N.H. Admin. Code Env, Env-Wr, app C
RSA 482:2
I. "Classification of a dam" means the potential hazard classification placed on a dam by the department based on the potential threat to life and the potential extent of property damage in the event of accidental damage to, or failure of, the dam structure. The classifications shall be "non-menace," "low hazard potential," "significant hazard potential," or "high hazard potential."
II. (a) "Dam" means any artificial barrier, including appurtenant works, which impounds or diverts water and which has a height of 6 feet or more, or is located at the outlet of a great pond. A roadway culvert shall not be considered a dam if its invert is at the natural bed of the water course, it has adequate discharge capacity, and it does not impound water under normal circumstances. Artificial barriers which create surface impoundments for liquid industrial or liquid commercial wastes, septage, or sewage, regardless of height or storage capacity, shall be considered dams.
(b) An artificial barrier at a storm water detention basin, which impounds 0.5 acre-foot or less of water during normal conditions, shall not be considered a dam unless its height is 10 feet or greater or its maximum storage is 6 acre-feet or greater.
V. "Dam in disrepair" means a dam which is a menace to public safety and is incapable of safely impounding flood waters to its crest, or is incapable of maintaining a reasonably constant level of waters impounded, or is one which does not contain adequate gates and sluiceways to provide for the holding or controlled discharge of waters impounded.
VI. "Emergency action plan" means a written document delineating a prescribed sequence of actions to be taken by a dam owner to inform the authorities and others downstream of an impending or actual sudden release of water caused by an accident to, or failure of, the dam. This plan shall be developed in consultation with local officials and notification of the plan shall be given to the general public who would be affected by a sudden release of water caused by an accident or other failure of the dam. The plan shall be kept on file with the local emergency management director and other local officials as deemed appropriate by the department.
VII. "Mills" shall include both manufacturing plants and plants at which electric power is generated for public distribution or for the operation of mills, railroads or public utilities.
VIII. "Person" means any individual, partnership, association, corporation, company, organization or legal entity of any kind.
X. "Reconstruction" means:
(a) A change in the height, length, or discharge capacity of the structure;
(b) Restoring a breached dam or one in ruins;
(c) Modification of flashboards which either increases their height or increases the headwater elevation at which the flashboards will fail; or
(d) A change in the structural configuration of a dam.
N.H. Admin. Code Env, Env-Wr, app C