In all special flood hazard areas the following standards are required:
(A) Anchoring.
(1) All new construction and substantial improvements shall be anchored to prevent flotation, collapse or lateral movement of the structure resulting from hydrodynamic loads and hydrostatic loads including the effects of buoyancy. A foundation design and certification by a registered professional engineer may be required to ensure the standards of this division.
(2) All manufactured homes shall meet the anchoring standards of § 152.049(B).
(B) Construction materials and methods.
(1) All new construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage.
(2) All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage.
(3) All new construction, substantial improvement and other proposed new development shall be constructed with electrical, heating, ventilation, plumbing and air conditioning equipment and other service facilities that are designed and/or located so as to prevent water from entering or accumulating within the components during conditions of flooding.
(4) Require within Zones AH or AO that adequate drainage paths around structures on slopes guide floodwaters around and away from proposed or existing structures.
(C) Elevation and flood-proofing.
(1) New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above the regulatory flood elevation. Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor and provided to the Floodplain Administrator.
(2) New construction and substantial improvement of any residential structure in Zone AO shall have the lowest floor, including basement, higher than the highest adjacent grade at least one foot higher than the depth number on the FIRM, or at least two feet if no depth number is specified. Upon the completion of the structure, the elevation of the lowest floor including basement shall be certified by a registered professional engineer or surveyor and provided to the Floodplain Administrator that the elevation of the structure meets this standard.
(3) Nonresidential construction and new and substantial improvement shall either be elevated in conformance with § 152.045(C)(1) or (2) or together with attendant utility and sanitary facilities:
(a) Be flood-proofed so that below the regulatory flood level the structure is watertight with walls substantially impermeable to the passage of water; nonresidential structures may meet the standards in § 152.045(C)(3);
(b) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy; and
(c) Be certified by a registered professional engineer or architect that the standards of this division are satisfied. Such certifications shall be provided to the Floodplain Administrator.
(4) Require for all new construction and substantial improvements of non-residential structures or fully enclosed areas below the lowest floor, that are useable 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 designed or certified by a registered engineer or architect or meet or exceed the following minimum criteria:
(a) A minimum of two openings 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;
(b) The bottom of all openings shall be no higher than one foot above grade; and
(c) Openings may be equipped with screens, louvers, valves or other coverings or devices provided that they permit the automatic entry and exit of floodwaters, as certified by the owner's engineer.
(5) Manufactured homes shall meet the above standards and also the standards in § 152.049.
(6) Fill, if used to elevate structures, must meet all of the following standards:
(a) The top of such fill shall be at no point lower than the regulatory flood elevation;
(b) The fill shall extend at least 15 feet beyond the walls or supporting frame of the structure;
(c) Fill must be placed and compacted in accordance with the International Building Code, 2012 edition;
(d) Fill shall not interfere with local drainage or tributary flow to the channel of any watercourse; and
(e) Fill proposed in excess of the volume and extent required herein must be shown to have no detrimental effect and the amount of fill cannot be greater than is necessary to achieve the purpose for which it is intended as demonstrated by a plan submitted by the applicant indicating the uses to which the filled land will be put and the final dimensions and extent of the proposed fill. Fill shall not include junk, trash, wood or other buoyant or hazardous material and shall be protected as needed against scour and erosion by riprap or other protective measures as approved by the Floodplain Administrator.
(Ord. 2019-863, passed 1-8-2019)