N.Y.C. Admin. Code § 3-504: § 3-504 Borough president; right of entry.

The president of any borough may enter in the day time upon any lands, tenements, hereditaments and waters which he or she shall deem necessary to be surveyed, used or converted, for the purpose of laying out, surveying and monumenting parks, streets, bridges, tunnels and approaches to bridges and tunnels or marking any boundary line or lines.