N.Y. County Law § 299-M
The board of supervisors of each county may establish or extend county small watershed protection districts in the manner hereinafter provided, for the purpose of undertaking, constructing and maintaining projects and works of improvement for flood prevention, land treatment, and for the conservation, development, disposal and utilization of water including but not limited to use for irrigation in watershed and sub-watershed areas as provided for in the federal act approved August four, nineteen hundred fifty-four, and known as public law five hundred sixty-six, and as the "Watershed Protection and Flood Prevention Act", and all acts amendatory thereof and supplemental thereto, and which projects and works of improvement have been or may be approved by the federal government and for which federal financial and other forms of assistance shall be made available.
N.Y. CountyLaw § 299-M