‘Don’t take down the dam’: Some Ridgefield residents oppose Norwalk River watershed plan

Photo of Alyssa Seidman

RIDGEFIELD — A number of Ridgefield residents spoke at a public meeting on Tuesday night to oppose the potential decommissioning of the Great Swamp Dam near Fox Hill Condominiums on Danbury Road.

Representatives from the U.S. Department of Agriculture’s Natural Resources Conservation Service shared plan details with roughly 40 stakeholders at the Ridgefield Recreation Center, which lies just downstream from the dam.

The dam is located in Ridgefield’s Norwalk River watershed and was constructed by the Natural Resources Conservation Service in the late 1970s as a flood-control measure. At the meeting, representatives said the purpose of decommissioning the dam is to make it compliant with federal regulations.

“This dam is not at imminent risk of failure, but the conditions surrounding the dam have changed,” said Tom Morgart, state conservationist for the Natural Resources Conservation Service.

In 2004, the dam was reclassified from significant hazard potential to high hazard potential due to the possible threats to life, property and infrastructure in the event of a potential breach. Recent hydrologic studies estimate, however, that if such an event occurred, up to 24 people could be killed downstream — 16 motorists, three residents in one house and five people in one business.

The service said if the dam is decommissioned, its threat to residents would be reduced in the event of a “100-year storm.” The cost of decommissioning ($857,100) is substantially lower than the cost of structural rehabilitation ($6.5 million). The service and the state Department of Energy and Environmental Protection, which owns the dam, would be responsible for the costs.

If DEEP decides to move forward with the service’s plan, engineers would remove the dam embankment as well as its principal spillway and armor the restored stream channel. Additionally, a concrete cutoff wall would be installed to prevent channel down-cutting and maintain the water and sediment capacity of the Great Swamp wetlands upstream.

Talks surrounding the dam recently resurfaced when the service released a report in March containing modifications to the initial project and its costs. Stakeholders, however, said they weren’t notified of that report until receiving a letter on June 3.

The agency has since moved the deadline for public comment to Aug. 20. All questions and concerns submitted in reference to the plan will be accepted until then and addressed in the final report.

The residents who spoke at Tuesday’s meeting were unconvinced the dam should be removed. Some took issue with the service’s probable maximum flood index. According to the report, the existing dam would not pass the probable maximum flood of 33 inches without overtopping.

“The most rain that the state of Connecticut ever received over a 24-hour period was 12.7 inches, and that was in Burlington,” David Pope said. “I think your baseline is totally divorced from reality.”

Former town engineer Charlie Fisher, who read all 234 pages of the service’s new report, said he would prefer the dam undergo structural rehabilitation to continue to provide flood protection from future storms.

“Previous inspections on the dam, including those conducted as part of the NRCS report, have shown that the dam is physically in good shape and has the capacity to safely pass 100- and- 500-year storms,” he said. “Until a new flood-control plan is developed for the watershed, it is strongly recommended that the existing dam not be demolished.”

Linda Massie, a 20-year resident of Fox Hill Condominiums, said, “With the need for infrastructure repairs all over the state, it seems the project is based on nothing and is a waste of resources.”

Fellow Fox Hill resident Margo McEachern agreed. “If we got 33 inches of rain [First Selectman Rudy Marconi is] going to be out there with the Coast Guard,” she said. “We need bridges built and roads fixed. … Don’t take down the dam.”

A copy of the plan is available at the Ridgefield Library and on NRCS website. Information on submitting feedback on the plan can also be found on the NRCS website.