1. Statement of Intent. It is the intent of the FW Floodway District that the identified area is designed to carry floodwaters and is to be protected from developmental encroachment, which would increase flood levels or cause unnecessary damage to personal property or pose unnecessary threats to personal safety.
A. Structures that impede the free flow of floodwaters will not be allowed.
2. Permitted Development. All development within the FW Floodway District shall meet applicable performance standards of the FW Floodway District and any other ordinance or underlying zoning district as defined in the Story County Land Development Regulations.
A. No development shall cause any increase in the one percent annual chance or greater 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 development within the FW 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 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. Utilities, if permitted, shall meet the applicable development 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 be designed for low flood damage potential and shall not be for human habitation.
F. Storage of equipment or materials that are buoyant, flammable, explosive, or injurious to human, animal, or plant life is prohibited.
(1) Storage of other material may be allowed if readily removable from the FW Floodway District within an approved timeframe available after flood warning subject to submission and approval by the Floodplain Manager of an evacuation plan.
G. Watercourse alterations or relocations (channel changes and modifications) must be designed to maintain the flood carrying capacity within the altered or relocated portion. Such alterations or relocations must be approved by the Iowa Department of Natural Resources prior to approval of a permit by Story County.
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. Only trenchless construction methods shall be permitted for pipeline installations. An undisturbed stream buffer shall be maintained where trenchless methods are also required. The buffer shall be 50 feet or the channel width, measured as the average width between the top of the opposing banks, whichever is greater. The buffer shall be the required width on either side of the stream measured from the stream edge. The buffer may be reduced to the width of the Special Flood Hazard Area in the case that the required buffer is larger than the Special Flood Hazard Area.
(Ord. 302 - Sep. 22 Supp.)