N.J. Stat. § 48:19-17
Each water company may lay its pipes beneath such public roads, streets, and places as it may deem necessary for its corporate purposes, free from all charge to be made by any person or body politic whatsoever for such privilege, and may also construct and maintain hydrants on and along such roads, streets and places, provided that the pipes shall be laid at least 3 feet below the surface and shall not in anywise unnecessarily obstruct or interfere with the public travel or damage public or private property.
The consent of the public body charged with the repair and maintenance of such public roads, streets and places shall first be obtained.
If such public body shall refuse or fail to give its consent, the water company may appeal to the Board of Public Utility Commissioners of the State of New Jersey. A hearing thereon shall be had on notice to all parties in interest, who shall be afforded an opportunity to be heard. If, after such hearing the Board of Public Utility Commissioners shall determine that the installation of such pipes or hydrants is reasonably necessary for the service, convenience or welfare of the public, the water company shall be authorized to proceed in accordance with such determination.
N.J.S. § 48:19-17