N.J. Stat. § 48:14-12
Every steam and water power company organized under the laws of this State may cut or acquire main canals or raceways on each side of the rivers or streams from its dams to such points below as it may deem necessary. The company also may cut and erect as many lateral or branch raceways, locks, weirs, gates and other works, from the main canals or raceways to the rivers or streams as it may deem expedient for the purposes of generating, using and selling the power of the rivers and streams and electric power developed therefrom for mills, manufactories and other purposes. All work pursuant to this section shall be subject to the approval of the Department of Conservation and Economic Development.
The water so diverted from the rivers and streams shall be returned again to them after being so used, as unpolluted as before it was used.
N.J.S. § 48:14-12