Granite Lake Dam

About Granite Lake Dam

The primary purpose of Granite Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Granite Lake Village District (local government). It impounds the Granite Lake Brook near Nelson.

The dam stands 11 feet tall and stretches 90 feet across, creates a reservoir covering 211 acres, has a maximum storage capacity of 990 acre-feet, and collects water from a drainage area of 4 square miles. Completed in 1814, the structure is one of the older dams in the region, with over a century and a half of service.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 06/10/2021.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The New Hampshire dam safety program can provide more specific information about emergency planning for this structure.

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