Discussion and Review of Tiffin Municipal Code Revisions – Preparation for Setting the Public Hearing — Tiffin City Code - DRAFT

CHAPTER 160 FLOODPLAIN MANAGEMENT designated, no development may increase the Base Flood Elevation more than one (1) foot. The applicant will be responsible for providing the Department of Natural Resources with sufficient technical information to make such determination. A. All Development. All development within the Special Flood Hazard Areas shall: (1) Be designed and adequately anchored to prevent flotation, collapse, or lateral movement. (2) Use construction methods and practices that will minimize flood damage. (3) Use construction materials and utility equipment that are resistant to flood damage. B. Residential Structures. All new or substantially improved residential structures shall have the lowest floor, including basement, elevated a minimum of one (1) foot above the Base Flood Elevation. Construction shall be upon compacted fill which shall, at all points, be no lower than one (1) foot above the Base Flood Elevation and extend at such elevation at least eighteen (18) feet beyond the limits of any structure erected thereon. Alternate methods of elevating (such as piers or extended foundations) may be allowed subject to favorable consideration by the Council, 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. All new residential structures located in areas that would become isolated due to flooding of surrounding ground shall be provided with a means of access that will be passable by wheeled vehicles during the base flood. C. Nonresidential Structures. All new or substantially improved nonresidential structures shall have the lowest floor (including basement) elevated a minimum of one (1) foot above the Base Flood Elevation, or together with attendant utility and sanitary systems, be floodproofed to such a level. When floodproofing is utilized, a professional engineer registered in the State shall certify that the floodproofing methods used are adequate to withstand the flood depths, pressures, velocities, impact, and uplift forces, and other factors associated with the base flood; and that the structure, below the Base Flood Elevation is watertight with walls substantially impermeable to the passage of water. A record of the certification indicating the specific elevation (in relation to North American Vertical Datum 1988) to which any structures are floodproofed shall be maintained by the Administrator. D. All New and Substantially Improved Structures. (1) Fully enclosed areas below the lowest floor (not including basements) that are subject to flooding shall be designed to automatically equalize hydrostatic flood forces on exterior walls by allowing for the entry and exit of floodwaters. Designs for meeting this requirement must either be certified by a registered professional engineer or meet or exceed the following minimum criteria: CODE OF ORDINANCES, TIFFIN, IOWA - 1412 -