January 2026
The New Hampshire Department of Environmental Services (NHDES) Dam Bureau is currently conducting a program to assess all State-owned dams for their ability to withstand a 1,000-year storm event. As part of this effort, NHDES has identified the Jones Dam for removal and the Merrymeeting Lake Dam for repairs and modifications.
Removal of the Jones Dam would alter the flow and volume of the Merrymeeting River and significantly reduce the extent of surrounding wetlands. Additional analysis is still required by the State to fully evaluate the ecological and hydrologic impacts of this removal before any final decisions are made.
With respect to the Merrymeeting Lake Dam, the NHDES has indicated that it anticipates initiating a lake drawdown in the fall of 2030 to facilitate repairs and modifications. Under the current proposal, the lake would be lowered approximately 20 feet for at least one year, and potentially two to three years, depending on construction progress and weather conditions.
A 20-foot drawdown would reduce the lake’s surface area from 1,233 acres to approximately 775 acres – a reduction of nearly 40%. As illustrated in the lake contour map, most areas within the yellow 0–20-foot contour band would be exposed lakebed during the drawdown period. The entire shoreline would be dry at varying widths, with the most extensive exposure occurring in the East End, Pleasant Cove, and Elly Cove.
The ecological and economic consequences of a one-to-multi-year drawdown of this magnitude would be substantial and long-lasting. Ecological impacts would include loss of critical habitat for wildlife (such as nesting loons), disruption of the warm water fishery, and impacts to insects and organisms living within lake sediments. Algae and microscopic plankton populations would be disturbed, increasing the risk of harmful blue-green algae blooms. Native aquatic vegetation on the dry lakebed would die off and be replaced by terrestrial vegetation, and when the lake is refilled, decomposing vegetation in the lakebed would create mucky, nutrient-rich sediments that favor invasive aquatic plants, such as milfoil. The lake’s ecosystem may not fully recover to the high water quality conditions of today.
The impacts to recreation, local businesses, and residents would also be substantial. Facilities such as the Merrymeeting Marina, Water Monkey Camp, and Camp Pride could face partial or complete operational shutdowns. The town beach would likely be unusable. Shorefront properties with shallow wells or lake-fed water systems could lose access to potable water, potentially compromising water supply access and requiring costly mitigation measures, such as well drilling. Boat access, docking, and most recreational uses of the lake would be severely limited – or impossible – during the drawdown period.
Additionally, the wooded knolls surrounding the dam (areas the Merrymeeting Lake Association worked hard to protect for years) could be altered or removed to accommodate expanded dam infrastructure, including a wider spillway, equipment buildings, and paved access. Protecting this area of visual significance to the community would require careful planning and construction methods to minimize disturbance to surrounding trees and landscape.
Importantly, a prolonged 20-foot drawdown may not be the only viable approach. Alternative engineering and management strategies, such as the use of a cofferdam, could potentially reduce the depth and duration of lake level reductions while still meeting safety and regulatory requirements. The MMLA has not yet seen documentation showing how broader ecological and economic impacts were evaluated alongside cost considerations in the current engineering plan.
The Merrymeeting Lake Association Board of Directors is actively working on multiple fronts to advocate for approaches that preserve and protect the lake’s innate beauty, pristine water quality, ecological integrity, and long-term value. Some actions taken so far include:
- Engaging a lobbyist to educate and advocate within the State Legislature
- Communicating with the DES Commissioner to share concerns, understand the current plan considerations, and explore potentially less impactful options
- Working closely with NH LAKES to stay informed about emerging issues that could affect our Lake
- Learning from other lake associations that have recently gone through dam repair projects
- Reviewing options for independent technical reviews of the dam and the proposed repair approach
- Established liaison with the Town & Select Board to keep local leaders informed and aligned
- Organizing the internal Dam Committee and processes to maintain forward momentum
- Providing consistent updates to members and the community
This effort will require informed, collaborative support from our members and the broader New Durham community as we work to engage constructively with the State and advocate for the long-term protection of Merrymeeting Lake. We welcome suggestions, expertise, and connections that members may be willing to share as we navigate this challenge together.
Stay engaged as this project moves forward:
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Additional Resources:
To view the initial NHDES investigation and assessment report, click here.
To view a full copy of the 12/3/25 NHDES presentation slides, click here.
To view the replay video of the 12/3/25 NHDES meeting, click here.