Mich. Comp. Laws § 121.1
As used in this act, "water supply and transmission system" means plants, works, instrumentalities and properties used or useful in connection with obtaining a water supply and the treatment thereof, and necessary transmission mains and appurtenances for the distribution of the water to the cities, villages and townships within the territorial limits of the authority. The cities, villages and townships shall continue to own, operate and maintain their own water distribution systems. It is the intent of this act to provide an equitable and reasonable method and means of financing and acquiring a central water supply and transmission system to supply potable water in sufficient quantities to local governmental units for distribution and sale to their own customers and users. The authority shall be limited to acquiring, owning and operating the central water supply and transmission system in the manner authorized by this act, either within or without the corporate limits of the authority.
MCL 121.1