(A) Permitted uses. The permitted uses in the flood fringe district are all those uses of land or structures listed in Ch. 160 of this code of ordinances as permitted uses in the underlying zoning district(s). All permitted uses must meet the standards for Flood Fringe District’s permitted uses listed in division (B) below set forth below and the standards for all flood fringe uses listed in division (D) below.
(B) Standards for Flood Fringe District permitted uses.
(1) All structures in the Flood Fringe district, including accessory structures, must be elevated on fill so that the lowest floor (including the basement floor) is at or above the regulatory flood protection elevation. The finished fill elevation for structures shall be no lower than one foot below the regulatory flood protection elevation. The fill shall extend at such elevations at least 15 feet beyond the outside limits of the structure on the property.
(2) As an alternative to elevation on fill, owners of accessory structures in the flood fringe that constitute a minimal investment and that do not exceed 500 square feet in area may flood-proof the structures according to the following standards.
(a) Owners shall not intend, design, nor construct, accessory structures for human habitation.
(b) Accessory structures must be elevated on fill or structurally dry flood-proofed according to the FP-1 or FP-2 flood-proofing classifications in the state’s Building Code. As an alternative, an owner may flood-proof an accessory structure to the FP-3 or FP-4 flood-proofing classification in the state’s Building Code. For a detached garage, the owner must use the detached garage solely for parking of vehicles and limited storage. All flood-proofed accessory structures must meet the following additional standards.
1. Accessory structures must be adequately anchored to prevent flotation, collapse or lateral movement of the structure and shall be designed and constructed to equalize hydrostatic flood forces on exterior walls.
2. All mechanical and utility equipment in the accessory structure must be elevated to or above the regulatory flood protection elevation or properly flood-proofed.
3. To allow for the equalization of hydrostatic pressure, there must be a minimum of two “automatic” openings in the outside walls of the accessory structure having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding. There must be openings on at least two sides of the structure and the bottom of all openings must be no higher than one foot above the lowest adjacent grade to the structure. Using human intervention to open a garage door before flooding will not satisfy this requirement for automatic openings.
(3) The cumulative placement of fill on a parcel where at any one time is in excess of 1,000 cubic yards shall be allowed only as a conditional use, unless the fill is specifically intended to elevate a structure to meet the requirements of division (D) below.
(4) Property owners and users shall store or park any materials or equipment on fill to an elevation at or above the regulatory flood protection elevation.
(5) The provisions of division (D) below shall apply.
(C) Conditional uses. The city shall only allow structures that are not elevated on fill or flood-proofed according to divisions (D)(1) and (D)(2) below and or any use of land that does not meet the standards in divisions (D)(3) and (D)(4) below as a conditional use. An application for a conditional use permit shall be subject to the standards and criteria and evaluation procedures specified in divisions (D)(4) and (D)(5) below and in § 154.058 of this chapter, those standards and procedures set forth in Ch. 160 of the city code and elsewhere in the city code.
(D) Standards for flood fringe conditional uses.
(1) (a) An owner may use alternative elevation methods other than the use of fill 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 and the like or above-grade, enclosed areas such as crawl spaces or tuck under garages. The city shall consider the base or floor of an enclosed area 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 and constructed to internally flood and is constructed with flood resistant materials; and
3. The owner uses it solely for parking of vehicles, building access or storage.
(b) The above-noted alternative elevation methods are subject to the following additional standards.
1. Design and certification. A licensed professional engineer or architect must certify that the structure’s design and as-built condition meets the general design standards of the state’s Building Code. Specifically, 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 and constructed to prevent flood water from entering or accumulating in these components during times of flooding.
2. Specific standards for above-grade, enclosed areas. Owners and contractors shall design and construct above-grade, fully enclosed areas such as crawl spaces or tuck under garages to internally flood with design and construction plans that stipulate:
a. 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 licensed professional engineer or architect certifies that a smaller net area would suffice. The owner or contractor may equip the automatic openings with screens, louvers, valves or other coverings or devices if such devices permit the automatic entry and exit of flood waters without any form of human intervention; and
b. The enclosed area will be designed and constructed of flood resistant materials in accordance with the standards of the FP-3 or FP-4 classifications in the state’s Building Code and that the owner or occupants shall only use such areas for building access, vehicle parking or storage.
(2) Basements, as defined by § 154.011 of this chapter, shall be subject to the following requirements.
(a) The city does not permit residential basement construction below the regulatory flood protection elevation.
(b) The city may permit non- residential basements below the regulatory flood protection elevation; provided, the basement is structurally dry flood-proofed according to the standards listed in division (D)(3) below.
(3) All areas of non-residential structures (including basements) that would be below the regulatory flood protection elevation shall be flood-proofed to meet the structurally dry flood-proofing classifications in the state’s Building Code. Structurally dry flood-proofing must meet the FP-1 or FP-2 flood-proofing classification in the state’s Building Code. This flood-proofing shall require making the structure water-tight 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. The city does not allow structures in the flood fringe that the owners have flood-proofed to the FP-3 or FP-4 classification in the state’s Building Code. The city does not allow residential structures in the flood fringe that the owners have dry-flood-proofed to the FP-1 or FP-2 flood-proofing classification in the state’s Building Code.
(4) When at any one time a property owner or contractor wants to locate more than 1,000 cubic yards of fill or other similar material on a parcel for activities such as on-site storage, landscaping, sand and gravel operations, landfills, roads, dredge spoil disposal or construction of flood control works, the owner or contractor shall submit an erosion/ sedimentation control plan to the city for approval. The plan must clearly specify methods that an owner or contractor shall use to stabilize the fill on site for a flood event at a minimum of the 100-year or regional flood event. A registered professional engineer must prepare the plan. The plan may incorporate alternative procedures for removal of the material from the floodplain if adequate flood warning time exists.
(5) (a) The city prohibits the storage or processing of materials that are, in time of flooding, flammable, explosive or potentially injurious to human, animal or plant life.
(b) The city may allow the storage of other materials or equipment if they would be readily removable from the area within the time available after a flood warning is given and according to a plan that the city has approved.
(6) The provisions of division (E) below also shall apply.
(E) Standards for all flood fringe uses.
(1) All new principal structures in the flood fringe district must have vehicular access at or above an elevation not more than two feet below the regulatory flood protection elevation. If the city approves a variance from this requirement, the city must specify limitations on the period of use or occupancy of the structure for times of flooding. In order to approve a variance from this requirement, the city must determine that adequate flood warning time and local flood emergency response procedures exist.
(2) Accessory commercial land uses, such as yards, railroad tracks, and parking lots (if allowed by the underlying city zoning designation) may be at elevations lower than the regulatory flood protection elevation. However, the city shall not approve a permit for such facilities for use by employees or by the general public in the absence of a flood warning system. Such a flood warning system shall provide adequate time for evacuation if the area would be inundated to a depth and velocity such that when multiplying the depth (in feet) times velocity (in feet per second) the product number exceeds four upon occurrence of the regional flood.
(3) Owners and operators of manufacturing and industrial uses shall take measures to minimize the interference of normal plant operations from flooding, especially those sites along streams or creeks that have protracted flood durations. Certain accessory land uses such as yards and parking lots may be at lower elevations subject to requirements set out in division (E)(1) above. In considering development or permit applications for manufacturing or industrial uses, the city shall give due consideration to the needs of an industry whose business requires that it be located in floodplain areas.
(4) Contractors shall properly compact fill and properly protect the slopes by using riprap, vegetative cover or other acceptable methods. The Federal Emergency Management Agency (FEMA) has established criteria for removing the special flood hazard area designation for structures properly elevated on fill above the 100-year flood elevation. FEMA’s requirements incorporate specific fill compaction and side slope protection standards for multi-structure or multi-lot developments. The owner or contractor should investigate these standards before starting the site preparation if requesting a change of special flood hazard area designation.
(5) Floodplain developments shall not adversely affect the hydraulic capacity of the channel and adjoining floodplain of any tributary watercourse or drainage system where the city has not specified a floodway or other encroachment limit on the Official Zoning Map.
(6) Section 154.043(C) of this chapter lists the standards for the placement and use of recreational vehicles in the Flood Fringe District.
(7) (a) Owners and contractors shall securely anchor all manufactured homes to an adequately anchored foundation system that resists flotation, collapse and lateral movement.
(b) Methods of anchoring may include, but are not to be limited to, use of over-the-top or frame ties to ground anchors.
(c) This requirement is in addition to applicable state or local anchoring requirements for resisting wind forces.
(Prior Code, § 1301.05)