In addition to the damage prevention requirements of § 151.07, all buildings to be located in the SFHA shall be protected from flood damage below the FPG.
(A) This building protection requirement applies to the following situations:
(1) Construction or placement of any new building valued at more than $1,000; or greater than 400 square feet, whichever is less;
(2) Structural alterations made to an existing building that increase the market value of the building by more than 50% (excluding the value of the land);
(3) Any subsequent alterations;
(4) Reconstruction or repairs made to a damaged building that are valued at or more than 50% of the market value of the building (excluding the value of the land) before damage occurred;
(5) Installing a manufactured home on a new site or a new manufactured home on an existing site. This chapter does not apply to returning the existing manufactured home to the same site it lawfully occupied before it was removed to avoid flood damage; and
(6) Installing a travel trailer or recreational vehicle on a site for more than 180 days.
(B) This building protection requirement may be met by one of the following methods. The Zoning Administrator shall maintain a record of compliance with these building protection standards as required in § 151.04.
(1) A residential or nonresidential building may be constructed on a permanent landfill in accordance with the following.
(a) The fill shall be placed in layers no greater than one foot deep before compacting to 95% of the maximum density obtainable with the Standard Proctor Test method.
(b) The fill should extend at least ten feet beyond the foundation of the building before sloping below the FPG.
(c) The fill shall be protected against erosion and scour during flooding by vegetative cover, riprap or bulkheading. If vegetative cover is used, the slopes shall be no steeper than three horizontal to one vertical.
(d) The fill shall not adversely affect the flow of surface drainage from or onto neighboring properties.
(e) The top of the lowest floor including basements, (see definition of LOWEST FLOOR in § 151.03) shall be at or above the FPG.
(2) A residential or nonresidential building may be elevated in accordance with the following.
(a) The building or improvements shall be elevated on posts, piers, columns, extended walls, or other types of similar foundation provided:
1. Walls of any enclosure below the elevated floor shall be designed to automatically equalize hydrostatic flood forces on the walls by allowing for the entry and exit of flood waters, through providing a minimum of two openings (in addition to doorways and windows) having a total area of one square foot for every two square feet of enclosed area subject to flooding. The bottom of all such opening shall be no higher than one foot above grade; and
2. Any enclosure below the elevated floor is used for storage of vehicles and building access.
(b) 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 buoyancy, current, waves, ice and floating debris.
(c) All areas below the FPG shall be constructed of materials resistant to flood damage. The top of lowest floor (including basement) and all electrical, heating, ventilating, plumbing and air conditioning equipment and utility meters shall be located at or above the FPG. Water and sewer pipes, electrical and telephone lines, submersible pumps and other waterproofed service facilities may be located below the FPG.
(3) Manufactured homes and recreational vehicles to be installed or substantially improved on a site for more than 180 days must meet one of the following anchoring requirements.
(a) The manufactured home shall be elevated on a permanent foundation such that the lowest floor shall be at or above the FPG and securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement. This requirement applies to all manufactured homes to be placed on a site:
1. Outside a manufactured home park or subdivision;
2. In a new manufactured home park or subdivision;
3. In an expansion to an existing manufactured home park or subdivision; or
4. In an existing manufactured home park or subdivision on which a manufactured home has incurred “substantial damage” as a result of a flood.
(b) 1. This requirement applies to all manufactured homes to be placed on a site in an existing manufactured home park or subdivision that has not been substantially damaged by a flood.
2. The manufactured home shall be elevated so that the lowest floor of the manufactured home chassis is supported by reinforced piers or other foundation elements that are no less than 36 inches in height above grade and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement.
(4) Recreational vehicles placed on a site shall either:
(a) Be on the site for less than 180 consecutive days;
(b) Be fully licensed and ready for highway use (defined as being on its wheels or jacking system, is attached to the site only by quick disconnect type utilities and security devices, and has no permanently attached additions); or
(c) Meet the requirements for “manufactured homes” in division (B)(3) above.
(5) A nonresidential building may be floodproofed to the FPG (in lieu of elevating) if done in accordance with the following.
(a) A registered professional engineer shall certify that the building has been designed so that below FPG, the structure and attendant utility facilities are water-tight and capable of resisting the effects of the regulatory flood. The building design shall take into account flood velocities, duration, rate of rise, hydrostatic pressures and impacts from debris or ice.
(b) Floodproofing measures shall be operable without human intervention and without an outside source of electricity.
(Ord. 94-7, passed 8-1-1994)