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(A) General standards. In all areas of special flood hazards, the following provisions are required for all new construction and substantial improvements:
(1) All new construction or substantial improvements shall be designed (or modified) and adequately anchored to prevent flotation, collapse, or lateral movement of the structure resulting from hydrodynamic and hydrostatic loads, including the effects of buoyancy;
(2) All new construction or substantial improvements shall be constructed by methods and practices that minimize flood damage;
(3) All new construction or substantial improvements shall be constructed with materials resistant to flood damage;
(4) All new construction or substantial improvements shall be constructed with electrical, heating, ventilation, plumbing, and air conditioning equipment and other service facilities that are designed and/or located a minimum of two feet above the base flood elevation;
(5) All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of, flood waters into the system;
(6) New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of flood waters into the system and discharge from the systems into flood waters; and
(7) On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
(1) Residential construction. New construction and substantial improvement of any residential structure shall have the lowest floor (including basement), elevated to at least two feet above the base flood elevation. A registered professional engineer, architect, or land surveyor shall submit a certification to the Floodplain Administrator that the standard of this division as proposed in § 151.13(C)(1)(a) is satisfied.
(2) Nonresidential construction. New construction and substantial improvements of any commercial, industrial or other nonresidential structure, including attendant utilities and sanitary facilities, shall either have the lowest floor (including basement) elevated to a minimum of two feet above the base flood elevation. A registered professional engineer or architect shall develop and/or review structural design, specifications, and plans for the construction and shall certify that the design and methods of construction are in accordance with accepted standards of practice as outlined in this division. A record of such certification which includes the specific elevation (in relation to mean sea level) to which such structures are floodproofed shall be maintained by the Floodplain Administrator.
(3) Enclosures. New construction and substantial improvements, with fully enclosed areas below the lowest floor 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 architect or meet or exceed the following minimum criteria:
(a) A minimum of two openings having a total net area of not less than one square inch for every square foot of enclosed area subject to flooding shall be provided.
(b) The bottom of all openings shall be no higher than one foot above grade.
(c) Openings may be equipped with screens, louvers, valves, or other coverings or devices provided that they permit the automatic entry and exit of floodwaters.
(4) Manufactured homes.
(a) All manufactured homes to be placed within Zone A on a community’s FHBM or FIRM shall be installed using methods and practices which minimize flood damage. For the purpose of this requirement, manufactured homes must be elevated and anchored to resist 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 requirement is in addition to applicable state and local anchoring requirements for resisting wind forces.
(b) Require that manufactured homes that are placed or substantially improved within Zones A1-30, AH, and AE on the community’s FIRM on sites (i) outside of a manufactured home park or subdivision, (ii) in a new manufactured home park or subdivision, (iii) in an expansion to an existing manufactured home park or subdivision, or (iv) in an existing manufactured home park or subdivision on which a manufactured home has incurred ‘substantial damage’ as a result of a flood, be elevated on a permanent foundation such that the lowest floor of the manufactured home is elevated to or above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse, and lateral movement.
(c) Require that manufactured homes be placed or substantially improved on sites in an existing manufactured home park or subdivision with Zones A1-30, AH and AE on the community’s FIRM that are not subject to the provisions of division (B)(4) of this section be elevated so that either:
1. The lowest floor of the manufactured home is two feet above the base flood elevation; and
2. The manufactured home chassis is supported by reinforced piers or other foundation elements of at least equivalent strength 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.
(d) Prohibit the placement of any manufactured housing within the areas which have been identified as regulatory floodways.
(5) Recreational vehicles. Require that recreational vehicles placed on sites within Zones A1-30, AH, and AE on the community’s FIRM either (i) be on the site for fewer than 180 consecutive days, or (ii) be fully licensed and ready for highway use, or (iii) meet the permit requirements of Article 4, Section C(1) and the elevation and anchoring requirements for “manufactured homes” in division (B)(4) of this section. A recreational vehicle is ready for highway use if it is 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.
(C) Standards for subdivision proposals.
(3) Base flood elevation data shall be generated for subdivision proposals and other proposed development including manufactured home parks and subdivisions which is greater than 50 lots or five acres, whichever is lesser, if not otherwise provided pursuant to §§ 151.07 or division (B)(8) of this section.
(4) All subdivision proposals including manufactured home parks and subdivisions shall have adequate drainage provided to reduce exposure to flood hazards.
(5) All subdivision proposals, including manufactured home parks and subdivisions, shall have public utilities and facilities such as sewer, gas, electrical, and water systems located and constructed to minimize or eliminate flood damage.
(D) Standards for areas of shallow flooding (AO/AH Zones). Located within the areas of special flood hazard established in § 151.07 of this chapter are areas designated as shallow flooding. These areas have special flood hazards associated with base flood depths of one to three feet where a clearly defined channel does not exist and where the path of flooding is unpredictable and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow; therefore, the following provisions apply:
(1) All new construction and substantial improvements of residential structures have the lowest floor (including basement) elevated a minimum of two feet above the base flood elevation.
(2) All new construction and substantial improvements of nonresidential structures:
(a) Have the lowest floor (including basement and attendant utility and sanitary facilities) elevated to a minimum of two feet above the base flood elevation.
(3) A registered professional engineer or architect shall submit a certification to the Floodplain Administrator that the standards of this section, as proposed in § 151.13(C)(1)(a), are satisfied.
(4) Require within Zones AH or AO adequate drainage paths around structures on slopes to guide flood waters around and away from proposed structures.
(E) Floodways. Floodways located within areas of special flood hazards established in § 151.07 are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of flood waters which carry debris, potential projectiles and erosion potential, the following provisions shall apply:
(1) Encroachments are prohibited, including fill, new construction, substantial improvements and other development within the adopted regulatory floodway unless it has been demonstrated through hydrologic and hydraulic analyses performed in accordance with standard engineering practice that the proposed encroachment would not result in any increase in flood levels within the community during the occurrence of the base flood discharge.
(2) If division (1) above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this section.
(3) Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Program Regulation, a community may permit encroachments within the adopted regulatory floodway that would result in an increase in base flood elevations, provided that the community first completes all of the provisions required by Section 65.12.
('68 Code, § 6-83) (Ord. 3-1987-20, passed 3-10-87; Am. Ord. 11- 2012-68, passed 11-29-12; Am. Ord. 06-2022-47, passed 6-14-22) Penalty, see § 151.99