N.Y. Nav. Law § 120

§ 120. Dams and bridges. No dam shall be erected on any river or\nstream in this state, recognized by law or use as a public highway for\nthe purpose of floating and running lumber, logs or other timber, over\nor upon the same, unless there be built in such dam an apron, at least\nfifteen feet in width, in the middle of the current of such river or\nstream, of a proper slope for the safe passage of lumber, logs and other\ntimber. No bridge shall be built over any such river or stream in such a\nmanner as to obstruct or prevent the free and uninterrupted passage of\nlumber, logs and other timber down and along such river or stream.\n