Ohio Rev. Code Ann. § 307.772

For the purposes of facilitating any project set forth in section 307.77 of the Revised Code and safeguarding the respective interests of the contributing counties, the respective boards of county commissioners may enter into such agreements with any public authority empowered to act with respect to any public improvement set forth in division (B)(1) and (2) of section 307.77 of the Revised Code under any act of congress or of the general assembly of this state, or the legislative authority of any other state, and also with counties and other subdivisions set forth in division (A) of section 307.77 of the Revised Code, as are necessary, with a view to effective co-operative action and providing for contributions in such proportion to benefits as may be agreed upon or found practicable.