Darien Selectmen Receive Update On Grove Street Flood Study Results

DARIEN, CT — As the intensity of storms continues to increase, the town of Darien is taking action.

On Tuesday during the regularly scheduled Board of Selectmen meeting, Director of Public Works Ed Gentile presented results from the Grove Street Flooding Study, the third in a series of studies aimed at improving infrastructure and flooding in town. The study was originally completed in April.

The study area included almost all of the downtown area between the railroad and Interstate-95. The Grove Street Plaza, Tilley Pond Park and West Avenue areas were heavily impacted by flooding in 2021 in Tropical Storms Elsa and Ida.

"The study detailed increasing precipitation depth and frequency, which means the storms are becoming more intense. They're not slowing down," Gentile said. "Current findings indicate that multiple sections upstream of the Boston Post Road as well as under the railroad tracks are undersized. There are multiple choke points along this system, with inconsistent pipe sizes."

Gentile noted that the study showed some opportunities for improvements so the town can upgrade the drainage/piping system and promote resilience for the downtown area.

"I think the idea here is to look at some of the larger storms and see if we could minimize the impact of flooding. You're never going to eliminate flooding, but you can possibly direct it or change it," Gentile said.

Multiple plans were considered by the firm Tighe & Bond, but "Alternative No. 8" was recommended.

"One of the big changes for this is to re-run pipe underneath the railroad, down Day Street and across the Center Street North parking lot and out to Old Kings Highway South and put in a secondary discharge [to Goodwives River]," Gentile said.

The existing drainage system would remain functional, too. There would be a significant improvement in roadway flood depth over 25-year and 50-year storm events, evidenced by the colorful circles in the graphic above.

"You'll have dual systems now, and that's what you need to correct this flooding," Gentile said.

First Selectman Monica McNally thanked Gentile for his work on the study.

"I particularly appreciate addressing downtown flooding. I think that impacts everyone," McNally said.

The Opinion of Probable Construction Cost (OPCC) associated with Alternative No. 8 is $3.4 million, according to Gentile's presentation.

McNally asked if the town had Gentile's assurance that he would explore opportunities for grant money to help fund the flooding/drainage projects the town is undertaking.

"We're working on that right now for Salt Box, and once I get this thing off the ground, we'll address it the same way," Gentile said.

Gentile noted that the process could be lengthy before improvements can begin. Obtaining permits and an easement are projected to take months to complete.

"I appreciate all the work on this, and I'm looking forward to the design phase," McNally said.

You can view Gentile's presentation on DarienTV79. The presentation begins at the one hour, 20 minute mark.