Ord 2020-087/amending Chapter 39 of the SM Code regarding Flood Damage Prevention by providing for enhances flood damage prevention and mitigation standards

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velocities during the base flood are five feet per second or less protection shall be provided by covering them with vegetative cover; (d) Fill shall be composed of clean granular or earthen material. Sec. 39.49.2. Compensatory Storage. Fill within the special flood hazard area shall result in no net loss of natural floodplain storage, or increase in water surface elevations during the base flood. The volume of the loss of floodwater storage due to filling in the special flood hazard area shall be offset by providing an equal volume of flood storage by excavation or other compensatory measures at or adjacent to the development site. Sec. 39.050. Preservation of natural features. No wetlands or other significant natural features shall be reclaimed within a water quality zone or buffer zone established under articles 1, 2 or 3 of chapter 5 of the city's land development code authorized under a mitigation plan prepared in accordance with this article, which demonstrates that reclamation or alteration of the floodplain will improve the water quality of the runoff and/or stabilize an existing area of erosion and will continue the maintenance of flood and flow characteristics of the waterway, and which provides for protection of altered areas during and after alteration and development of adjacent land. Sec. 39.051. Floodplain easements. Appropriate drainage and flood maintenance easements shall be granted to the city prior to approval of a plat application on all floodplain land that remains following reclamation authorized under the approved qualified watershed protection plan. Sec. 39.052. Stream velocity. Alterations of the floodplain shall not create an erosive water velocity on- or off-site. The mean velocity of stream flow at the site after fill shall be no greater than the mean velocity of the stream flow under existing conditions. No alteration to the floodplain will be permitted which would increase velocities of flood waters to the extent that significant erosion of floodplain soils will occur either on the subject property or on other properties whether adjacent, upstream or downstream. Mean channel velocities that exceed six f.p.s. are considered to be erosive. Sec. 39.053. Side slopes. (a) The following standards apply to slide slopes: (1) To insure maximum accessibility to the floodplain for maintenance and other purposes, and to lessen the probability of slope erosion during periods of high