N.Y. Navigation Law § 80: Three feet depth to be maintained

§ 80. Three feet depth to be maintained. Whenever a municipal

corporation shall divert or cause to be diverted the water, or a portion

thereof, of a fresh water stream or streams outside the limits of an

incorporated city flowing into a tidewater creek or estuary which

tidewater creek or estuary before such diversion was navigable for

vessels of twenty or more tons burden, it shall be the duty of the

corporation so diverting or causing to be diverted such stream or

streams of fresh water to keep said navigable tidewater creek or estuary

deepened to the depth of at least three feet at low water mark from its

mouth to the head of tidewater for the full natural width of said creek,

and to maintain such navigable depth of water at all times, but in the

county of Nassau it shall not be compulsory to maintain such depth to

any greater width than fifty feet.