Jones Pond Dam
Due to concerns raised by stakeholders in the communities of New Durham and Alton, the New Hampshire Department of Environmental Services (NHDES) has consulted with the New Hampshire Fish and Game Department (NHFG) and will be postponing the previously planned spring 2026 drawdowns of Jones Dam and Alton Power Dam. The revised schedule now anticipates initiating the drawdowns in September 2026.
This postponement will provide additional time during the spring and summer months to collect additional information within the impoundments and downstream reaches of the Merrymeeting River. NHDES and their engineering consultant will be performing data‑gathering activities throughout the summer season. Residents should expect to see personnel in and around the river system as this work proceeds.
Although NHDES does not anticipate manipulating stoplogs or opening gates this spring or summer, it is important to note that significant storm events may still require operational adjustments. As in the past, if necessary to properly pass flows and maintain safe conditions, NHDES may temporarily remove stoplogs or open gates at either dam until water levels return to normal operating ranges.
NHDES will work with the local selectboards to attend meetings in New Durham and Alton during the summer of 2026 to discuss the findings of ongoing sampling and monitoring efforts. These meetings will also include a review of the procedures for implementing the controlled drawdowns in September.
Consistent with prior plans, once the impoundments are drawn down in September 2026, they will remain in a lowered condition, approximately 2.5 feet at Alton Power Dam and approximately 4.5 feet at Jones Dam relative to their current elevations. These lowered conditions will remain in place until the dams are either rehabilitated or removed, as determined through ongoing engineering and environmental evaluations. However, NHDES may temporarily lower the impoundments below these elevations in September, if needed, by operating the low‑level gates to support additional data collection.
NHDES will continue coordinating closely with NHFG, local officials, and community stakeholders and will provide additional updates as new information becomes available.
Thank you,
Corey J. Clark, P.E.
Chief Engineer
NH Department of Environmental Services
Water Division
Dam Bureau
29 Hazen Drive, PO Box 95
Concord, NH 03302-0095
Tel: (603) 271-1961
Fax: (603) 271-6120