(A) In addition to the damage prevention requirements of § 151.14, all buildings to be located in the SFHA shall be protected from flood damage below the FPE. This building protection requirement applies to the following situations:
(1) Construction or placement of a new building valued at more than $1,000;
(2) Structural alterations made to an existing building that increase the floor area by more than 20%, or the market value of the building by more than 50%;
(3) Reconstruction or repairs made to a damaged building that are valued at or more than 50% of the market value of the building before the damage occurred;
(4) Installing a manufactured home on a new site or a new manufactured home on an existing site. This chapter does not apply to returning a manufactured home to the same site it lawfully occupied before it was removed to avoid flood damage; and
(5) Installing a travel trailer on a site for more than 180 days.
(B) This building protection requirement may be met by one of the following methods. The Building Official shall maintain a record of compliance with these building protection standards as required in § 151.14.
(C) A residential or nonresidential building may be constructed on permanent landfill in accordance with the following.
(1) The fill shall be placed in layers no greater than one foot deep before compaction.
(2) The lowest floor (including basement) shall be at or above the FPE. The fill should extend at least ten feet beyond the foundation of the building before sloping below the FPE.
(3) The fill shall be protected against erosion and scour during flooding by vegetative cover, riprap or bulk heading. If vegetative cover is used, the slopes shall be no steeper than three horizontal to one vertical.
(4) The fill shall not adversely affect the flow of surface drainage from or onto neighboring properties.
(D) A residential or nonresidential building may be elevated in accordance with the following:
(1) The building or improvements shall be elevated on crawl space, walls, stilts, piles or other foundation, provided:
(a) The walls have permanent openings no more than one foot above grade; and
(b) The walls and floor are not subject to damage by hydrostatic pressures associated with the base flood.
(2) The foundation and supporting members shall be anchored and aligned in relation to flood flows and adjoining structures so as to minimize exposure to known hydrodynamic forces such as current, waves, ice and floating debris; and
(3) All areas below the FPE shall be constructed of materials resistant to flood damage. The lowest floor (including basement) and all electrical, heating, ventilating, plumbing and air-conditioning equipment and utility meters shall be located at or above the FPE. Water and sewer pipes, electrical and telephone lines, submersible pumps and other waterproofed service facilities may be located below the FPE.
(E) Manufactured homes and travel trailers to be installed on a site for more than 180 days shall be:
(1) Elevated at or above the FPE in accordance with division (C) above; and
(2) Anchored to resist flotation, collapse or lateral movement by being tied down in accordance with the Rules and Regulations for the Illinois Mobile Home Tie-Down Act issued pursuant to Ill. Rev. Stat. Ch. 1111, §§ 4401 through 4406.
(F) Only a nonresidential building may be floodproofed in accordance with the following.
(1) A registered professional engineer shall certify that the building has been designed so that below the FPE, the structure and attendant utility facilities are watertight and capable of resisting the effects of the base flood. The building design shall take into account flood velocities, duration, rate of rise, hydrostatic and hydrodynamic forces, the effects of buoyancy and impacts from debris and ice.
(2) Floodproofing measures shall be operable without human intervention and without an outside source of electricity.
(1986 Code, § 22.12.150) (Ord. 1291, passed - -1986)