N.Y. Environmental Conservation Law § 15-2315

§ 15-2315. Unlawful interference with improvement works.\n It shall be unlawful for any person to damage, alter, change or\ninterfere with any works constructed under the provisions of title 23 or\nto open or close, or cause to be opened or closed, a gate or gates in\nany dam or dike or a gate in any head race or obstruct any channel\nconstructed under title 23 so far as the same relates to such\nimprovements, without the consent of the department. After the\nimprovement of any channel or watercourse has been authorized it shall\nbe unlawful for any person or public authority to construct any dam or\nother structure on the bed of such stream or any bridge across it until\nthe department has found that such construction or bridge will not\nunduly affect the projected or completed improvement.\n