Dam in danger of failing

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STEVE BIGHAM

ANSONIA — An ongoing effort to remove two nonfunctioning hydroelectric dams along the Naugatuck River has taken on added urgency following the results of a just-released study which found that one dam is in danger of failing.

Naugatuck Valley Council of Governments said the results of testing released last Friday indicate Ansonia’s Coe Pond Dam, a secondary dam to the larger Kinneytown Dam in Seymour, is in poor condition and, if not addressed, “poses an immediate threat to public safety with the potential for loss of human life and property damage.”

The report, based on an inspection by Gomez and Sullivan Engineers, details numerous deficiencies in the condition of dam and claims any one of them could lead to a breach of the dam at any time. It also states that a breach would inundate and damage the adjacent commuter rail line, with the potential for loss of human life and property.

The report recommends the water level in Coe Pond be lowered as soon as possible to reduce the risk of dam failure. It adds Coe Pond Dam is an “imminent public safety threat and calls into doubt its structural integrity.”

The report cites deficiencies such as significant vegetative growth on the dam, beaver activity, erosion, undermining and evidence of overtopping.

It states that a lack of instrumentation to monitor water levels means there is no ability to provide warning ahead of a breach event, or notify the railroad and utilities.

The report states the dam is classified as having “significant hazard potential,” but it should be reassigned as “high hazard.”

Coe Pond Dam is a nearly 3,000-foot earthen dam impounding Coe Pond, part of a canal and reservoir system that once delivered water from above Kinneytown Dam to a powerhouse at the southern end of Coe Pond in Ansonia.

The dam was constructed in 1845.

NVCOG engineer Aaron Budris said the owner of the dam facility, Kinneytown Hydro, has been notified of the need to immediately mitigate the threat to public safety. The state Department of Energy and Environmental Protection has emergency authority to safeguard the public by taking immediate action, as it did with Bozrah’s Fitchville Pond Dam in January.

Budris said the report’s findings have delayed the overall dam removal project because the entity slated to acquire the property, Connecticut Brownfield Land Bank, is unable to do so unless the public safety threat is addressed first.

Budris said the report further illustrates the need to decommission both dams as part of ongoing work to bring the Naugatuck River back from its former designation as one of the nation’s most polluted rivers.

“It’s a hydroelectric facility that hasn’t been operational for several years. It is not providing any benefit but is impacting the overall health of the river. It blocks access to the river and migratory fish passage, and there is the downstream risk of flooding if the dam should ever fail,” Budris said.

Just as important, the dams prevent the region from realizing the full benefits of hundreds of millions of dollars invested to improve water quality and habitat, he noted.

Three dams were removed along the Naugatuck River in Waterbury about a decade ago.

Budris said both the Kinneytown and Coe dams are federally regulated and overseen by the Federal Regulatory Commission.

NVCOG has begun engineering for the removal of the dams and subsequent restoration of the river through a $15 million grant from the National Oceanic and Atmospheric Administration. Budris said the actual removal of the dams would take place over the next three years.