Whenever a canal or waterway of substantially definite route is authorized to be constructed by or under the authority, management, and control of the government of the United States, or of this state, either separately or jointly, or in co-operation with any state, or under the authority, management, and control of any state adjoining this state, to connect the great lakes or the ocean with the navigable waters of this state, or with the navigable waters of any adjoining state, by a route situated within or partly within and partly without the state, suitable for steamships, steamboats, barges, or other vessels, any county situated on the route thereof or connected therewith by navigable waters, railroad, or other highway of commerce, in such manner that the construction of such canal or waterway will be for the general public benefit of the community of such county, may give aid by the appropriation of money or the issue of bonds as provided by section 307.68 of the Revised Code.

Provided, that such canal or waterway shall be and remain exclusively a public enterprise, under public management, control, and operation, free from the private management, interest, or possession in any way of any individual company, corporation, association, or institution.

Provided, further, that of any surplus of tolls, rates, and charges accruing from the operation of such canal or waterway, or the sale of water or water power or from other income remaining after payment of the cost of operation, maintenance, and improvement, such county shall receive such proportionate part as its contribution bears to the total sum contributed for the construction of the canal or waterway.