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 and hydrostatic loads, including the effects of buoyancy; and
2. All manufactured homes shall meet the anchoring standards of Section 11-1-5-5.
B. Construction Materials and Methods:
1. All new construction and substantial improvements shall be constructed with materials resistant to flood damage;
2. All new construction and substantial improvements shall be constructed using methods and practices that minimize flood damage; and
3. All new construction and substantial improvement 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.
C. Elevation and Floodproofing:
1. Residential Construction:
a. Residential construction, new or substantial improvement, shall have the lowest floor, including basement, elevated to or above the Base Flood Elevation.
b. Where the Base Flood Elevation has not been determined, the Base Flood Elevation is determined locally by the criteria set out in Section 11-1-4-2.B. A minimum of 2 feet above highest adjacent grade may result in a lower insurance premium.
c. A garage attached to a residential structure, constructed with the garage floor slab below the Base Flood Elevation, must be designed to allow for the automatic entry and exit of flood waters. See Section 11-1-5-1.C.4.
d. Upon completion of the structure, certification by a registered professional engineer or surveyor that the elevation requirements of the lowest floor, including basement, of this section have been satisfied shall be provided to the Floodplain Administrator for verification.
2. Non-residential Construction:
a. Non-residential construction, new or substantial improvement, shall have the lowest floor either elevated to conform with division C.1. of this section,
b. Or, together with attendant utility and sanitary facilities,
(1) Be floodproofed below the elevation recommended under division C.1. of this section so that the structure is watertight with walls substantially impermeable to the passage of water; and
(2) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy.
c. 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 meeting the provisions listed above.
d. Upon completion of the structure, certification by a registered professional engineer or surveyor that the elevation requirements of the lowest floor, including basement, of this section have been satisfied shall be provided to the Floodplain Administrator for verification; or certification by a registered professional engineer or architect that the floodproofing design of this section is satisfied, including the specific elevation in relation to mean sea level to which such structures are floodproofed, shall be provided to the Floodplain Administrator for verification.
3. Appurtenant Structures (Detached Garages And Storage Structures): Appurtenant structures used solely for parking of vehicles or storage may be constructed such that the floor is below the Base Flood Elevation, provided the structure is designed and constructed in accordance with the following requirements:
a. Use of the appurtenant structure must be limited to parking of vehicles or storage;
b. The portions of the appurtenant structure located below the Base Flood Elevation must be built using flood resistant materials;
c. The appurtenant structure must be adequately anchored to prevent flotation, collapse and lateral movement;
d. Any machinery or equipment servicing the appurtenant structure must be elevated or floodproofed to or above the Base Flood Elevation; and
e. The appurtenant structure must be designed to allow for the automatic entry and exit of flood waters in accordance with division C.4. of this section.
Detached garages, storage structures and other appurtenant structures not meeting the above standards must be constructed in accordance with all applicable standards in division C.1. of this section.
Upon completion of the structure, certification that the requirements of this section have been satisfied shall be provided to the Floodplain Administrator for verification.
4. Flood Openings: All new construction and substantial improvement with fully enclosed areas below the lowest floor (excluding basements) that are usable solely for parking of vehicles, building access or storage, and which are subject to flooding, shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the automatic entry and exit of floodwater. Designs for meeting this requirement must meet or exceed the following criteria:
For non-engineered openings:
a. Have a minimum of two openings with a total net area of not less than one square inch for every square foot of enclosed area subject to flooding;
b. The bottom of all openings shall be no higher than one foot above grade;
c. Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwater.
Alternatively, a registered engineer or architect may design and certify engineered openings.
Upon completion of the structure, certification that the requirements of this section have been satisfied shall be provided to the Floodplain Administrator for verification. (Ord. 302, 1-19-2021)