Ohio Rev. Code § 5559.02: Grading, draining, and paving of platted lands outside of municipal corporations.

The board of county commissioners may, as provided in sections 5559.03 to 5559.16, inclusive, of the Revised Code, improve by grading, draining, paving, constructing storm sewers, sidewalks, curbs, and gutters, any road, street, alley, or portion thereof lying within or bounded on both sides by any platted lands, and situated outside a municipal corporation.