N.Y.C. Admin. Code § 3-508: § 3-508 Excavations or embankments near landmarks.

It shall be unlawful for any person to make any excavation or embankment, or to lay or move any pavement or flagging, within three feet of any monument or bolt, which has been set by proper authority, or designated on any official map as a landmark to denote street lines within the city, unless a permit therefor has been obtained from the president of the borough in which such monument or bolt is situated. Applications for such permits shall be in writing, and shall set forth the nature of the work proposed, and the location of all monuments or other landmarks affected thereby. The borough president shall thereupon cause one of the city surveyors or an engineer in the borough president's office to take such measurements and field notes as may be necessary to restore such monuments or bolts to their correct position after the completion of the contemplated work, and, when such measurements and field notes have been taken, the required permit shall be issued.