N.H. Rev. Stat. Ann. § 482-A:18

If any person places fill in the bed of public waters or below the artificially-created high water level of public-owned water bodies except as provided in this subdivision, such person shall be guilty of a misdemeanor if a natural person, or guilty of a felony if any other person. Any person may be compelled to remove the same by the superior court upon a petition brought by the attorney general.