Ohio Rev. Code Ann. § 1521.28

The chief of the division of water resources shall use the data submitted under sections 1521.24 to 1521.27 of the Revised Code to establish the geographic area defined by the ten-foot contour line of the projected cone of depression for any approved application for the withdrawal of ground water. However, the chief may designate a different contour line based upon water resource availability, seasonal variations, other water users in the hydrologic study area, or other ground water data available.