(B) Specifically.
(1) Residential construction.
(a) New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above base flood elevation.
(b) Fully enclosed areas below the lowest floor that are subject to flooding are prohibited, or 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 must meet or exceed the following minimum criteria.
1. 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.
2. The bottom of all openings shall be no higher than one foot above grade.
3. Openings may be equipped with screens, louvers, or other coverings or devices, provided that they permit the automatic entry and exit of floodwaters.
(2) Non-residential construction. New construction and substantial improvement of any commercial, industrial, or other non-residential structure shall either have the lowest floor, including basement, elevated to the level of the base flood elevation, or, together with attendant utility and sanitary facilities, shall:
(a) Be floodproofed so that below the base flood level the structure is watertight with walls substantial impermeable to the passage of water;
(b) Have structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy;
(c) Be certified by a registered professional engineer or architect that the design and methods of construction are in accordance with accepted standards of practice for meeting provisions of this division (B)(2) based on their development and/or review of the structural design, specifications, and plans. The certifications shall be provided to the official as set forth in § 154.22(B)(3)(b);
(d) Non-residential structures that are elevated, and not floodproofed, must meet the same standards for space below the lowest floor as described in division (B)(1)(b) above; and/or
(e) Applicants floodproofing non-residential buildings shall be notified that flood insurance premiums will be based on rates that are one foot below the floodproofed level (for example, a building constructed to the base flood level will be rated as one foot below that level).
(3) Manufactured homes. All manufactured homes to be placed or substantially improved within Zones A1-30, AH, and AE shall be elevated on a permanent foundation such that the lowest floor of the manufactured home is at or above the base flood elevation, and be securely anchored to an adequately anchored foundation system in accordance with the provisions of § 154.35(B)(1)(b).
(Prior Code, § 150.36) (Ord. 417, passed 5-4-1987)