(a) General requirements. Special permit uses in the floodplain may be permitted only where existing streets or utilities are at elevations which make construction outside the horizontal limits of the floodplain impractical, or in other special circumstances.
(1) Structures shall ordinarily be located outside the horizontal limits of the flood plain and at least two (2) feet above the elevation of the regulatory flood, but may be allowed, as a special permit use, to be elevated or floodproofed to a point above the regulatory flood protection elevation.
(2) Such structures shall be limited to those that will not be subject to substantial flood damage, and which will not substantially affect the capacity of any stream or increase the regulatory flood elevation.
(3) All special permit uses shall be located outside the horizontal limits of the vegetative buffer strip.
(4) A licensed professional engineer 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 for meeting the requirements herein.
(5) Such certification, including the specific elevation (in relation to mean sea level) to which such structure is elevated or floodproofed, shall be provided to the City Engineer as a part of the application for the special permit.
(b) Manufactured homes. Any manufactured home permitted in any floodplain as a special permit use shall be elevated so as to be at or above the regulatory flood protection elevation, and anchored to resist flotation, collapse or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top and frame ties to ground anchors. Federal Emergency Management Agency Manual (FEMA #85), "Manufactured Home Installation in Flood Hazard Areas," published in September 1985, shall be the basis for determination of compliance with this section. This requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.
(c) Floodproofed buildings. New construction or substantial improvement of an existing structure for business, office, industrial or other non-residential use, so as to be floodproofed, shall be permitted as a special permit use; provided that below the regulatory flood protection elevation the structure is watertight, with walls substantially impermeable to the passage of water, and with the structural components capable of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy.
(d) New structures on fill. New construction or substantial improvement of an existing structure on fill shall be permitted as a special permit use, provided the lowest floor and the lowest opening are at or above the regulatory flood protection elevation. Such fill shall be at least one (1) foot above the regulatory flood elevation for the particular area, and shall extend at that same elevation towards the stream channel for a distance of at least fifteen (15) feet beyond the limits of the structure thereon. However, no use shall be constructed which adversely affects the capacity of streams or floodplains of any main stream or tributary to the main stream, drainage ditch, or any other drainage facility or system, or will increase the regulatory flood elevation.
(e) Elevated buildings. New construction or substantial improvements of elevated buildings, which 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 to allow for the entry and exit of floodwaters to automatically equalize hydrostatic flood forces on exterior walls. Designs for complying with this requirement must be certified by a licensed professional engineer, and shall meet the following minimum criteria:
(1) The structure shall have a minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding;
(2) The bottom of all openings shall be no higher than one (1) foot above grade;
(3) Openings may be equipped with screens, louvers, valves or other coverings or devices, provided they permit the automatic flow of floodwaters in both directions;
(4) Electrical, plumbing and other utility connections are prohibited below the regulatory flood protection elevation;
(5) Access to the enclosed area shall be the minimum necessary to allow for parking of vehicles (garage door) and the limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator); and
(6) The interior portion of such enclosed area shall not be partitioned or finished into separate rooms.
(f) Temporary parking areas and parking structures. Temporary parking areas and elevated parking structures shall be permitted in the floodplain as special permit uses.
(g) Other uses. Uses such as tennis courts, for which fences are an integral requirement, shall be permitted as a special permit use in the floodplain. All fences must be designed and located to minimize obstruction of the floodplain. Swimming pools shall not be permitted in the floodplain.
(Ord. No. 1675, 2-28-05)