Drawdown Notification of Alton Power Dam and Jones Pond Dam

Drawdown Notification of Alton Power Dam, Alton and Jones Pond Dam, New Durham

The New Hampshire Department of Environmental Services (NHDES), Dam Bureau, is planning to adjust the water levels in Wentworth Pond and Mill Pond behind the Alton Power Dam beginning September 2, 2026. In accordance with RSA 482:13, NHDES is notifying the local governing bodies and the NHDES Dam Safety and Inspection Section that this drawdown will be a full drawdown to the base of the dam, lasting approximately 1–2 weeks. Following this period, the impoundment will be refilled to a level 2.5 feet below the current water surface elevation by leaving the stoplogs out of the dam.

A public informational meeting to discuss details of the drawdown and answer questions will be held at the Town of Alton Selectboard meeting on Tuesday, August 11th at 6:00 p.m., located at 1 Monument Square, Alton, NH 03809, in accordance with RSA 482:13.

Beginning September 2, 2026, the stoplogs in Jones Pond Dam will also be removed, resulting in a water surface decrease of approximately 4 to 5 feet from its current elevation. This reduction will support ongoing engineering evaluations and wetland studies within Jones Pond. The waterbody will remain in a lowered state until the dam is removed.

A public informational meeting concerning this change will be held at the Town of New Durham Selectboard meeting on Tuesday, August 25th at 6:00 p.m., located at 4 Main Street, New Durham, NH 03885, in accordance with RSA 482:13.

For more information, please contact Corey Clark, NHDES Dam Bureau at corey.j.clark@des.nh.gov or 603-271-1961.