The Norwalk Department of Public Works identified typical trouble spots for flooding during storms and high tides in anticipation of Tropical Storm Henri. Crews placed barrels and sawhorses near these locations to make road closures quick. Erik Trautmann / Hearst Connecticut Media

CT - South Norwalk streets should be raised by 3 feet due flooding and climate change, experts say

NORWALK — Streets in South Norwalk must be raised by at least 3 feet to prepare for future storm surges in 2050, experts with the Connecticut Institute for Resilience and Climate Adaptation report.

“Places that use to flood every 20 years are going to flood every five years,” said John Truscinski, director of resilience planning at CIRCA.

During the Ad Hoc Sustainability and Resilience Committee of the Common Council on May 17, Truscinski outlined ways the city could address the flooding issues South Norwalk faces now and will likely face in the future. South Norwalk is one of seven coastal cities selected by CIRCA for climate mitigation planning.“We wanted to look at which of the roads are going to flood and how high would we need to elevate them to prevent them from flooding under these different scenarios,” Truscinski said.  

In major storms like Hurricane Sandy, South Norwalk can see typically 4 1/2 to 5 feet of storm surge, which causes major flooding throughout South Norwalk. CIRCA projects that the Long Island Sound will rise 20 inches by 2050 due to climate change, which would worsen the issue.

“We get those [storms] like every 20 to 25 years when we look back at the last 100 years, those are kind of the big floods,” Truscinski said. “But when we add sea level to Long Island Sound, it doesn’t take the big storms to produce that same water level. So that’s the problem, so those types of floods are going to happen more frequently.”  

Raising the street level

A majority of the streets in South Norwalk are about 7 feet above the sea level and high tide is about 3 1/2 feet. When flooding occurs, major transportation routes like Water Street and Woodward Avenue are submersed, leaving people stuck in their homes and blocking first responders from reaching those in need.  

CIRCA outline solutions the city can take to combat this issue, including raising the road by 3 feet so they are 10 feet about the sea level. Truscinski explained other coastal cities like Miami have begun doing this to prepare for the effects of climate change.

“Which of these key transportation connections are likely to experience different types of flood impacts in the future and what are the potential options to adapt these corridors over time to make them more resilient to climate change? And so, that’s a big focus of what we’re doing,” Truscinski said.

Officials did not detail the engineering and construction work that would be needed to elevate the roads. But raising the street is more complicated in dense areas like South Norwalk because all the driveways and roadway feeding onto the main road will need to connect to the new height. Truscinski said Day Street would likely be easier to raise than Water Street because there are fewer buildings and part of Day Street has already been raised.

Other solutions

Truscinski said addressing Norwalk’s draining system issues and installing more green infrastructure should also be a priority for the city.

“I think the main thing is that whatever exists, whatever goes there, whatever development happens there is going to have to be able to withstand that frequency of flooding and so that is something the city’s got to think through and figure out how to redesign, adapt those sites to accommodate that increase in the frequency,” Truscinski said.

One potential solution discussed in the meeting is to develop a resilience zoning overlay and create design guidelines for all new developments in South Norwalk. Norwalk is undergoing a rewrite of its entire zoning code for the first time in decades.

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