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2 Ownership FIA will not consider privately owned, operated or maintained levee systems ~nless local ordinance or state statute mandates operation and maintenance. Levees for which the community, state, or Federal government has responsibility for operation and maintenance will be considered by FIA provided that the criteria disc~ssed below are met. Design Requirements The Federal Insurance Administration has the responsibility under Public La~ 90-488 to identify the special flood hazard areas of the United States. The Special Flood Hazard Area has been defined as that area subject to a one percent or greater annual chance of flooding. In order for FIA to remove the special flood hazard designation from an area "protected'" by levees, we must be assured that the area involved does not fall within this definition. The degree of protection afforded by a levee system is uncertain because of both the uncertainty involved in establishing the one percent chance flood elevations and the uncertainty involved in the structural stability of the levee itself. Common engineering practice in the construction of flood protection works, such as dams and levees is the inclusion of a freeboard allowance above the computed water surface levels, to allow for all of the uncertainties in analysis, design and construction which cannot be fully or readily considered in an analytical fashion. In the case of the National Flood Insurance Program, freeboard allowances must be a major factor in establishing a levee's probability of providing protection against the true one percent annual chance flood. FIA must be reasonably c~rtain of this level of protection before the flood plain management, insurance purchase, and lender notification requirements under the Program can be removed from the leveed area. FIA will require a minimum levee freeboard of three feet, with an additional foot within 100 feet either side of structures within the levee or where ever the flow is constricted, such as at bridges. An additional half-foot above this minimum is also required at the upstream end, tapering to the minimum at the downstream end of the levee. This standard has been generally utilized by the Corps for levees protecting populated areas, and is based on long term experience with the success and failure of levee systems. The above criteria will be utilized to eval~ate levee systems in all ongoing and future analyses of flood hazards conducted by FlA. This includes initial identifications, studies, restudies, map revisions, LOMA's, etc. At the present time, no effort should be undertaken to revise maps for the sole purpose of implementing this policy. However, this policy shall be applied for all maps issued by FIA from the date of this memo and for which the six-month compliance