A. Permitted Uses: Permitted uses are those uses of land or structures allowed in the underlying zoning district(s) that comply with the standards in subsection B of this section. If no pre-existing, underlying zoning district exists, then any residential or nonresidential structure, or use of a structure of land, is a permitted use, provided it does not constitute a public nuisance.
B. Standards For Flood Fringe Permitted Uses:
1. All structures, including accessory structures, must be elevated on fill so that the lowest floor, as defined, is at or above the regulatory flood protection elevation. The finished fill elevation for structures must be no lower that one foot (1') below the regulatory flood protection elevation and the fill must extend at the same elevation at least fifteen feet (15') beyond the outside limits of the structure.
2. As an alternative to the fill, requirements of subsection B1 of this section, structures accessory to the uses identified in subsection A of this section may be permitted to be internally/wet floodproofed to the FP3 or FP4 floodproofing classifications in the International Building Code, provided that:
a. The accessory structure constitutes a minimal investment, does not exceed five hundred seventy six (576) square feet in size, and is only used for parking and storage.
b. To allow for the equalization of hydrostatic pressure, there must be a minimum of two (2) "automatic" openings in the outside walls of the structure, with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding; and
c. There must be openings on at least two (2) sides of the structure and the bottom of all openings must be no higher than one foot (1') above the lowest adjacent grade to the structure. Using human intervention to open a garage door prior to flooding will not satisfy this requirement for automatic openings.
3. The cumulative placement of fill or similar material on a parcel must not exceed one thousand (1,000) cubic yards unless the fill is specifically intended to elevate a structure in accordance with subsection A of this section or if allowed as a conditional use under subsection C of this section.
4. The storage of any materials or equipment must be elevated on fill to the regulatory flood protection elevation.
5. All service utilities, including ductwork, must be elevated or watertight to prevent infiltration of floodwaters.
6. All fill must be properly compacted and the slopes must be properly protected by the use of riprap, vegetative cover or other acceptable method.
7. All new principal structures must have vehicular access at or above an elevation not more than two feet (2') below the regulatory flood protection elevation or must have a warning/emergency evacuation plan acceptable to the City Council.
8. Accessory uses such as yards, railroad tracks, and parking lots may be at an elevation lower than the regulatory flood protection elevation. However, any facilities used by employees or the general public must be designed with a flood warning system that provides adequate time for evacuation if the area is inundated to a depth and velocity such that the depth, in feet, multiplied by the velocity, in feet per second, would exceed a product of 4 upon occurrence of the regional, one percent (1%) chance, flood.
9. Manufactured homes and recreational vehicles must meet the standards of these regulations.
C. Conditional Uses: The following uses and activities may be allowed as conditional uses, if allowed in the underlying zoning district(s) or any applicable overlay district, following the procedures in section 11.04 of this chapter.
1. Storage of any material or equipment below the regulatory flood protection elevation.
2. The cumulative placement of more than one thousand (1,000) cubic yards of fill when the fill is not being used to elevate a structure in accordance with subsection B1 of this section.
3. The use of methods to elevate structures above the regulatory flood protection elevation, including stilts, pilings, parallel walls or above-grade, enclosed areas such as crawl spaces or tuck under garages, shall meet the standards in subsection D6 of this section.
D. Standards For Flood Fringe Conditional Uses:
1. The standards listed in subsections B4 through B9 of this section apply to all conditional uses.
2. Residential basements, as defined by these regulations, are not allowed below the regulatory flood protection elevation.
3. All areas of nonresidential structures, including basements, to be placed below the regulatory flood protection elevation must be structurally dry floodproofed, meeting the FP1 or FP2 floodproofing classification in the International Building Code, which requires making the structure watertight with the walls substantially impermeable to the passage of water and with structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy.
4. The placement of more than one thousand (1,000) cubic yards to fill or other similar material on a parcel, other than for the purpose of elevating a structure to the regulatory flood protection elevation, must comply with an approved erosion/sedimentation control plan.
a. The plan must clearly specify methods to be used to stabilize the fill on site for a flood event at a minimum of the regional, one percent (1%) chance, flood event.
b. The plan must be prepared and certified by a registered professional engineer or other qualified individual acceptable to the City Council.
c. 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 below the regulatory flood protection elevation must comply with an approved emergency plan providing for removal of such materials within the time available after a flood warning.
6. 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. The base or floor of an enclosed area shall be considered above-grade and not a structure's basement or lowest floor if: a) the enclosed area is above-grade on at least one side of the structure; b) it is designed to internally flood and is constructed with flood resistant materials; and c) 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 as being in compliance with the general design standards of the International Building Code and specially, 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. Structure shall be subject to a nonconversion agreement with upon the issuance of any permit.
b. Fully 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) The minimum area of openings in the walls where internal flooding is to be used as a floodproofing technique. There shall be a minimum of two (2) openings on at least two (2) sides of the structure and the bottom of all openings shall be no higher than one foot (1') 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 exit 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 FP3 or FP4 classifications in the International Building Code and shall be used solely for building access, parking of vehicles or storage. (Ord. 10, 7th Series, eff. 7-2-2018)