(A) Residential or non-residential buildings can meet the building protection requirements by one of the following methods.
(B) The building may be constructed on permanent land fill in accordance with the following:
(1) The lowest floor (including basement) shall be at or above the flood protection elevation;
(2) The fill shall be placed in layers no greater than six inches before compaction and should extend at least ten feet beyond the foundation before sloping below the flood protection elevation;
(3) The fill shall be protected against erosion and scour during flooding by vegetative cover, riprap, or other structural measure;
(4) The fill shall be composed of rock or soil and not incorporated debris or refuse material, and
(5) The fill shall not adversely affect the flow of surface drainage from or onto neighboring properties and when necessary storm water management techniques such as swales or basins shall be incorporated.
(C) The building may be elevated on solid walls in accordance with the following:
(1) The building or improvements shall be elevated on stilts, piles, walls, crawlspace, or other foundation that is permanently open to floodwaters;
(2) The lowest floor and all electrical, heating, ventilating, plumbing, and air conditioning equipment and utility meters shall be located at or above the flood protection elevation;
(3) If walls are used, all enclosed areas below the flood protection elevation shall address hydrostatic pressures by allowing the automatic entry and exit of floodwaters. Designs must either be certified by a licensed professional engineer or by having a minimum of one permanent opening on each wall no more than one foot above grade with a minimum of two openings. The openings shall provide a total net area of not less than one square inch for every one square foot of enclosed area subject to flooding below the base flood elevation; and
(4) The foundation and supporting members shall be anchored, designed, and certified so as to minimize exposure to hydrodynamic forces such as current, waves, ice, and floating debris:
(a) All structural components below the flood protection elevation shall be constructed of materials resistant to flood damage;
(b) Water and sewer pipes, electrical and telephone lines, submersible pumps, and other service facilities may be located below the flood protection elevation provided they are waterproofed;
(c) The area below the flood protection elevation shall be used solely for parking or building access and not later modified or occupied as habitable space; and/or
(d) In lieu of the above criteria, the design methods to comply with these requirements may be certified by a licensed professional engineer or architect.
(D) The building may be constructed with a crawlspace located below the flood protection elevation; provided that the following conditions are met:
(1) The building must be designed and adequately anchored to resist flotation, collapse, and lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy;
(2) Any enclosed area below the flood protection elevation shall have openings that equalize hydrostatic pressures by allowing for the automatic entry and exit of floodwaters. A minimum of one opening on each wall having a total net area of not less than one square inch per one square foot of enclosed area. The openings shall be no more than one foot above grade;
(3) The interior grade of the crawlspace below the flood protection elevation must not be more than two feet below the lowest adjacent exterior grade;
(4) The interior height of the crawlspace measured from the interior grade of the crawl to the top of the foundations wall must not exceed four feet at any point;
(5) An adequate drainage system must be installed to remove floodwaters from the interior area of the crawlspace within a reasonable period of time after a flood event;
(6) Portions of the building below the flood protection elevation must be constructed with materials resistant to flood damage; and
(7) Utility systems within the crawlspace must be elevated above the flood protection elevation.
(Ord. 10-01, passed 7-12-2010)