Duluth UDC § 837.01

1. New construction of principal buildings (residential or non-residential), including manufactured homes, shall not be allowed within the limits of the future-conditions floodplain, unless all requirements of Sections 836.03, 836.04 and 836.05 have been met; 2. New construction or substantial improvements of existing structures shall be anchored to prevent flotation, collapse or lateral movement of the structure; 236 | P a g e Article Eight. Environmental Protection 3. New construction or substantial improvements of existing structures shall be constructed with materials and utility equipment resistant to flood damage; 4. New construction or substantial improvements of existing structures shall be constructed by methods and practices that minimize flood damage; 5. Elevated Buildings. All new construction and substantial improvements of existing structures that include any fully enclosed area located below the lowest floor formed by foundation and other exterior walls shall be designed so as to be an unfinished and flood resistant enclosure. The enclosure shall be designed to equalize hydrostatic flood forces on exterior walls by allowing for the automatic entry and exit of floodwater. a. Designs for complying with this requirement must either be certified by a professional engineer or architect or meet the following minimum criteria: i. Provide a minimum of two openings having a total net area of not less than 1 square inch for every square foot of enclosed area subject to flooding; ii. The bottom of all openings shall be no higher than 1 foot above grade; and, iii. Openings may be equipped with screens, louvers, valves or other coverings or devices provided they permit the automatic flow of floodwater in both directions. b. So as not to violate the "lowest floor" criteria of this Article, the unfinished and flood resistant enclosure shall solely be used for parking of vehicles, limited storage of maintenance equipment used in connection with the premises, or entry to the elevated area; and, c. The interior portion of such enclosed area shall not be partitioned or finished into separate rooms. 6. All heating and air conditioning equipment and components (including ductwork), all electrical, ventilation, plumbing, and other service facilities shall be designed and/or located 3 feet above the base flood elevation or 1 foot above the future-conditions flood elevation, whichever is higher, so as to prevent water from entering or accumulating within the components during conditions of flooding; 7. Manufactured homes shall be anchored to prevent flotation, collapse, or lateral movement. Methods of anchoring may include, but are not limited to, use of over-the-top or frame ties to ground anchors. This standard shall be in addition to and consistent with applicable state requirements for resisting wind forces; 8. New and replacement water supply systems shall be designed to minimize or eliminate infiltration of flood waters into the system; 9. New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the systems and discharges from the systems into flood waters; 10. On-site waste disposal systems shall be located and constructed to avoid impairment to them, or contamination from them, during flooding; and, 11. Any alteration, repair, reconstruction or improvement to a structure which is not compliant with the provisions of Code Division, shall be undertaken only if the non-conformity is not furthered, extended or replaced. 12. If the proposed development is located in multiple flood zones or multiple base flood elevation across the proposed site, the higher or more restrictive base flood elevation or future condition elevation and development standards shall take precedence. 13. All proposed development shall include adequate drainage and stormwater management facilities per the requirements of the City of Duluth to reduce exposure to flood hazards. 14. Other public utilities such as gas and electric systems shall be located and constructed to avoid impairment to them, or public safety hazards from them, during flooding. 15. When only a portion of a proposed structure is located within a flood zone or the future conditions floodplain, the entire structure shall meet the requirements of this Code Division. 237 | P a g e Article Eight. Environmental Protection 16. Subdivision proposals and other proposed new development, including manufactured home parks or subdivisions, shall be reasonably safe from flooding: a. All such proposals shall be consistent with the need to minimize flood damage within the flood- prone area; b. All public utilities and facilities, such as sewer, gas, electrical, and water systems shall be located and constructed to minimize or eliminate flood damage; and c. Adequate drainage shall be provided to reduce exposure to flood hazards.