendergast.

The land wasn't developable simply because it was a floodplain, the area of land next to a river or stream that stores and regulates floodwaters.

Prendergast couldn't sell his house knowing it sits on a flood zone. So he tried to make it as livable as possible. He closed off the garage door and converted it into a family room, hoping that a solid wall would act as a dam. He added pumping stations in the basement and built a garden stonewall around his house. None of these changes were enough to keep the river waters out during a flood in 2005. The basement was in 4 ½ feet of water. Now it’s nearly empty.

“We lost couches, chairs, a daybed, piano, all floating around,” said Prendergast. “That's happened twice. You might hear the echo in here because of how empty it is. We just don't use it.”

Sometimes, Prendergast doesn't use the garage he added to his house. Depending on the weather forecast, he'll park his car up the hill during heavy rainstorms. It's become a routine.

“And that takes a toll,” said Prendergast. “That level of anxiety is very taxing… to get calls from my now ex-wife that the water is coming up, ‘What do I do?’ She doesn't know how to turn off the gas and turn off the electricity and all the things that you have to do, so I think in a large part, this issue contributed greatly to our divorce. She just couldn't take the anxiety anymore.”

Relief from a federal emergency watershed program
But relief is on the horizon. Federal emergency money flowed into the state for the devastating damages caused by the Big Flood in March of 2010, a state-declared disaster. Some of that leftover money from an emergency watershed protection program will benefit Johnston.

“Thank goodness for this extra money that a community didn't use, they're going to transfer it here,” said Johnston mayor Joseph Polisena. He said the Natural Resources Conservation Service (NRCS), a division of the U.S. Department of Agriculture, relocated a few of Prendergast’s neighbors away from the river back in 2010. The NRCS has $1.7 million left over to buy out a couple of more homes, demolish them, and restore that land back to what it used to be: low, flat grassy land next to the river.  

"This way when the Pocasset fills up, the water will go on to that property and hopefully, it acts like a reservoir,” said Polisena. “It slows it down from going into Cranston and flooding out Cranston. So what happens is, it allows the water to fill up on the banks or the property itself.”

The Pocasset River begins in the northwestern part of Johnston, flows southeast through town, under I-295 and along other highways, until it eventually flows southeast into the city of Cranston.

The impact of development amplified by climate change
In 2001, the NRCS estimated that more than 600 acres of wetlands in the Pocasset watershed were destroyed from the late 1930s to the late 1990s to develop Johnston and Cranston. It cited this information in a 2006 study of the Pocasset watershed.

Chuck Horbert, a supervising scientist with the Department of Environmental Management's freshwater wetlands program, said development has filled in areas of wetlands and floodplains that would normally store floodwaters.

All that concrete it takes to build parking lots and strip malls has also increased hard surfaces that don't allow rain to soak through the way natural ground would. Horbert said much of the development happened before strong wetland and flood protection regulations.

"Over the years with climate change, you're simply getting larger, more intense rainfall events, as well as more rain events and higher volumes of rainfall in these areas," said the DEM's Chuck Horbert.

“Now what has happened, even though we have these protections in place, there are still projects occurring—that don’t need DEM approval—that are contributing runoff to these areas,” said Horbert. “And over the years with climate change, you’re simply getting larger, more intense rainfall events, as well as more rain events and higher volumes of rainfall in these areas.”

Horbert said it used to take 7 inches of rain within 24 hours to define a 100-year storm. Now it takes nearly 9 inches, which is a change reflected in the DEM's stormwater manual for Providence and Kent counties.

Unless steps are taken to better manage storm water, Horbert said floods could continue to get worse in densely developed areas that have lost natural spaces to soak up or store all that extra rain that has caused significant damages in places like Johnston, Cranston, and Warwick.

The small pool of money available for Johnston is enough to remove two to three properties, even though more properties qualify for help.

Johnston resident Paul Prendergast couldn’t be more grateful for the chance to let go of his flood-ridden house. He’s eager for the project to take off.  So where does he see his new home?

“I can guarantee that I will be high up on hill somewhere hopefully overlooking a lake or something,” said Prendergast.

Flooding in areas like Johnston and Cranston will likely become even worse, as climate change brings more extreme weather. The USDA thinks protecting wetlands and putting up a flood wall along the Johnston-Cranston border would reduce flooding in some properties. But it doesn’t have money for those projects either.

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