(A) Residential construction. New construction or substantial improvement of any residential structure shall have the lowest floor, including the basement, elevated no lower than the base flood elevation. Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to facilitate the unimpeded movements of flood waters shall be provided in accordance with the standards of division (C) below.
(B) Nonresidential construction. New construction or substantial improvement of any commercial, industrial, or nonresidential structure shall have the lowest floor, including the basement, elevated no lower than the level of the base flood elevation. Structures located in all A-zones may be floodproofed in lieu of being elevated provided that all areas of the structure below the required elevation are watertight, with walls substantially impermeable to the passage of water, and use structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A registered professional engineer or architect shall certify that the standards of this division are satisfied. Such certification shall be provided to the official as set forth in § 154.31(B)(2).
(C) Elevated buildings. New construction or substantial improvements of elevated buildings that include fully enclosed areas formed by foundation and other exterior walls below the base flood elevation shall be designed to preclude finished living space and designed to allow for the entry and exit of flood waters to automatically equalize hydrostatic flood forces on exterior walls.
(1) Designs for complying with this requirement must either be certified by a professional engineer or architect or meet the following minimum criteria:
(a) Provide 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;
(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 they permit the automatic flow of flood waters in both directions.
(2) Electrical, plumbing, and other utility connections are prohibited below the base flood elevation.
(3) Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator).
(4) The interior portion of such enclosed area shall not be partitioned or finished into separate rooms.
(D) Floodways. Located within areas of special flood hazard established in § 154.07, are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles, and has erosion potential, the following provisions shall apply:
(1) Prohibit encroachments, including fill, new construction, substantial improvements, and other developments unless certification (with supporting technical data) by a registered professional engineer is provided demonstrating that encroachments shall not result in any increase in flood levels during occurrence of the base flood discharge;
(2) If division (D)(l) above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this subchapter.
(3) Prohibit the placement of manufactured homes (mobile homes), except in an existing manufactured homes (mobile homes) park or subdivision. A replacement manufactured home may be placed on a lot in an existing manufactured home park or subdivision provided the anchoring standards of § 154.20(B) and the elevation standards of division (A) of this section are met.
(Ord. 347, passed 3-10-87) Penalty, see § 154.99