Norwich ― About 500 Norwich residents and a dozen Bozrah businesses were ordered evacuated Wednesday after defects were discovered in a Bozrah dam on the Yantic River, as the river caused major flooding in Norwich.

At 4 p.m. the evacuation order was lifted and Bozrah firefighters planned to remain at the dam to monitor it through the night.

A deluge of rain caused near-record flooding of the Yantic River, inundating streets, businesses and homes, requiring emergency boat rescues at two businesses and closing several streets throughout the day.

Norwich Public Utilities shut down a power substation in the flooded Bean Hill section that serves more than 5,000 customers. As of 5 p.m. on Wednesday, power has been restored to all NPU customers that were impacted by the storm.

Norwich was the community hardest hit by the wind-driven rain storm in southeastern Connecticut. Other towns and cities in the region reported their own road closures, especially in flood-prone areas. In Mystic, portions of Gravel and Pearl streets were closed due to flooding. During the height of the rainstorm areas of Bank and Broad streets in New London were impassable. Water had receded from many of the areas by mid-morning, after the rain stopped. Area schools also reported late openings or closures on Wednesday.

Earlier Wednesday, Norwich officials issued a mandatory evacuation order for about 500 residents and businesses in the Yantic River flood zone from the Bozrah border to Uncas Leap at Yantic Falls on Yantic Street due to concerns that the Fitchville Pond Dam on the Yantic River in Bozrah could fail.

About a dozen businesses in Bozrah also were under an evacuation order, First Selectman Glenn Pianka said.

Gov. Ned Lamont and several state and local officials joined officials from the state Department of Energy and Environmental Protection at a news conference Wednesday afternoon at the Fitchville Pond Dam, located at Fitchville and Stockhouse roads in Bozrah.

Dam has a potential for failure

Chuck Lee, assistant director of dam safety for DEEP, which maintains an inventory of dams in the state, listed the structure as a Hazard Class C- or “high hazard potential,” the worst of five categories that indicate the potential for a dam failure.

State officials said the dam is owned by Seymour’s Sand and Stone of Bozrah. The owner has a history of not complying with state regulations to inspect the dam every two years and to file an action plan for emergencies, Lee said. The dam has no action plan at present.

Defects were discovered at about 5:30 a.m. Wednesday, when a Norwich official discovered that water was leaking through the left abutment of the dam, spilling onto Fitchville Road. Lee said inspectors had not seen that happen before.

The DEEP called the engineer who inspected the dam in 2022 and began planning for the evacuation order as a precaution.

Lee said a contractor was hired to create a cofferdam by placing giant sandbags in the water behind the dam to create a second dam, drying the dam area to relieve water pressure and allow inspectors to examine the structure.

At the state’s direction Wednesday, Seymour Adelman, the owner of Seymour’s Sand and Stone, dumped a pile of stones up against the leaking wall of the dam for extra support.

State officials said decisions about possible enforcement action against the dam owner, including reimbursement for the cost of the emergency response, would be made after the emergency subsides.

Adelman could not be reached to comment late Wednesday afternoon.

The stone and concrete dam was built in the 1840s and was upgraded in the 1880s, Pianka said. The dam helped power the Palmer Mill, now gone, and a stone mill that had stood at the edge of the dam. That mill was washed away and destroyed in the 1938 hurricane, Pianka said.

Norwich flooding reached record levels

Norwich City Manager John Salomone emphasized that the extensive flooding in Norwich on Wednesday morning throughout the Norwichtown and Yantic areas was not caused by the dam. The Yantic River frequently floods during heavy rains, and the river level reached near historical record levels Wednesday.

The river reached 14.2 feet in Norwich at 8 a.m., approaching the all-time record of 14.9 feet. Minor flood stage is 9 feet. The level dropped to 12.3 feet at 11 a.m., but Riley said the concern remains about the Fitchville Dam and the forecast for more rain this weekend.

Thomas Main, Bozrah’s director of emergency management, said huge amounts of water have been flowing over the dam, leading to flooding downstream. Main said the water, as of 10 a.m. had already receded by a foot and a half.

Twitter

The state Department of Emergency Management and Homeland Security, at the request of the town of Bozrah, has issued a precautionary evacuation of Stockhouse Road over concerns of flooding near the Fitchville Pond Dam.

Main said officials from DEMHS and DEEP continued monitoring the dam throughout the day Wednesday.

Norwich schools were ordered closed after initially plans for a two-hour delay.

NPU spokesman Riley said the area around the Bean Hill substation was flooded, and the substation had to be shut down until utility crews can reach the area to determine whether the system is inundated with water. It resumed operation late Wednesday afternoon.

Numerous Norwich streets were closed or had water flowing over the surface, and flooding from the Yantic reached businesses along Town, West Town and Sturtevant streets and Otrobando Avenue. Water reached the door at Stop & Shop Supermarket, which placed sandbags to keep the water from entering the store, Norwich City Manager John Salomone said.

c.bessette@theday.com