A. Permitted Uses. Permitted uses shall be those permissible uses of land allowed in the underlying zoning district (permitted uses, conditional uses, and interim uses) established in Chapter 7A (Zoning Ordinance) of the City Code that comply with the underlying zoning district requirements and the “Standards for Flood Fringe District Permitted Uses” listed in Section 7F-450E.
B. Standards for Flood Fringe Permitted Uses.
1. All structures, accessory structures, and temporary construction uses and structures, including but not limited to fuel tanks, transportable construction offices, and portable toilets, must be elevated on fill so that the lowest floor including basement floor is at or above the regulatory flood protection elevation. The finished fill elevation for structures shall be not lower than one (1) foot below the regulatory flood protection elevation and the fill shall extend at such elevation at least fifteen (15) feet beyond the outside limits of the structure erected thereon.
2. As an alternative to elevation on fill, accessory structures that constitute a minimal investment and that do not exceed 500 square feet at its largest projection may be internally flood proofed in accordance with Section 7F-440D.5(c) of this Ordinance.
3. The cumulative placement of fill where at any one time in excess of one-thousand (1,000) cubic yards of fill is located on the parcel shall be allowable only as a conditional use, unless said fill is specifically intended to elevate a structure in accordance with this Ordinance.
4. The storage of any materials or equipment shall be elevated on fill to the regulatory flood protection elevation.
5. The provisions of Section 7F-450E. of this ordinance shall apply.
C. Conditional Uses. Conditional uses shall be those uses of land allowed in the underlying zoning district established in Chapter 7A (Zoning Ordinance) of the City Code that do not comply with the “Standards for Flood Fringe District Permitted Uses” listed in Section 7F-450B. All conditional uses shall comply with the “Standards for Flood Fringe District Conditional Uses” listed in Section 7F-450D. and the “Standards for all Flood Fringe Uses” listed in Section 7F-450E. Any structure that is not elevated on fill or flood proofed in accordance with Section 7F-450B. of This Ordinance shall only be allowable as a conditional use. All Flood Fringe conditional uses shall be subject to the procedures and standards contained in this Ordinance and Chapter 7A (Zoning Ordinance) of the City Code.
D. Standards for Flood Fringe Conditional Uses.
1. Alternative elevation methods other than the use of fill may be utilized to elevate a structure’s lowest floor above the regulatory flood protection elevation. These alternative methods may include the use of stilts, pilings, parallel walls, etc., or above-grade, enclosed areas such as crawl spaces or tuck under garages. The base or floor of an enclosed area shall be considered above-grade and not a structure’s basement or lowest floor if: 1) the enclosed area is above-grade on at least one side of the structure; 2) it is designed to internally flood and is constructed with flood resistant materials; and 3) it is used solely for parking of vehicles, building access or storage. The above-noted alternative elevation methods are subject to the following additional standards:
(a) Design and Certification – The structure’s design and as-built condition must be certified by a registered professional engineer or architect as being in compliance with the general design standards of the State Building Code and, specifically, that all electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities must be at or above the regulatory flood protection elevation or be designed to prevent flood water from entering or accumulating within these components during times of flooding.
(b) Specific Standards for Above-grade, Enclosed Areas – Above-grade, fully enclosed areas such as crawl spaces or tuck under garages must be designed to internally flood and the design plans must stipulate:
(1) A minimum area of “Automatic” openings in the walls where internal flooding is to be used as a flood proofing technique. There shall be a minimum of two openings on at least two sides of the structure and the bottom of all openings shall be no higher than one-foot above grade. The automatic openings shall have a minimum net area of not less than one square inch for every square foot of enclosed area subject to flooding unless a registered professional engineer or architect certifies that a smaller net area would suffice. The automatic openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exist of flood waters without any form of human intervention; and
(2) That the enclosed area will be designed of flood resistant materials in accordance with the FP-3 or FP-4 classifications in the State Building Code and shall be used solely for building access, parking of vehicles or storage.
2. Basements, as defined in this Ordinance, shall be subject to the following:
(a) Residential basement construction shall not be allowed below the regulatory flood protection elevation.
(b) Non-residential basements may be allowed below the regulatory flood protection elevation provided in the basement is structurally dry flood proofed in accordance with this Ordinance.
3. All areas of non residential structures including basements to be placed below the regulatory flood protection elevation shall be flood proofed in accordance with the structurally dry flood proofing classifications in the State Building Code. Structurally dry flood proofing must meet the FP-1 or FP-2 flood proofing classification in the State Building Code and this shall require making the structure watertight with the walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. Structures flood proofed to the FP-3 or FP-4 classification shall not be permitted.
4. When at any one time more than 1,000 cubic yards of fill or other similar material is located on a parcel for such activities as on-site storage, landscaping, sand and gravel operations, roads, or construction of flood control works, an erosion/sedimentation control plan must be submitted unless the community is enforcing a state approved shoreland management ordinance. In the absence of a state approved shoreland ordinance, the plan must clearly specify methods to be used to stabilize the fill on site for a flood event at a minimum of the 100-year or regional flood event. The plan must be prepared and certified by a registered professional engineer or other qualified individual acceptable to the City Council. The plan may incorporate alternative procedures for removal of the material from the floodplain if adequate flood warning time exists.
5. Storage of Materials and Equipment:
(a) The storage or processing of materials that are, in time of flooding, flammable, explosive, or potentially injurious to human, animal, or plant life is prohibited.
(b) Storage of other materials or equipment, subject to the provisions of the underlying zoning district established in Chapter 7A (Zoning Ordinance) of the City Code, may be allowed if readily removable from the area within the time available after a flood warning and in accordance with a plan approved by the City Council.
6. The provisions of subsection E. Below shall also apply.
E. Standards for All Flood Fringe Uses.
1. All new principal structures must have vehicular access at or above an elevation not more than two (2) feet below the regulatory flood protection elevation. If a variance to this requirement is granted, the Board of Adjustments and Appeals must specify limitations on the period of use or occupancy of the structure for times of flooding and only after determining that adequate flood warning time and local flood emergency response procedures exist.
2. Commercial Uses – accessory land uses, such as yards, railroad tracks, and parking lots may be at elevations lower that the regulatory flood protection elevation. However, a permit for such facilities to be used by the employees or the general public shall not be granted in the absence of a flood warning system that provides adequate time for evacuation if the area would be inundated to a depth and velocity such that when multiplying the depth (in feet) times the velocity (in feet per second) the product number exceeds four (4) upon occurrence of the regional flood.
3. Manufacturing and Industrial Uses – measures shall be taken to minimize interference with normal plan operations especially along streams having protracted flood durations. Certain accessory land uses such as yards and parking lots maybe at lower elevations subject to requirements set out in this Section. In considering permit applications, due consideration shall be given to needs of an industry whose business requires that it be located in floodplain areas.
4. Fill shall be property compacted and the slopes shall be properly protected by the use of riprap, vegetative cover or other acceptable method. The Federal Emergency Management Agency (FEMA) has established criteria for removing the special flood hazard area designation for certain structures properly elevated on fill above the 100-year flood elevations – FEMA’s requirements incorporate specific fill compaction and side slope protection standards for multi-structure or multi-lot developments. These standards should be investigated prior to the initiation of site preparation if a change of special flood hazard area designation will be requested.
5. Floodplain developments shall not adversely affect the hydraulic capacity of the channel and adjoining floodplain of any tributary watercourse or drainage system where a floodway or other encroachment limit has not been specified in the Official Zoning Map.
6. Standards for recreational vehicles are contained in Article VII.
7. Temporary construction uses and structures, including but not limited to fuel tanks, transportable construction offices, and portable toilets, shall not be located in the FF District unless the standards in Section 7F-450B.1. re met.
F. Interim Uses. Interim uses shall be those interim uses of land allowed in the underlying zoning district established in Chapter 7A (Zoning Ordinance) of the City Code, and as allowed in this Section.
H. Dimensional Standards. Dimensional standards in the FF District shall be consistent with those applicable in the underlying zoning district established in Chapter 7A (Zoning Ordinance) of the City Code, except as modified by this Ordinance.
I. Other Applicable Provisions. All other provisions of this Ordinance and Chapter 7A (Zoning Ordinance) shall apply to the FF District, including but not limited to performance standards, general provisions, administrative provisions, and enforcement.