17.40.060 Floodway (overlay) district (FW).
(1) Permitted Uses.
(a) All development within the floodway district shall be permitted to the extent that they are not prohibited by any other ordinance (or underlying zoning district) and provided they meet applicable performance standards of the floodway district. The following with the issuance of a flood development permit by the city zoning administrator are permitted without a variance or approval by the Department of Natural Resources; provided they do not include placement or construction of vertical structures such as habitable structures, factory-built homes, fill, the storage of materials or equipment, excavation, or alteration of a watercourse or other obstruction:
(i) Agricultural uses such as general farming, pasture, grazing, outdoor plant nurseries, horticulture, viticulture, truck farming, forestry, sod farming, and wild crop harvesting.
(ii) Signs, billboards, utility transmission lines and pipelines.
(iii) Private and public recreational uses such as driving ranges, archery ranges, picnic grounds, boat launching ramps, swimming areas, parks, wildlife and nature preserves, game farms, shooting preserves, target ranges, trap and skeet ranges, hunting and fishing areas, hiking and horseback riding trails; provided, that they meet the applicable floodway overlay district performance standards.
(iv) Residential uses such as lawns, gardens and play areas.
(v) Grading provided there is no change of surface topography of more than one foot and no fill is introduced into the floodway.
(vi) Such other open space uses similar in nature to the above uses.
Any use not listed above is considered a special use and requires a no-rise certificate from a professional engineer, a review of Iowa DNR and a city zoning variance. Additionally, the Iowa DNR should be contacted to determine the exact location of the floodway boundary.
(2) Performance Standards. All floodway district uses allowed as a permitted use shall meet the following standards:
(a) No development shall be permitted in the floodway district that would result in any increase in the base flood elevation. Consideration of the effects of any development on flood levels shall be based upon the assumption that an equal degree of development would be allowable for similarly situated lands.
(b) All development within the floodway district shall:
(i) Be consistent with the need to minimize flood damage.
(ii) Use construction methods and practices that will minimize flood damage.
(iii) Use construction materials and utility equipment that are resistant to flood damage.
(c) No development shall affect the capacity or conveyance of the channel or floodway of any tributary to the main stream, drainage ditch or any other drainage facility or system.
(d) Structures, buildings, recreational vehicles, 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) Structures, if permitted, shall have low flood damage potential and shall not be for human habitation.
(f) Storage of materials or equipment that is 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 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 flood flows. [Ord. 606, 2022.]