N.Y. Gen. Mun. Law § 412

§ 412. Use of revenue of undertaking. Any municipality issuing bonds\nfor the acquisition, construction, reconstruction, improvement,\nbetterment or extension of an undertaking shall have the right to\nappropriate, apply or expend the revenue of such undertaking for the\nfollowing purposes: (a) to pay when due all bonds and interest thereon,\nfor the payment of which such revenue is or shall have been pledged,\ncharged or otherwise encumbered, including reserves therefor, (b) to\nprovide for all expenses of operation and maintenance of such\nundertaking, including reserves therefor, (c) to pay and discharge\nnotes, bonds or other obligations and interest thereon, not issued under\nthis article for the payment of which the revenue of such undertaking\nmay have been pledged, charged or encumbered, (d) to pay and discharge\nnotes, bonds or other obligations and interest thereon, which do not\nconstitute a lien, charge or encumbrance on the revenue of such\nundertaking, which may have been issued for the purpose of financing the\nacquisition, construction, reconstruction, improvement, betterment or\nextension of such undertaking, and (e) provide a reserve for\nimprovements to such undertaking. Unless and until full and adequate\nprovision has been made for the foregoing purposes, no municipality\nshall have the right to transfer the revenue of such undertaking to its\ngeneral fund.\n