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 elevated at least one foot above the BFE so as to prevent water from entering or accumulating within the components during conditions of flooding;
(5) 
All new and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system;
(6) 
New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the system and discharge from the systems into floodwaters; and
(7) 
On-site waste disposal systems shall be located to avoid impairment to them or contamination from them during flooding.
[Ord. No. 1182-10, § 1, 9-28-2010; Ord. No. 1386-19, § 1, 3-25-2019; Ord. No. 1474-23 adopted 6/26/2023]
In all areas of special flood hazards where base flood elevation data has been provided as set forth in: (i) division 1, section 42-37, (ii) division 2, subsection 42-62(8), or (iii) division 3, subsection 42-88(c), the following provisions are required:
(1) 
Residential construction.
New construction and substantial improvement of any residential structure shall have the lowest floor (including basement), elevated to one foot above the base flood elevation, provided, however, that the city and the floodplain administrator shall encourage the property owner to design and construct any new construction and substantial improvement of any residential structure to have the lowest floor (including basement), elevated to 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 subsection as proposed in division 2, subsection 42-64(a)(3), is satisfied.
(2) 
Nonresidential construction.
New construction and substantial improvements of any commercial, industrial or other nonresidential structure shall either have the lowest floor (including basement) elevated to one foot (1') above the base flood level plus one foot or together with attendant utility and sanitary facilities, be designed so that below the base flood level the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads and effects of buoyancy, provided, however, that the city and the floodplain administrator shall encourage the property owner to design and construct any new construction and substantial improvement of any residential structure to have the lowest floor (including basement), elevated to two feet (2') 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 subsection. 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 usable solely for parking of vehicles, building access or storage in an area other than a basement and which 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 on separate walls 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. 
Require that 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 purposes 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 one foot above the base flood elevation and be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement; provided, however, that the city and the floodplain administrator shall encourage the property owner to design and construct any new construction and substantial improvement of any residential structure to have the lowest floor (including basement), elevated to two feet above the base flood elevation.
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 subsection (4) of this section be elevated so that either:
1. 
The lowest floor of the manufactured home is at one foot (1') above the base flood elevation, provided, however, that the city and the floodplain administrator shall encourage the property owner to design and construct any new construction and substantial improvement of any residential structure to have the lowest floor (including basement), elevated to two feet (2') 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.
(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 division 2, subsection 42-64(a) , and the elevation and anchoring requirements for "manufactured homes" in subsection (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.
[Ord. No. 1182-10, § 1, 9-28-2010; Ord. No. 1386-19, § 1, 3-25-2019; Ord. No. 1474-23 adopted 6/26/2023]
(a) 
All subdivision proposals including the placement of manufactured home parks and subdivisions shall be consistent with division 1, sections 42-33, 42-34, and 42-35 of this article.
(b) 
All proposals for the development of subdivisions including the placement of manufactured home parks and subdivisions shall meet floodplain development permit requirements of division 2, sections 42-63 and 42-64; and the provisions of division 3 of this article.
(c) 
Base flood elevation data shall be generated for subdivision proposals and other proposed development including the placement of manufactured home parks and subdivisions which is greater than 50 lots or five acres, whichever is lesser, if not otherwise provided pursuant to division 1, section 42-37; division 2, subsection 42-62(8) of this article.
(d) 
Base flood elevation data shall be generated by a detailed engineering study for all zone A areas, within 100 feet of the contour lines of zone A areas, and other streams not mapped by FEMA, as indicated on the community's FIRM.
(e) 
All subdivision proposals including the placement of manufactured home parks and subdivisions shall have adequate drainage provided to reduce exposure to flood hazards.
(f) 
All subdivision proposals including the placement of 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.
[Ord. No. 1182-10, § 1, 9-28-2010; Ord. No. 1386-19, § 1, 3-25-2019]
Located within the areas of special flood hazard established in section 42-37, are areas designated as shallow flooding. These areas have special flood hazards associated with flood depths of one to three feet where a clearly defined channel does not exist, 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 shall have the lowest floor (including basement) elevated to one foot (1') above the base flood elevation or the highest adjacent grade at least as high as the depth number specified in feet on the community's FIRM (at least three feet (3') if no depth number is specified), provided, however, that the city and the floodplain administrator shall encourage the property owner to design and construct any new construction and substantial improvement of any residential structure to have the lowest floor (including basement), elevated to two feet (2') above the base flood elevation.
(2) 
All new construction and substantial improvements of nonresidential structures:
a. 
Have the lowest floor (including basement) elevated to one foot (1') above the base flood elevation or the highest adjacent grade at least as high as the depth number specified in feet on the community's FIRM (at least two feet (2') if no depth number is specified), provided, however, that the city and the floodplain administrator shall encourage the property owner to design and construct any new construction and substantial improvement of any residential structure to have the lowest floor (including basement), elevated to two feet (2') above the base flood elevation; or
b. 
Together with attendant utility and sanitary facilities be designed so that below the base specified flood depth in an AO zone, or below the base flood elevation in an AH zone level, the structure is watertight with walls substantially impermeable to the passage of water and with structural components having the capability of resisting hydrostatic and hydrodynamic loads of effects of buoyancy.
(3) 
A registered professional engineer or architect shall submit a certification to the floodplain administrator that the standards of this section, as proposed in division 2, section 42-64 are satisfied.
(4) 
Require within zones AH or AO adequate drainage paths around structures on slopes, to guide floodwaters around and away from proposed structures.
(5) 
Where BFE data are utilized in zone A, obtain and maintain records of the lowest floor and floodproofing elevations for new and substantially improved construction.
(6) 
In riverine areas, notify adjacent communities of watercourse alterations and relocations.
(7) 
Until a regulatory floodway is designated, no encroachment may increase the base flood level more than one foot.
(8) 
In zones AO and AH, require drainage paths around structures on slopes to guide water away from structures.
[Ord. No. 1182-10, § 1, 9-28-2010; Ord. No. 1386-19, § 1, 3-25-2019; Ord. No. 1474-23 adopted 6/26/2023]
Floodways located within areas of special flood hazard established in section 42-37, are areas designated as floodways. Since the floodway is an extremely hazardous area due to the velocity of floodwaters 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 subsection 42-90(1) above is satisfied, all new construction and substantial improvements shall comply with all applicable flood hazard reduction provisions of this division.
(3) 
Under the provisions of 44 CFR Chapter 1, Section 65.12, of the National Flood Insurance Program Regulations, 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.
[Ord. No. 1182-10, § 1, 9-28-2010; Ord. No. 1386-19, § 1, 3-25-2019]