N.Y.C. Admin. Code § 24-302: § 24-302 Commissioner of environmental protection; duty in regard to sources of water supply and property of department.

It shall be the duty of the commissioner to preserve the purity of all waters from which any part of the city water supply is drawn, and to protect such supply and the lands adjacent thereto from injury or nuisance. He or she shall maintain, preserve and repair all structures and all other property connected with the water supply.