§ 7.5-155. Provisions for flood damage reduction.

(a)

General standards. In all areas of special flood hazard and areas of future-conditions flood hazard the following provisions apply:

(1)

New construction and substantial improvements of structures (residential or nonresidential), including manufactured homes, shall not be allowed within the limits of the future-conditions floodplain, unless all requirements of subsections 7.5-154(c), (d) and (e) have been met, except for previously platted lots in subdivisions as of December 31, 2014, which meet the minimum FEMA building requirements or the requirements of a flood study approved by the city engineer prior to the effective date of this article;

(2)

New construction and substantial improvements shall be anchored to prevent flotation, collapse and lateral movement of the structure;

(3)

New construction and substantial improvements shall be constructed with materials and utility equipment resistant to flood damage;

(4)

New construction and substantial improvements shall be constructed by methods and practices that minimize flood damage;

(5)

Elevated buildings. All new construction and substantial improvements 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 or 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 licensed professional engineer or architect to meet or exceed the following minimum criteria:

1.

Provide a minimum of two (2) openings having a total net area of not less than one (1) square inch for every square foot of enclosed area subject to flooding;

2.

The bottom of all openings shall be no higher than one (1) foot above grade; and

3.

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 finished or partitioned 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 three (3) feet above the base flood elevation or one (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 and 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)

All proposed development shall include adequate drainage and stormwater management facilities per the requirements of City of Cartersville to reduce exposure to flood hazards;

(9)

New and replacement water supply systems shall be designed to minimize or eliminate infiltration of floodwaters into the system;

(10)

New and replacement sanitary sewage systems shall be designed to minimize or eliminate infiltration of floodwaters into the systems and discharges from the systems into floodwaters;

(11)

On-site waste disposal systems shall be located and constructed to avoid impairment to, or contamination from, such systems during flooding;

(12)

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;

(13)

Any alteration, repair, reconstruction or improvement to a structure which is not compliant with the provisions of this article, shall be undertaken only if the nonconformity is not furthered, extended or replaced;

(14)

If the proposed development is located in multiple flood zones, or multiple base flood elevations cross the proposed site, the higher or more restrictive base flood elevation or future condition elevation and development standards shall take precedence;

(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 article; and

(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.

(b)

Building standards for structures and buildings within the future-conditions floodplain.

(1)

Residential buildings.

a.

New construction. New construction of principal residential structures shall not be allowed within the limits of the future-conditions floodplain unless all requirements of subsections 7.5-154(c), (d) and (e) have been met. If all of the requirements of subsections 7.5-154(c), (d) and (e) have been met, all new construction shall have the lowest floor, including basement, elevated no lower than three (3) feet above the base flood elevation or one (1) foot above the future-conditions flood elevation, whichever is higher. Should solid foundation perimeter walls be used to elevate the structure, openings sufficient to automatically equalize the hydrostatic flood forces on exterior walls shall be provided in accordance with standards of subsection 7.55-155(a)(5).

b.

Substantial improvements. Substantial improvement of any principal residential structure shall not be allowed within the limits of the future-conditions, floodplain unless all requirements of subsections 7.5-154(c), (d) and (e) have been met. If all of the requirements of subsections 7.5-154(c), (d) and (e) have been met, all substantial improvements shall have the lowest floor, including basement, elevated no lower than three (3) feet above the base flood elevation or one (1) foot above the future-conditions flood elevation, whichever is higher. Should solid foundation perimeter walls be used to elevate a structure, openings sufficient to automatically equalize the hydrostatic flood forces on exterior walls shall be provided in accordance with standards of subsection 7.5-155(a)(5)a.

(2)

Nonresidential buildings.

a.

New construction. New construction of principal nonresidential structures shall not be allowed within the limits of the future-conditions floodplain unless all requirements of subsections 7.5-154(c), (d) and (e) have been met. If all of the requirements of subsections 7.5-154(c), (d) and (e) have been met, all new construction shall have the lowest floor, including basement, elevated no lower than one (1) foot above the base flood elevation or at least as high as the future-conditions flood elevation, whichever is higher. Should solid foundation perimeter walls be used to elevate the structure, openings sufficient to automatically equalize the hydrostatic flood forces on exterior walls shall be provided in accordance with standards of subsection 7.5-155(a)(5)a. New construction that has met all of the requirements of subsections 7.5-154(c), (d) and (e) may be floodproofed in lieu of elevation. The structure, together with attendant utility and sanitary facilities, must be designed to be watertight to one (1) foot above the base flood elevation, or at least as high as the future-conditions flood elevation, whichever is higher, with walls substantially impermeable to the passage of water and structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A licensed professional engineer or architect shall certify that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions above, and shall provide such certification to the ordinance administrator using the FEMA floodproofing certificate along with the design and operation/maintenance plan.

b.

Substantial improvements. Substantial improvement of principal non-residential structures shall not be allowed within the limits of the future-conditions floodplain unless all requirements of subsections 7.5-154(c), (d) and (e) have been met. If all the requirements of subsections 7.5-154(c), (d) and (e) have been met, all substantial improvement shall have the lowest floor, including basement, elevated to no lower than one (1) foot above the base flood elevation for at least as high as the future-conditions flood elevation, whichever is higher. Should solid foundation perimeter walls be used to elevate the structure, openings sufficient to automatically equalize the hydrostatic flood forces on exterior walls shall be provided in accordance with subsection 7.5-155(a)(5)a. Substantial improvements that have met all of the requirements of subsections 7.5-154(c), (d) and (e) may be floodproofed in lieu of elevation. The structure, together with attendant utility and sanitary facilities, must be designed to be watertight to one (1) foot above the base flood elevation, or at least as high as the future-conditions flood elevation, whichever is higher, with walls substantially impermeable to the passage of water and structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A licensed professional engineer or architect shall certify that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions above, and shall provide such certification to the ordinance administrator using the FEMA floodproofing certificate along with the design and operation/maintenance plan.

(3)

Accessory structures and facilities. Accessory structures and facilities (i.e., barns, sheds, gazebos, detached garages, recreational facilities and other similar non-habitable structures and facilities) which meet the requirements of subsections 7.5-154(c), (d) and (e) and are permitted to be located within the limits of the future-conditions floodplain shall be constructed of flood-resistant materials and designed to provide adequate flood openings in accordance with subsection 7.55-155(a)(5)a, and be anchored to prevent flotation, collapse and lateral movement of the structure.

(4)

Standards for recreational vehicles. All recreational vehicles placed on sites must either:

a.

Be on the site for fewer than one hundred eighty (180) consecutive days and be fully licensed and ready for highway use (a recreational vehicle is ready for highway use if it is licensed, on its wheels or jacking system, attached to the site only by quick-disconnect type utilities and security devices, and has no permanently attached structures or additions); or

b.

Meet all the requirements for residential buildings—substantial improvements (subsection 7.5-155(b)(1)), including the anchoring and elevation requirements.

(5)

Standards for manufactured homes.

a.

New manufactured homes shall not be allowed to be placed within the limits of the future-conditions floodplain unless all requirements of subsections 7.5-154(c), (d) and (e) have been met. If all of the requirements of subsections 7.5-154(c), (d) and (e) have been met, all new construction and substantial improvement shall have the lowest floor, including basement, elevated no lower than three (3) feet above the base flood elevation or one (1) foot above the future-conditions flood elevation, whichever is higher. Should solid foundation perimeter walls be used to elevate the structure, openings sufficient to automatically equalize the hydrostatic flood forces on exterior walls shall be provided in accordance with standards of subsection 7.55-155(a)(5)a.

b.

Manufactured homes placed and/or substantially improved in an existing manufactured home park or subdivision shall be elevated so that either:

1.

The lowest floor of the manufactured home is elevated no lower than three (3) feet above the level of the base flood elevation, or one (1) foot above the future-conditions flood elevation, whichever is higher; or

2.

The manufactured home chassis is elevated and supported by reinforced piers (or other foundation elements of at least an equivalent strength) of no less than thirty-six (36) inches in height above grade.

c.

All manufactured homes must be securely anchored to an adequately anchored foundation system to resist flotation, collapse and lateral movement in accordance with standards of section 7.5-155.

(c)

Building standards for structures and buildings authorized adjacent to the future-conditions floodplain.

(1)

Residential buildings. For new construction and substantial improvement of any principal residential building or manufactured home, the elevation of the lowest floor, including basement and access to the building, shall be at least three (3) feet above the base flood elevation or one (1) foot above the future-conditions flood elevation, whichever is higher. Should solid foundation perimeter walls be used to elevate the structure, openings sufficient to automatically equalize the hydrostatic flood forces on exterior walls shall be provided in accordance with standards of subsection 7.5-155(a)(5)a.

(2)

Non-residential buildings. For new construction and substantial improvement of any principal non-residential building, the elevation of the lowest floor, including basement and access to the building, shall be at least one (1) foot above the level of the base flood elevation or at least as high as the future-conditions flood elevation, whichever is higher. Should solid foundation perimeter walls be used to elevate the structure, openings sufficient to automatically equalize the hydrostatic flood forces on exterior walls shall be provided in accordance with standards of subsection 7.5-155(a)(5)a. Non-residential buildings may be floodproofed in lieu of elevation. The structure, together with attendant utility and sanitary facilities, must be designed to be watertight to one (1) foot above the base flood elevation, or at least as high as the future-conditions flood elevation, whichever is higher, with walls substantially impermeable to the passage of water and structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A licensed professional engineer or architect shall certify that the design and methods of construction are in accordance with accepted standards of practice for meeting the provisions above, and shall provide such certification to the ordinance administrator using the FEMA floodproofing certificate along with the design and operation/maintenance plan.

(d)

Building standards for residential single-lot developments on streams without established base flood elevations and floodway (A-Zones). For a residential single-lot development not part of a subdivision that has areas of special flood hazard, where streams exist but no base flood data have been provided (A-Zones), the ordinance administrator shall review and reasonably utilize any available scientific or historic flood elevation data, base flood elevation and floodway data, or future-conditions flood elevation data available from a federal, state, local or other source, in order to administer the provisions and standards of this article.

If data are not available from any of these sources, the following provisions shall apply:

(1)

No encroachments, including structures or fill material, shall be located within an area equal to twice the width of the stream or fifty (50) feet from the top of the bank of the stream, whichever is greater.

(2)

In special flood hazard areas without base flood or future-conditions flood elevation data, new construction and substantial improvements shall have the lowest floor of the lowest enclosed area (including basement) elevated no less than three (3) feet above the highest adjacent grade at the building site. Flood openings sufficient to facilitate automatic equalization of hydrostatic flood forces shall be provided for flood-prone enclosures in accordance with subsection 7.5-155(a)(5)a.

(e)

Building standards for areas of shallow flooding (AO-Zones). Areas of special flood hazard may include designated "AO" shallow flooding areas. These areas have base flood depths of one (1) to three (3) feet above ground, with no clearly defined channel. In these areas the following provisions apply:

(1)

All new construction and substantial improvements of residential and nonresidential structures shall have the lowest floor, including basement, elevated to no lower than one (1) foot above the flood depth number in feet specified on the Flood Insurance Rate Map (FIRM), above the highest adjacent grade. If no flood depth number is specified, the lowest floor, including basement, shall be elevated at least three (3) feet above the highest adjacent grade. Flood openings sufficient to facilitate automatic equalization of hydrostatic flood forces shall be provided in accordance with standards of subsection 7.5-155(a)(5)a;

(2)

New construction and substantial improvement of a nonresidential structure may be floodproofed in lieu of elevation. The structure, together with attendant utility and sanitary facilities, must be designed to be watertight to the specified FIRM flood level plus one (1) foot above the highest adjacent grade, with walls substantially impermeable to the passage of water, and structural components having the capability of resisting hydrostatic and hydrodynamic loads and the effect of buoyancy. A licensed professional engineer or architect shall certify that the design and methods of construction are in accordance with accepted standards of practice, and shall provide such certification to the ordinance administrator using the FEMA floodproofing certificate along with the design and operation/maintenance plan; and

(3)

Drainage paths shall be provided to guide floodwater around and away from any proposed structure.

(f)

Standards for subdivisions of land.

(1)

All subdivision proposals shall identify the areas of special flood hazard and areas of future-conditions flood hazard therein and provide base flood elevation data and future-conditions flood elevation data;

(2)

All residential lots in a subdivision proposal shall have sufficient buildable area outside of the future-conditions floodplain, such that encroachments into the future-conditions floodplain for residential structures will not be required; and

(3)

All subdivision plans will provide the elevations of proposed structures in accordance with subsection 7.5-153(b)(2).

(Ord. No. 04-15, § 1, 3-5-15; Ord. No. 26-18, § 1, 10-4-18)