N.Y. Pub. Lands Law § 28
The commissioner of general services may, with the concurrence of the mayor of the city of New York, transfer and convey to the city of New York, in consideration of one dollar to be paid to the state of New York and upon such other terms and conditions as agreed upon by such commissioner and the mayor of the city of New York, parcels of land or watershed conservation easements owned by the state and located within the counties of Dutchess, Putnam, or Westchester and within the watershed of the water supply of the city of New York, whether or not such parcels or watershed conservation easements are unappropriated state lands, for the purpose of protecting the water supply of the city of New York. The city of New York may, with the prior agreement of the commissioner of the department of health, transfer and convey any such parcels for the sole purpose of purchasing lands in areas of higher priority for water supply protection purposes, provided that the city of New York shall either (1) transfer and convey to the state of New York, in consideration of one dollar paid to the city of New York, any such parcels provided that the city of New York continues to pay real property taxes on any such parcels and upon such other terms and conditions as agreed upon by the commissioner of general services and the mayor of the city of New York; or (2) sell any such parcels to an entity other than the state of New York and provide to the state of New York monies equal to the original purchase price paid by the state of New York for such parcels. For purposes of this section, the term "watershed conservation easement" shall have the same meaning as defined in section five hundred eighty-three of the real property tax law.
N.Y. Pub. Lands Law § 28