Chapter 160 – Flood Plain Regulations

C. New or replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system. Water supply treatment facilities other than on-site systems shall be provided with a level of protection equal to or greater than one foot above the 100-year flood elevation. D. Utilities such as gas or electrical systems shall be located and constructed to minimize or eliminate flood damage to the system and the risk associated with such flood damaged or impaired systems. 7. Flammable or Explosive Materials. Storage of equipment and materials that are flammable, explosive, or injurious to human, animal or plant life is prohibited unless elevated a minimum of one foot above the 100-year flood level. Other material and equipment must either be similarly elevated or: (i) not subject to major flood damage and anchored to prevent movement due to floodwaters; or (ii) readily removable from the area within the time available after flood warning. 8. Levees and Floodwalls. Flood control structural works such as levees, floodwalls, etc. shall provide, at a minimum, protection from a 100-year flood with a minimum of three feet of design freeboard and shall provide for adequate interior drainage. In addition, structural flood control works shall be approved by the Department of Natural Resources. 9. Watercourse Alterations. Watercourse alterations or relocations must be designed to maintain the flood carrying capacity within the altered or relocated portion. In addition, such alterations or relocations must be approved by the Department of Natural Resources. 10. Subdivisions. Subdivisions (including factory-built home parks and subdivisions) shall be consistent with the need to minimize flood damages and shall have adequate drainage provided to reduce exposure to flood damage. Development associated with subdivision proposals (including the installation of public utilities) shall meet the applicable performance standards of this chapter. Subdivision proposals intended for residential use shall provide all lots with a means of access which will be passable by wheeled vehicles during the 100-year flood. Proposals for subdivisions greater than five acres or 50 lots (whichever is less) shall include 100-year flood elevation data for those areas located within the area of significant flood hazard. 11. Accessory Structures. A. Detached garages, sheds, and similar structures accessory to a residential use are exempt from the 100-year flood elevation requirements where the following criteria are satisfied: (1) The structure shall not be used for human habitation. (2) The structure shall be designed to have low flood damage potential. (3) The structure shall be constructed and placed on the building site so as to offer minimum resistance to the flow of floodwaters. (4) The structure shall be firmly anchored to prevent flotation which may result in damage to other structures. (5) The structure’s service facilities such as electrical and heating equipment shall be elevated or flood-proofed to at least one (1) foot above the 100-year flood level. B. Exemption from the 100-year flood elevation requirements for such a structure may result in increased premium rates for flood insurance coverage of the structure and its contents.