(A) Detention policy. It is recognized that most streams and drainage channels serving the town do not have sufficient capacity to receive and convey storm water runoff resulting from continued urbanization. Accordingly, except for situations provided in § 53.045(C) and (D), the storage and controlled release of excess storm water runoff shall be required for all developments and redevelopments (as defined in § 53.075) located within Edinburgh.
(B) Floodplain storage policy.
(1) Floodplains exist adjacent to all natural and manmade streams, regardless of contributing drainage area or whether they have been previously identified or mapped. Due to potential impacts of floodplain loss of peak flows in streams and on the environment, disturbance to floodplains should be avoided. When the avoidance of floodplain disturbance is not practical, the natural functions of floodplain should be preserved to the extent possible.
(2) Compensatory excavation equivalent to the floodplain storage lost (no net loss) shall be required for all activities within floodplain of streams located in the town where the drainage area of the stream upstream of the project is equal or larger than one square mile. This requirement shall be above and beyond the minimum requirements provided in the applicable flood hazard areas ordinance currently in effect in the town. The DSM and/or the permitting officer may alter the compensation ratio, based on extenuating circumstances, for a specific project.
(3) Compensatory storage is the replacement of the existing floodplain storage lost due to fill. Compensatory storage is required when a portion of the floodplain is filled or because of a project a change in the channel hydraulics occurs that reduces the existing available floodplain storage. The compensatory storage should be located adjacent or opposite the placement of the fill and maintain an unimpeded connection to an adjoining floodplain area.
(Ord. 2023-22, passed 12-28-23)