Ohio Rev. Code § 6131.03
Boards of county commissioners in their respective counties, or in co-operation with any conservancy district which includes all or part of the lands of the county, or in co-operation with the proper authorities of the state or the proper authorities of the United States, may formulate, create, and construct a complete or co-ordinating system of water conservation and flood control, subject to the approval of the proper authority of the state, with full power to maintain and carry the same forward. Said boards, severally and jointly and in co-operation with the board of county commissioners of any other county, or with a conservancy district, or with the state, or with the United States, may provide their respective shares of necessary funds in accordance with law for the cost and expense of the formulation, creation, construction, and maintenance of such water conservation or flood control system, which costs and expense shall include the cost and expense of all preliminary surveys necessary to the construction and maintenance of such water conservation or flood control system.
R.C. § 6131.03