Section 1612, Flood Loads, of the IBC, is hereby amended by adding the following sections:
Section 1612.1.1 General Floodplain Construction Standards. The following standards are established for construction occurring within the one-hundred-year flood elevation:
A. All Structures shall:
a. Be adequately anchored to prevent flotation, collapse or lateral movement of the structure;
b. Be constructed with materials and utility equipment resistant to flood damage; and
c. Be constructed by methods and practices that minimize flood damage.
B. Residential buildings: All new or substantially improved residential structures shall have the lowest floor, including basement, elevated a minimum of one foot above the one-hundred-year flood level. Construction shall be upon compacted fill which shall, at all points, be no lower than one floor above the one-hundred-year flood level and extend at such elevation at least eighteen feet beyond the limits of any structure erected thereon. Alternate methods of elevating (such as piers) may be allowed, subject to favorable consideration by the Code Official where existing topography, street grades, or other factors preclude elevating by fill. In such cases, the methods used must be adequate to support the structure as well as withstand the various forces and hazards associated with flooding.
C. Nonresidential buildings: All new or substantially improved nonresidential buildings shall have the first floor (including basement) elevated a minimum of one foot above the one-hundred-year flood level, or together with attendant utility and sanitary systems, be flood-proofed to such a level.
D. When flood-proofing is utilized, a professional engineer registered in the State of Iowa shall certify that the flood-proofing methods uses are adequate to withstand the flood depths, pressures, velocities, impact and uplift forces and other factors associated with the one-hundred-year flood; that the structure, below the one-hundred-year flood level, is watertight will walls substantially impermeable to the passage of water. A record of the certification indicating the specific elevation (in relation to mean sea level) to which any structures are flood-proofed shall be maintained by the Code Official.
E. Mobile homes shall be anchored to resist flotation, collapse, or lateral movement by providing over-the-top and frame ties to ground anchors. Specific requirements are that:
a. Over-the-top ties be provided at each of the four corners of the mobile home with two additional ties per side at intermediate locations for mobile homes 50 feet or more in length or one such tie for mobile homes less than 50 feet in length;
b. Frame ties be provided at each corner of the home with five additional ties per side at intermediate points for mobile homes 50 feet in length.
c. All components of the anchoring system be capable of carrying a force of four thousand eight hundred pounds; and
d. Any additions to the mobile home be similarly anchored.
F. Mobile homes shall be placed on lots or pads elevated by means of compacted fill so that the lowest floor of the mobile home will be a minimum of one foot above the one-hundred-year flood level. In addition, the tie-down specification of Section 175.04.350 Section E must be met and adequate surface drainage and access for a hauler must be provided.
G. New mobile homes, expansions to existing mobile homes and mobile home lots where the repair, reconstruction or improvement of the streets, utilities, and pads equals or exceeds fifty percent before the repair, reconstruction or improvement has commenced shall provide:
a. Lots or pads that have been elevated by means of compacted fill so that the lowest floor of mobile homes will be a minimum of one-foot above one-hundred-year flood level;
b. Ground anchors for mobile homes.
H. Storage of materials and equipment that are flammable, explosive or injurious to human, animal or plant life is prohibited unless elevated a minimum of one foot above the one-hundred-year flood level. Other material and equipment must either be similarly elevated or:
a. Not be subject to major flood damage and be anchored to prevent movement due to flood waters; or
b. Be readily removable from the area within the time available after flood warning.
Section 1612.1.2 Special Floodway Standards. The following standards are established for construction occurring within a designated floodway:
A. Structures, buildings and sanitary and utility systems, if permitted, shall meet the applicable general floodplain standards and shall be constructed or aligned to present the minimum possible resistance to flood flows.
B. Buildings, if permitted, shall have a low flood damage potential and shall not be for human habitation.