How to Decide if a Permit
to Construct a Levee is Required
Unlike dams, a levee cannot be exempted solely because of its height. In fact, there are no exemption criteria for levees. A levee, may however, be placed into Class IV, as determined by the Chief, which would exempt the structure from a permit. However, the levee would remain under the jurisdiction of Ohio's Dam Safety Laws.
In order to determine if a permit is required, a preliminary design report must be submitted. If the levee is determined to be a Class I, II, or III, structure, a permit will be required and will follow the general guidelines as set forth for dams. Following approval of the preliminary design report, the final design report including the statutory filing fee and surety bond must be submitted.
The Ohio Administrative Code stipulates requirements for levees which are separate from those for dams.
Levees General Requirements
1. Future development of areas upstream, downstream, and adjacent to the levee shall be considered in the design.
2. The levee shall operate safely during all floods up to the design flood elevation.
3. Provisions for drainage of the area protected by the levee shall be incorporated into the structure. Measures shall be included to prevent flooding of this area by backflow through the drainage system.
4. The levee must be protected from or designed to prevent erosive velocities along the structure and its foundation.
5. Grass vegetation or other vegetation of similar properties are the only acceptable vegetative covers for earthen levee embankment surfaces. Vetch, trees and brush are not acceptable surface covers.
Levees Special Requirements
1. Hydraulic analyses shall be conducted to determine flood elevations for stream reaches affected by the construction of a levee and in accordance with rule 1501:21-13-10 of the Administrative Code. The analyses must provide flood depth and velocity data during the one-hundred-year, twenty-five-year, and five-year flood events, and for the top-of-levee flood event. For construction of new levees, the flood depths and velocities must be determined with and without the levee. The impact of increased flood depths and velocities on property and structures must be provided.
Design Flood for Levees
1. The design flood shall be established by the Chief in concert with the applicant's desired level of protection, but with the utmost interest in safeguarding life, health, and property. For Class I levees, the minimum design flood will be the 100-year flood or critical flood.
2. The magnitude of the design flood shall be determined from actual streamflow and flood frequency records or from synthetic hydrologic criteria based on current publications prepared by the Division of Water, the National Oceanographic and Atmospheric Administration (NOAA), the United States Army Corps of Engineers, the United States Geological Survey, or others specifically approved by the Chief.
Freeboard Requirements for Levees
Sufficient freeboard shall be provided to prevent overtopping of the levee due to passage of the design flood or due to severe frost damage, ice damage, stream obstruction, or wave action. The design freeboard shall not be reduced without the approval of the Chief.
1. For levees in Class I, the minimum elevations of the top of the levee shall be three feet higher than the maximum adjacent water surface elevation during passage of the design flood.
2. For levees in Class II and Class III, the minimum elevations of the top of the levee shall be two feet higher than the maximum adjacent water surface elevations during passage of the design flood.
3. Where special condition of severe frost damage, ice damage, stream obstruction, wave action, or impact of other structures may occur, the Chief may require elevations higher than required item 1 above.