Ohio Revised Code Title XV. Conservation of Natural Resources § 1521.17

(A) The general assembly hereby finds and declares that the determination of the reasonableness of a use of water depends upon a consideration of the interests of the person making the use, of any person harmed by the use, and of society as a whole.

(B) In accordance with section 858 of the Restatement (Second) of Torts of the American law institute, all of the following factors shall be considered, without limitation, in determining whether a particular use of water is reasonable:

(C) In any determination of reasonable use of water under common law in which prior use is a factor, it shall be conclusive that one use is prior to another in the quantity claimed if the date of registration of one facility providing such use under section 1521.16 of the Revised Code is prior to that of another facility.

If a use of water in which prior use is a factor is by means of a facility having the capacity to withdraw one hundred thousand gallons or less of water per day and the facility is not registered under division (B) of that section, prior use shall be based on historic information and documentation provided by any person.