N.H. Rev. Stat. Ann. § 482:1

The general court declares that there is a statewide need for conservation and control of water in streams, rivers, lakes and ponds by the repair of dams now in disrepair, the construction of new dams, the construction of hydro-energy production facilities as defined in RSA 481:2, IV, and stream clearance and channel improvement. These actions are needed for the regulation of the water levels of lakes and ponds, the flow of water for fire prevention, protection to lessen flood damage, the enhancement of public safety, the improvement of recreational facilities within the state, and for any similar public purpose.