Nissequogue River listed among nation's most endangered

The Nissequogue River was named one of the 10 most endangered rivers in the United States by the conservation group American Rivers because of a plan to rebuild a dam in Blydenburgh County Park that would block  2 miles of free-flowing water.

The Washington, D.C.-based group each year releases a most endangered list based on impending decisions that could damage the river’s ecological health; its importance to wildlife, nature and people; and the degree of the threat.

“Rebuilding the dam would reverse recent gains for the river and communities by disrupting fish passage, degrading water quality, trapping sediment, warming the river, eliminating valuable flood plain, and reducing the flood plain’s capacity to manage stormwater,” American Rivers' report said. 

Advocates for the dam have argued the Blydenburgh pond had been a community hub that existed for more than 200 years and was a favorite spot for kayaking, canoeing and bass fishing until the dam failed in a heavy storm in August 2024. 

In the 20 months since, the river has established a meandering path through the once-submerged flood plain. By the end of last summer, nearly 100 native grasses and wildflowers had spread across the muddy pond floor, according to a botanist’s survey. Birders have reported more diverse species visiting the park since the 118-acre meadow emerged.

"The Nissequogue is the most ecologically important river on Long Island," said Sara Cernadas-Martín, the director of Save the Sound's ecological restoration program in New York, who noted the river system "is already recuperating at an impressive pace."

At a Suffolk County Legislature meeting last month, several park enthusiasts spoke in favor of a new dam. Rich Scatoni, a Smithtown resident, acknowledged the flush of growth in the former pond basin but said thousands of visitors had enjoyed Stump Pond.

"There is no substitute for a 100-plus acre body of water,” he said. 

The Suffolk planning department concluded flooding the meadow would have no significant environmental impact. On March 10, the legislature voted to allow the project to proceed without a full environmental impact assessment, in spite of the state Department of Environmental Conservation’s recommendation that a study was warranted.

Legis. Leslie Kennedy (R-Nesconset), a dam proponent, told Newsday she was persuaded by the experts she consulted that a dam would protect downstream residents from flooding.

A coalition of 19 local, state and national environmental groups have argued an open, absorbent flood plain offers superior protection from the heavy rains that will arrive more frequently with climate change.  

The Nissequogue was seventh on the most endangered list. Others on the list include the San Joaquin in California, which is threatened by a gravel mine; the Lumber River in North Carolina, burdened by toxic PFAS pollution; and the Chilkat, which flows through traditionally Native territories in Alaska and is threatened by a copper mine.