(A) Residential construction. New construction and substantial improvement of any residential structure shall have the lowest floor (including basement), elevated to a minimum of one foot above the base flood elevation. A registered professional engineer, architect or land surveyor shall submit a certification to the Floodplain Administrator that the standard of this section as proposed in § 152.057 is satisfied.
(B) Nonresidential construction. New construction and substantial improvements of any commercial, industrial or other nonresidential structure shall either have the lowest floor (including basement) elevated to a minimum of one foot above the base flood elevation or together with attendant utility and sanitary facilities, be designed so that below the base flood level the structure is water-tight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy. A registered professional engineer or architect shall develop and/or review structural design, specifications and plans for the construction, and shall certify that the design and methods of construction are in accordance with accepted standards of practice as outlined in this division (B). A record of such certification which includes the specific elevation (in relation to mean sea level) to which such structures are floodproofed shall be maintained by the Floodplain Administrator.
(C) Enclosures. New construction and substantial improvements, with fully enclosed areas below the lowest floor that are usable solely for parking of vehicles, building access or storage in an area other than a basement and which 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 architect or meet or exceed the following minimum criteria:
(1) A minimum of two openings on separate walls having a total net area of not less than one 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; and
(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.
(D) Manufactured homes.
(1) Require that all manufactured homes to be placed within Zone A on a community’s FHBM or FIRM shall be installed using methods and practices which minimize flood damage. For the purposes of this requirement, manufactured homes must be elevated and 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. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.
(2) Require that manufactured homes that are placed or substantially improved within Zones A1-30, AH and AE on the community’s FIRM on sites:
(a) Outside of a manufactured home park or subdivision;
(b) In a new manufactured home park or subdivision; and
(c) In an expansion to an existing manufactured home park or subdivision; or
(d) In an existing manufactured home park or subdivision on which a manufactured home has incurred “substantial damage” as a result of a flood, be elevated on a permanent foundation such bottom of the I-beam of the manufactured home is elevated at least one foot above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces. The home shall be installed by a licensed installer according to state law and compliance herewith shall be certified in writing to the Floodplain Administrator by said installer prior to habitation of the manufactured home.
(3) Require that manufactured homes be placed or substantially improved on sites in an existing manufactured home park or subdivision with Zones A1-30, AH and AE on the community’s FIRM that are not subject to the provisions of this section be elevated on a permanent foundation such that the bottom of the I-beam of the manufactured home is elevated at least 36 inches in height above the grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.
(E) Recreational vehicles. Require that recreational vehicles placed on sites within Zones A, A1-30, AH and AE on the county FIRM either:
(1) Be on the site for fewer than 180 consecutive days;
(2) Be fully licensed and ready for highway use; or
(3) Meet the permit requirements of § 152.057, and the elevation and anchoring requirements for manufactured homes in division (D) of this section. A recreational vehicle is ready for highway use if it is on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices and has no permanently attached additions.
(F) Accessory structure. Accessory structures to be placed on sites within Zones A and AE on the county FIRM shall comply with the following:
(1) The structure shall be used only for parking and limited storage;
(2) The structure shall not be used for human habitation. Prohibited activities or uses include, but are not limited to, working, sleeping, living, cooking or restroom use;
(3) The structure shall be unfinished on the interior;
(4) Structures shall be small in size, not exceed 600 square feet in size;
(5) Service facilities such as electrical and heating equipment must be elevated to or above the BFE plus one foot freeboard;
(6) The structure shall be constructed and placed on the building site so as to offer the minimum resistance to the flow of floodwaters;
(7) The structure shall be considered low in value, designed to have low flood damage potential and constructed with flood resistance materials;
(8) The structure shall be firmly anchored to prevent flotation, collapse and lateral movement;
(9) Floodway requirements must be met in the construction of the structure;
(10) Openings to relieve hydrostatic pressure during a flood shall be provided below the BFE; and be placed on opposing walls with the net area of not less than one square inch for every square foot of the size of the footprint of the structure (flood vents);
(11) The openings (flood vents) shall be located no higher than one foot above grade; and
(12) The openings may be equipped with screens, louvers, valves or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
(G) Parking.
(1) Parking is permitted within an area of special flood hazard only if the parking is transient in nature and incidental to a nonresidential use on the same property, provided that the area in which parking occurs may not represent more than 50% of the total parking area for that nonresidential or residential use on that property.
(2) Other parking, including long term parking, storage of vehicles, or parking related to a residential use is not permitted within an area of special flood hazard.
(H) Open storage.
(1) Open storage is permitted within an area of special flood hazard only when it is necessary due to the location of existing infrastructure that must necessarily be located in low-lying, flood-prone areas, such as wastewater treatment facilities, or that cannot be elevated for functional reasons, such as railroad tracks.
(2) Open storage is not permitted within the boundaries of a regulatory floodway.
(3) When open storage is permitted within an area of special flood hazard, all reasonable steps must be taken to ensure that the materials are reasonably safe from flooding, including requiring that materials be anchored in place where possible. Compensatory storage based on the maximum amount of material permitted to be stored below the elevation of the base flood is required. An emergency evacuation plan must be submitted and must detail reasonable steps to ensure that the stored material will not adversely impact other properties in the event of flooding.
(Ord. 381, passed 8-12-2021)