Ohio Rev. Code § 743.18
A municipal corporation which has water works or electric works may contract with any other municipal corporation to supply it or its inhabitants with water or electricity upon such terms as are agreed upon by their respective legislative authorities. A municipal corporation which has a water works may dispose of surplus water, for manufacturing or other purposes, by lease or otherwise, upon such terms as are agreed upon by the director of public service of a city or the board of trustees of public affairs of a village and approved by the legislative authority thereof. Moneys received for such surplus water in either case shall be applied to the payment of the principal and interest of the bonds issued for the construction of such water works, or for other expenses incident to the maintenance thereof, but no lease shall be made for a longer term than twenty years.
The amount to be paid for such water supply shall be raised by the municipal corporation purchasing it, in the manner provided for the payment of the expense of conducting and managing water works constructed wholly by a municipal corporation. The amount so received by the municipal corporation furnishing such supply shall be applied to the payment of the interest on the sum borrowed for the construction of such water works, or to defray the expense of its management, as the director of public service or board of trustees directs.
R.C. §743.18