The following standards apply within the regulatory floodplain or, for sites draining more than 640 acres, the limits of the delineated floodplain as accepted by the Administrator.
(A) Hydraulically equivalent compensatory storage volume will be required for development in a riverine regulatory floodplain and shall be at least equal to the regulatory floodplain flood storage volume displaced. The storage volume displaced below the existing 10-year frequency flood elevation must be replaced below the proposed 10-year frequency flood elevation. The storage volume displaced above the 10-year existing frequency flood elevation must be replaced above the proposed 10-year frequency flood elevation. Additional storage of not less than 50% of the net volume displaced shall be provided based upon the total volume filled below the BFE. The additional 50% need not be hydraulically equivalent. The volume of storage lost shall be calculated based on the existing BFE and the volume of compensatory storage shall be calculated based upon the final with project BFE.
(B) Compensatory storage volume for development in a non-riverine regulatory floodplain area that is also adjacent to a lake shall be equal to the storage volume displaced. Additional storage of not less than 50% of the net volume displaced shall be provided. The volume of storage lost shall be calculated based on the existing BFE and the volume of compensatory shall be calculated based upon the final with project BFE.
(C) Compensatory storage volume requirements for development in a non-riverine regulatory floodplain that is not adjacent to a lake shall be replaced in accordance with the requirements for the loss of depressional storage in § 160.019 of this chapter.
(D) The hydraulically equivalent compensatory storage areas shall be designed to drain freely and openly to the channel and shall be located adjacent to the development. This standard does not apply to non-riverine regulatory floodplain.
(E) A recorded covenant running with the land is required to maintain the compensatory storage volume in areas modified to provide compensatory storage volume.
(Ord. 06-0383, passed 3-15-06)