As of 2015, the State of Ohio, through ODNR, owns and maintains 177 dams statewide, which include 56 Class I high-hazard potential dams. These are classified according to the potential impact a dam failure (unplanned breach) would have on upstream and/or downstream areas or at locations remote from the dam. Also among the state-owned total are 36 Class II, 26 Class III, 17 Class IV, and 42 exempt (from regulation) dams. Ohio law defines a Class I high-hazard potential dam as those structures that impound a total storage volume greater than 5,000 acre-feet or a height of greater than 60 feet or where sudden failure of a Class I dam would result in probable loss of human life and structural collapse of at least one residence or one commercial or industrial business. The hazard potential classification does not reflect in any way on the current condition of the dam (e.g. safety, structural integrity, or flood routing capacity).
ODNR regulates more than 1,500 publicly and privately-owned dams through the Division of Water Resource's Dam Safety Program. Most of these dams are either privately-owned or owned by local governments and have a wide variety of uses including water supplies and recreation. There are about 30 federally-owned dams in Ohio that are regulated through the U.S. Army Corps of Engineers (USACE). The goal of ODNR's Dam Safety Program is to enhance public safety by ensuring that dams do not present unacceptable risks to people, property and the environment. One step in meeting this goal is to perform periodic dam safety inspections. These certified inspections may result in program officials directing dam owners, including the State of Ohio, to implement needed repairs or other risk-reduction measures and prepare for dam emergencies.
More information about Ohio's dams and the Ohio Dam Safety Program can be reviewed online at:
Information on the Dam Risk Reduction Program and current dam projects can be found online at: