A. Location: The location of this area is based on the Special Flood Hazard Area boundary as delineated on the Scott County flood insurance rate maps dated April 11, 2024 and June 9, 2014 as revised and provided by the Federal Emergency Management Agency. The requirements of this section shall take precedence over any conflicting requirement of the city.
B. Uses Allowed: Permitted, special, temporary and accessory uses as set forth and regulated in the Bettendorf zoning ordinance are permitted in this area.
C. Site And Structure Requirements:
1. All development and structures shall conform to the requirements of the Bettendorf building code and to the requirements of the district in which the development is located in the Bettendorf zoning ordinance except for the additional requirements which are noted in this chapter.
2. All regulations in regard to area, width, yards, height, floor area ratio, and minimum size of dwelling shall conform to the zoning regulations of the city.
3. All proposed building sites will be reasonably safe from flooding. Earth fill or other materials may be used to raise the elevation of the land, provided it does not increase the flood level more than one foot (1') above the base flood elevation at any point. The amount of fill should not be greater than is necessary to achieve the purpose and requirements of this chapter, as demonstrated by a plan filed by the applicant showing the uses to which the filled land shall be put and the final dimensions of the proposed fill or other materials. Fill or other materials shall be protected against erosion by riprap, vegetative cover, or bulkheading.
4. All development must be consistent with the need to minimize flood damage and meet the following applicable performance standards. Where base flood elevations have not been provided in the Flood Insurance Study, the Iowa Department of Natural Resources shall be contacted to determine (i) whether the land involved is either wholly or partly within the floodway or floodway fringe and (ii) the base flood elevation. Until a regulatory floodway is designated, no development may increase the Base Flood Elevation more than one foot (1'). The applicant will be responsible for providing the Department of Natural Resources with sufficient technical information to make such determination.
D. Outside Storage:
1. The outside storage or processing of materials, machinery, or equipment that in the time of flooding are buoyant, flammable, explosive, pollutant or could be injurious to human, animal or plant life, may be permitted, if placed on a fill above the level of inundation for a base flood, or if adequately protected by a dike revetment, levee or similar structure. Storage of other material or equipment may be allowed without flood protection if firmly anchored to prevent flotation or if easily moved.
2. Due to the relative slow rise of the Mississippi River compared to its tributaries, the storage restrictions of this chapter will not be required if located exclusively in the Mississippi floodplain area and if the landowner or tenant can provide assurances in writing to the satisfaction of the building administrator that the aforementioned storage can be removed within a forty eight (48) hour period.
E. Anchoring Requirements: All new and substantially improved structures shall be: 1) designed and adequately anchored to prevent flotation, collapse or lateral movement of the structure; 2) constructed with materials and utility equipment resistant to flood damage; and 3) constructed by methods and practices that minimize flood damage.
F. Residential Elevation Requirements: All new or substantially improved residential structures shall have the lowest floor, including basement, elevated a minimum of two feet (2') above the base flood elevation. All new residential structures located in areas that would become isolated due to flooding of surrounding ground shall be provided with a means of access that will be passable by wheeled vehicles during the base flood. However, this criterion shall not apply where the Administrator determines there is sufficient flood warning time for the protection of life and property. When estimating flood warning time, consideration shall be given to the criteria listed in 567-75.2(3), Iowa Administrative Code.
G. Nonresidential Elevation Requirements:
1. All new or substantially improved nonresidential buildings shall have the first floor (including basement) elevated a minimum of two feet (2') above the base flood elevation, or together with attendant utility and sanitary systems, be floodproofed to such a level.
2. When floodproofing is utilized, a professional engineer registered in the state of Iowa shall certify that the floodproofing methods used are adequate to withstand the flood depths, pressures, velocities, impact and uplift forces and other factors associated with the base flood; and that the structure, below the base flood elevation, is watertight with walls substantially impermeable to the passage of water.
3. A record of the certification indicating the specific elevation (in relation to North American Vertical Datum 1988) to which any structures are floodproofed shall be maintained by the administrator.
H. Foundation And Facilities: Fully enclosed areas below the "lowest floor" (not including basements) that are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or meet or exceed the following minimum criteria:
1. A minimum of two (2) openings located to permit automatic entry and exit of floodwaters and having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding shall be provided.
2. The bottom of all openings shall be no higher than one foot above grade.
3. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
4. New and substantially improved structures shall be constructed with electric meter, electrical service panel box, hot water heater, heating, air conditioning, ventilation equipment (including ductwork), and other similar machinery and equipment elevated (or in the case on non-residential structures, optionally floodproofed to) a minimum of two feet (2') above the base flood elevation.
5. Such areas shall be used solely for parking of vehicles, building access, and low damage potential storage.
6. New and substantially improved structures must be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy.
7. New and substantially improved structures shall be constructed with plumbing, gas lines, water/gas meters and other similar service utilities either elevated (or in the case of non-residential structures, optionally floodproofed to) a minimum of two feet (2') above the base flood elevation or designed to be watertight and withstand inundation to such a level.
I. Factory-built homes:
1. All new and substantially improved factory-built homes including those placed in existing factory-built home parks or subdivisions shall be anchored to resist flotation, collapse or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. Anchorage systems may include, but are not limited to, use of over-the-top or frame ties to ground anchors as required by the State Building Code.
2. All new and substantially improved factory-built homes including those placed in existing factory-built home parks or subdivisions shall be elevated on a permanent foundation such that the lowest floor of the structure is a minimum of two feet (2') above the base flood elevation.
J. Utility And Sanitary Systems:
1. All new and replacement sanitary sewers must be sealed to prevent undue infiltration. Such infiltration shall not exceed the rate of fifteen (15) gallons per day per one hundred feet (100') of four-inch (4") sewer pipe, or twenty-two (22) gallons per day per one hundred feet (100') of six-inch (6") sewer pipe, or thirty (30) gallons per day per one hundred feet (100') of eight-inch (8") sewer pipe.
2. On site waste disposal and water supply systems shall be located or designed to avoid impairment to the system or contamination from the system during flooding.
3. New or replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system. Water supply treatment facilities shall be provided with a level of protection equal to or greater than two feet (2') above the base flood elevation.
4. Wastewater treatment facilities (other than on-site systems) shall be provided with a level of flood protection equal to or greater than two feet (2') above the base flood elevation.
5. Utilities such as gas or electrical systems shall be located and constructed to minimize or eliminate flood damage to the system and the risk associated with such flood-damaged or impaired systems.
K. No development shall affect the capacity of conveyance of the channel of floodway of any tributary to the main stream, drainage ditch, or other drainage facility or system.
L. Floodplain Area Standards; Subdivision Requirements:
1. Subdivision proposals intended for residential use shall provide all lots with a means of access which will be passable by wheeled vehicles during a base flood.
2. All proposals for subdivisions, regardless of size or number of lots, shall include base flood elevation data for those areas located within the area of significant flood hazard.
3. Subdivision proposals shall be consistent with the need to minimize flood damages and shall have adequate drainage provided to reduce exposure to flood damage.
4. Development associated with subdivision proposals (including the installation of public utilities) shall meet the applicable performance standards of this chapter.
M. Outbuildings And Non-major Buildings: Detached garages, sheds, and similar accessory type structures that are incidental to a residential use are exempt from the base flood elevation requirements when the following criteria are satisfied:
1. The structure shall be designed to have low flood damage potential. Its size shall not exceed six hundred (600) square feet in size. Those portions of the structure located less than two feet (2') above the base flood elevation must be constructed of flood-resistant materials.
2. The structure shall be designed to have low flood damage potential purposes such as vehicle parking and limited storage. The structure shall not be used for human habitation.
3. The structure shall be constructed and placed on the building site so as to offer minimum resistance to the flow of floodwaters.
4. Structures shall be firmly anchored to prevent flotation, collapse, and lateral movement which may result in damage to other structures.
5. The structure's service facilities such as electrical and heating equipment shall be elevated or floodproofed to at least two feet (2') above the base flood elevation.
6. The structure's walls shall include openings that satisfy the provision of subsection H of this section.
N. Recreational Vehicles:
1. Recreational vehicles are exempt from the requirements of subsection I of this section regarding anchoring and elevation of factory-built homes when the following criteria are satisfied:
a. The recreational vehicle shall be located on the site for less than one hundred eighty (180) consecutive days; and
b. The recreational vehicle must be fully licensed and ready for highway use. A recreational vehicle is ready for highway use if it is on its wheels or jacking system and is attached to the site only by quick disconnect type utilities and security devices and has no permanently attached additions.
2. Recreational vehicles that are located on the site for more than one hundred eighty (180) consecutive days or are not ready for highway use must satisfy requirements of subsection I of this section regarding anchoring and elevation of factory-built homes.
O. Flood Control Structural Works: Flood control structural works such as levees, floodwalls, etc., shall provide, at a minimum, protection from a base flood with a minimum of three feet (3') of design freeboard and shall provide for adequate interior drainage. In addition, the Department of Natural Resources shall approve structural flood control works.
P. Watercourse Alterations: 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.
Q. Stream Crossings: Pipeline river or stream crossings shall be buried in the stream bed and banks or otherwise sufficiently protected to prevent rupture due to channel degradation and meandering or due to the action of flood flows.
R. Maximum Damage Potential Development: All new or substantially improved maximum damage potential development shall have the lowest floor (including basement) elevated a minimum of one (1) foot above the elevation of the five hundred (500) year flood or, together with attendant utility and sanitary systems, be floodproofed to such a level. When floodproofing is utilized, a professional engineer registered in the State of Iowa shall certify that the floodproofing methods used are adequate to withstand the flood depths, pressures, velocities, impact and uplift forces, and other factors associated with the two tenths percent (0.2%) annual chance flood and that the structure, below the two tenths percent (0.2%) annual chance flood elevation, is watertight with walls substantially impermeable to the passage of water. A record of the certification indicating the specific elevation (in relation to North American Vertical Datum 1988) to which any structures are floodproofed shall be maintained by the Administrator. Where two tenths percent (0.2%) chance flood elevation data has not been provided in the Flood Insurance Study, the Iowa Department of Natural Resources shall be contacted to compute such data. The applicant will be responsible for providing the Department of Natural Resources with sufficient technical information to make such determinations. (Ord. 01-16, 1-5-2016; amd. Ord. 03-21, 2-16-2021; Ord. 07-24, 2-20-2024)
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