skip navigation
New Hampshire Department of Environmental Services


The NH Department of Environmental Services (NHDES) is authorized to maintain the Official List of Public Waters (OLPW) per RSA 271:20. This document lists great ponds and artificial impoundments of 10 acres or more in the State of New Hampshire.

In the Official List of Public Waters, great ponds are identified as "NL" (natural lake) or "RD" (natural lake raised by damming). The State owns the beds of all great ponds, up to the elevation of natural mean high water (NMHWM). NHDES has determined the NMHWM elevations at a few of New Hampshire's great ponds. This data is subject to continuous review.

Artificial impoundments 10 acres or more in size are identified with the status of "AI". Water bodies with the "AI" designation are not defined as great ponds because they were less than 10 acres in size before the construction of a dam.

Dam Bureau staff are available to answer questions from the regulated community and the public concerning the New Hampshire Dam Bureau Rules and compliance issues which affect dams, their impoundment and their downstream reach. We are available Monday through Friday, 8:00 AM to 4:00 PM at (603) 271-3406 or

The Dam Bureaus activities are governed by RSA 482 and NH Code Admin. Rules Env-Wr 100-800.

NH Department of Environmental Services | 29 Hazen Drive | PO Box 95 | Concord, NH 03302-0095
(603) 271-3503 | TDD Access: Relay NH 1-800-735-2964 | Hours: M-F, 8am-4pm

copyright 2017. State of New Hampshire