Chapter 25.86 FLOOD PLAIN MANAGEMENT AND OVERLAY ZONES


Section 25.86.110 Floodway Overlay District (FW):

    1. Permitted Uses. The following uses shall be permitted within the Floodway District to the extent they are not prohibited by any other ordinance or by the underlying zoning district and provided they do not include placement of structures, factory-built homes, fill or other obstruction, the storage of materials or equipment, excavation, or alteration of a watercourse.
        a. Agricultural uses such as general farming, pasture, grazing, outdoor plant nurseries, horticulture, viticulture, truck farming, forestry, sod farming, and wild crop harvesting.
        b. Industrial-commercial uses such as loading areas, parking areas, airport landing strips.
        c. Private and public recreational uses such as golf courses, tennis courts, driving ranges, archery ranges, picnic grounds, boat launching ramps, swimming areas, parks, wildlife and nature preserves, game farms, fish hatcheries, shooting preserves, target ranges, trap and skeet ranges, hunting and fishing areas, hiking trails, biking trails, and horseback riding trails.
        d. Residential uses such as lawns, gardens, parking areas and play areas.
        e. Such other open-space uses similar in nature to the above uses.
    2. Conditional Uses. The following uses which involve structures (temporary or permanent), fill, storage of materials or equipment may be permitted only upon issuance of a Conditional Use Permit by the Board of Adjustment as provided for in Section 25.86.150-3. Such uses must also meet the applicable provisions of the Floodway District Performance Standards.
        a. Uses or structures accessory to open-space uses.
        b. Circuses, carnivals, and similar transient amusement enterprises.
        c. Drive-in theaters, new and used car lots, roadside stands, signs, and billboards.
        d. Extraction of sands, gravel, and other materials.
        e. Marinas, boat rentals, docks, piers, wharves.
        f. Utility transmission lines, underground pipelines.
        g. Other uses similar in nature to uses described in Section 25.86.110-1 or 2 which are consistent with the provisions of Section 25.86.110-3 and the general spirit and purpose of this chapter.
    3. Performance Standards. All Floodway District uses allowed as a permitted or conditional use shall meet the following standards:
        a. No use shall be permitted in the Floodway District that would result in any increase in the 100-year flood level. Consideration of the effects of any development on flood levels shall be based upon the assumption that an equal degree of development would be allowed for similarly situated lands.
        b.  All uses within the Floodway District shall:
            (1) Be consistent with the need to minimize flood damage.
            (2) Use construction methods and practices that will minimize flood damage.
            (3) Use construction materials and utility equipment that are resistant to flood damage.
        c. No use shall affect the capacity or conveyance of the channel or floodway or any tributary to the main stream, drainage ditch, or any other drainage facility or system.
        d. Structures, buildings and sanitary and utility systems, if permitted, shall meet the applicable performance standards of the Floodway Fringe District and shall be constructed or aligned to present the minimum possible resistance to flood flows.
        e. Buildings, if permitted, shall have a low flood damage potential and shall not be for human habitation.
        f. Storage of materials or equipment that are buoyant, flammable, explosive or injurious to human, animal or plant life is prohibited. Storage of other material may be allowed if readily removable from the Floodway District within the time available after flood warning.
        g. Watercourse alterations or relocations (channel changes and modifications) must be designed to maintain the flood carrying capacity within the altered or relocated portion. In addition, such alterations or relocations must be approved by the Iowa Department of Natural Resources.
        h. Any fill allowed in the floodway must be shown to have some beneficial purpose and shall be limited to the minimum amount necessary.
        i. Pipeline river or stream crossings shall be buried in the streambed and banks or otherwise sufficiently protected to prevent rupture due to channel degradation and meandering or due to the action of the flood flows.  (Ord. 89/T-7348)