N.H. Rev. Stat. § 38:18
For the more convenient management of any such electric, gas, or water works system, any such municipality may vest the construction, management, control, and direction of the same in a board of commissioners to consist of 3 or more citizens of such municipality, the commissioners to have such powers and duties as the municipality may prescribe. Their term of office shall be for 3 years and until their successors are elected and qualified. The first board of commissioners may be chosen for terms of one, 2, and 3 years, respectively, by the legal voters of the municipality at any legal meeting or election at which the provisions of this chapter are accepted, or at any special meeting or election thereafter called for that purpose, and their successors shall be elected at each annual meeting or election thereafter in the manner or form as the municipality may determine.
RSA 38:18
1997, 206:1, eff. July 1, 1997.