(A) Residential construction. In Special Flood Hazard Areas A and AE, new construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to one foot above base flood elevation. All new construction, substantial improvements, and repair to structures that have sustained substantial damage which are residential structures shall have the bottom of the lowest floor, including basement, elevated one foot above the base flood elevation (BFE). Electrical, plumbing, machinery or other utility equipment that service the structure must be elevated one foot above the BFE.
(B) Nonresidential construction. In Special Flood Hazard Areas A and AE, all new construction, substantial improvements, and repair to structures that have sustained substantial damage which are commercial, industrial or non-residential structures shall:
(1) Have the bottom of the lowest floor, including basement, elevated one foot above the base flood elevation (BFE); or;
(2) In lieu of being elevated, non-residential structures may be dry floodproofed to one foot above the BFE provided that together with all attendant utilities and sanitary facilities the areas of the structure below the required elevation are watertight with walls substantially impermeable to the passage of water, and provided that such structures are composed of structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effects of buoyancy. A registered professional engineer or architect shall review and/or develop structural design specifications and plans for the construction, and shall certify that the design and methods of construction are in accordance with acceptable standards of practice for meeting the provisions of this chapter. Such certification shall be provided to the zoning official on the FEMA Floodproofing Certificate, Form 086-0-34.
(3) Electrical, plumbing, machinery or other utility equipment that service the structure must be elevated one foot above the BFE.
(C) Fully enclosed areas below the base flood elevation of elevated buildings. In Special Flood Hazard Areas A and AE, all new construction, substantial improvements, or repair to structures that have sustained substantial damage, whether residential or non-residential, that include fully enclosed areas formed by a foundation and other exterior walls shall have the lowest floor elevated to one foot above the base flood elevation (BFE). The elevated building shall be designed to preclude finished living space below the lowest floor and be designed to allow for the entry and exit of flood waters to automatically equalize hydrostatic flood forces on exterior walls (wet floodproofing). Designs for complying with this requirement must either be certified by a registered professional engineer or architect as meeting the requirements of ASCE 24 § 2.6.2.2, or meet the following minimum criteria listed in divisions (C) (1) through (8) below:
(1) Provide a minimum of two openings (hydraulic flood vents) having a total net area of not less than one square inch for every one square foot of enclosed area subject to flooding. The enclosed area is measured on the exterior of the enclosure walls. These hydraulic openings must be located on at least two different exterior walls of each enclosed area. If the structure has more than one enclosed area, openings must be installed in the exterior walls of each enclosed area so that flood waters can enter directly from the outside;
(2) The bottom of all openings shall be no higher than one foot above the higher of either the final interior grade or floor elevation, or the finished exterior grade adjacent to the outside of the foundation wall. At least one entire side of the structure's fully enclosed area must be at or above grade. Fill placed around the foundation walls must be graded so that the elevation inside the enclosed area is equal to or higher than the adjacent outside elevation on at least one side of the building. The finished floor of the enclosed area shall be no lower than the bottom of the foundation openings. The foundation slab of a residential structure, including the slab of a crawlspace, must be set equal to the outside finished grade on at least one side of the building;
(3) The openings may be equipped with screens, louvers, valves or other coverings or devices provided they permit the automatic entry and exit of flood waters in both directions without any external influence or control such as human intervention, including the use of electrical and other non-automatic mechanical means. These coverings must not block or impede the automatic flow of floodwaters into and out of the enclosed area. Other coverings may be designed and certified by a registered professional engineer or approved by the [title of local administrator];
(4) Openings shall not be less than three inches in any direction in the plane of the wall;
(5) The area cannot be used as finished living space. Use of the enclosed area shall be the minimum necessary and shall only be used for the parking of vehicles, building access or limited storage. Access to the enclosed area shall be the minimum necessary to allow for the parking of vehicles (garage door) or limited storage of maintenance equipment used in connection with the premises (standard exterior door) or entry to the living area (stairway or elevator). The enclosed area shall not be used for human habitation;
(6) All interior walls, floor, and ceiling materials located below one foot above the BFE shall be unfinished and flood damage-resistant in accordance with FEMA Technical Bulletin 2, Flood Damage-Resistant Requirements.
(7) Electrical, plumbing, HVAC duct work, machinery or other utility equipment and connections that service the structure (including, but not limited to, furnaces, oil or propane tanks, air conditioners, heat pumps, hot water heaters, ventilation, washer and dryer hook-ups, electrical junction boxes, circuit breaker boxes and food freezers) are prohibited in the fully enclosed area below the BFE plus one foot. Utilities or service equipment located in this enclosed area, even if elevated to one foot above the BFE in the space, may subject the structure to increased flood insurance rates.
(8) A residential building with a structurally attached garage having the floor slab below the BFE is considered an enclosed area below the BFE and must meet the standards of § 151.66(C)(1) through (7) above. A garage attached to a residential structure, constructed with the garage floor slab below the BFE, must be designed to allow for the automatic entry and exit of floodwaters in both directions. Flood openings or vents are required in the exterior walls of the garage or in the garage doors. Garage doors that must be manually opened do not meet the flood vent requirements in § 151.66(C)(1) through (3). In addition to the automatic entry of floodwaters, the areas of the garage below BFE plus one foot must be constructed with flood damage-resistant materials per the requirements of FEMA Technical Bulletin 2. Garages attached to non-residential structures must also meet the aforementioned requirements or be dry floodproofed as per the requirements of § 151.66(B).
(D) Manufactured homes and recreational vehicles.
(1) In Special Flood Hazard Areas (SFHA) with Zones A and AE, any manufactured (mobile) home to be newly placed, undergoing a substantial improvement or repaired as a result of substantial damage, shall be elevated so that the bottom of the frame is located one foot above the base flood elevation (BFE). The manufactured home must also meet all the construction standards for Zones A and AE as per §§ 151.66 and 151.65. The foundation and anchorage of manufactured homes to be located in floodways shall be designed and constructed in accordance with ASCE 24. This includes SFHAs outside a manufactured home park or subdivision, in a new manufactured home park or subdivision, in an existing manufactured home park or subdivision, in an expansion to an existing manufactured home park or subdivision, or on a site in an existing manufactured home park in which a manufactured home has incurred substantial damage as a result of a flood.
(2) In Special Flood Hazard Areas (SFHA) with Zones VE and Coastal AE, any manufactured (mobile) home to be newly placed, undergoing a substantial improvement or repaired as a result of sustained substantial damage, shall be elevated so that the bottom of the lowest horizontal structural member located one foot above the base flood elevation (BFE). The manufactured home must also meet all the construction standards for Zones VE and Coastal AE as per § 151.67. This includes SFHAs outside a manufactured home park or subdivision, in a new manufactured home park or subdivision, in an existing manufactured home park or subdivision, in an expansion to an existing manufactured home park or subdivision, or on a site in an existing manufactured home park in which a manufactured home has incurred substantial damage as a result of a flood.
(3) All manufactured (mobile) homes within SFHA shall be placed on a permanent foundation which itself is securely anchored and to which the structure is securely anchored so that it will resist flotation, lateral movement and hydrostatic pressures. Anchoring may include, but not be limited to, the use of over-the-top or frame ties to ground anchors.
(4) All manufactured (mobile) homes within SFHA shall be installed using methods and practices that minimize flood damage. Adequate access and drainage should be provided. Elevation construction standards include piling foundations placed no more than ten feet apart, and reinforcement is provided for piers more than six feet above ground level.
(5) Recreational vehicles placed on sites within Zones A and AE in the SFHA shall either be on the site for fewer than 180 consecutive days, and be fully licensed and ready for highway use, or meet all the general standards of § 151.65 and the elevation and anchoring requirement of §§ 151.66, 151.65(A) and 151.66(D)(3). 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.
(6) Recreational vehicles placed on sites within Zone VE and Coastal AE in the SFHA shall either be on the site for fewer than 180 consecutive days, and be fully licensed and ready for highway use, or meet all the general standards of § 151.65, the VE and Coastal AE Zone construction requirements of § 151.67, and the elevation and anchoring requirement of §§ 151.67, 151.65(A) and 151.66(D)(3). 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.
(Ord. passed 6-22-1981; Ord. passed 12-19-1988; Ord. passed 5-31-2022)
Editor’s note:
TM Volume 14, page 122; TM Volume 16, page 262, Amended