§ 4.24. Floodplain management.
4.24.1 Purpose. It is the purpose of this section to minimize public and private losses due to flood conditions in specific areas by provisions designed to promote the public health, safety and general welfare and to:
A.
Restrict or prohibit uses which are dangerous to health, safety and property due to water or erosion hazards, or which result in damaging increases in erosion or in flood heights or velocities;
B.
Require that uses vulnerable to floods, including facilities which serve such uses, be protected against flood damage at the time of initial construction;
C.
Control the alteration of natural floodplains, stream channels, and natural protective barriers which are involved in the accommodation of flood waters;
D.
Control filling, grading, dredging and other development which may increase erosion or flood damage;
E.
Prevent or regulate the construction of flood barriers which will unnaturally divert flood waters or which may increase flood hazards to other lands; and
F.
Adopt and comply with the requirements of the Flood Disaster Protection Act of 1973 (Pub. L. 93-234, December 31, 1979) and section 60.2 (h), 60.3 (d) and 65.5 of the National Flood Insurance Program (24 CFR 1909, etc.) thereby assuring that the unincorporated areas of Fulton County and its citizens shall continue to participate in the benefits of the program and not be subject to the prohibitions contained in section 202 (a) of the 1973 act as amended.
4.24.2 Objectives. The objectives of this section are:
A.
To protect human life and health;
B.
To minimize expenditure of public money for costly flood control projects;
C.
To minimize the need for rescue and relief efforts associated with flooding, generally undertaken at the expense of the general public;
D.
To minimize prolonged business interruptions;
E.
To minimize damage to public facilities and utilities such as water and gas mains, electric, telephone and sewer lines, street and bridges located in floodplains;
F.
To help maintain a stable tax base by providing for the sound use and development of flood prone areas in such a manner as to minimize flood blight areas; and
G.
To ensure that potential home buyers are notified that property is in a flood area.
4.24.3 Jurisdiction. This section shall apply to all the unincorporated areas of Fulton County which contain special flood hazard or flood prone areas.
4.24.4 Flood areas established.
A.
Special flood hazard area shall be designated on the "floodway boundary and floodway maps" (FBFM), the "flood insurance rate maps" (FIRM), and the "flood insurance study" (FIS) prepared and revised by the Federal Emergency Management Agency (FEMA) effective June 22, 1998. As defined by FEMA, special flood hazard areas (SFHA) are classified as numbered or unnumbered zones A, AE, (formerly A1-A30), AO, and AH which are available for review on maps in the Department of Environment and Community Development or the Department of Public Works. The accompanying maps and other supporting data and any revision are hereby adopted by reference, declared to be a part of this resolution, and shall have the same force and effect as if fully set forth in this resolution. SFHA shall be identified as follows: (Amended 2/7/01)
1.
Fifty lots or five acres space or more. When FEMA has not produced water surface elevations data and the proposed development is more than 50 lots or five acres, whichever is the lesser, base flood elevation data determined in studies by the U.S. Corps of Engineers or other reputable reports based on competent engineering studies prepared by a current state-registered professional engineer and accepted by the department of public works shall be adopted by reference and declared to be a part of this section.
2.
Fewer than 50 lots or five acres. When FEMA has not produced water surface elevation data and the proposed development is not fewer than 50 lots or five acres, whichever is the lesser, then the base flood elevation data may be determined by the best information available.
B.
Regulatory floodway area shall be designated on the "flood boundary and floodway map" and the "flood insurance study" as revised by FEMA from time to time. It is the channel of a river or other watercourse and the adjacent land areas that must be reserved in order to discharge the base flood without cumulatively increasing the water surface elevation more than one foot.
C.
Flood prone area shall be designated on the "flood insurance rate map." Flood prone areas shall be those areas classified as areas of moderate and minimal flood hazards, shown thereon as "Zone X" (formerly Zone B). (Amended 6/3/98)
4.24.5 Use regulations. (Amended 04/05/06) Notwithstanding the uses permitted by the zoning district applying to the property, the following shall be prohibited in the Special Flood Hazard Area (100 year IRF): buildings and structures; filling; and compensatory flood storage for placement of either fill or for construction of a structure in the floodplain with exception to exempted uses as specified in Section 4.24.5.A. 1-8:
Floodplain designation shall be based on data generated by FEMA, Fulton County flood studies, or data from engineering flood studies prepared by a state-registered professional engineer and accepted by Fulton County (whichever is most representative of the current floodplain). Flood studies shall be approved contingent upon acceptance by FEMA.
Construction (which is consistent with the exemption provisions of this resolution) shall be allowed within floodways only if it is directed towards improving the capacity or flow characteristics of the flood waters or crossing, relocating or altering the floodway channel itself. All such construction must be in conformance with the provisions of the Fulton County Zoning Resolution and the national Flood Insurance Program.
A.
Special Flood Hazard-Flood Prone Permitted Uses. The following uses are permitted in Special Flood Hazard and Flood Prone Areas.
1.
Agricultural, including forestry and livestock raising, requiring no structure. Agriculture and forestry access roads are permitted provided they are constructed in conformance with the development standards of the regulations.
2.
Dams, provided that they are constructed in accordance with the requirement of this section, the Department of Public Works, the U.S.D.A. Soil and Conservation Service and when applicable, meet the specifications of The U.S. Army Corps of Engineers and/or the Georgia Department of Natural Resources.
3.
Fences having sufficient open area to permit the free flow of water and/or debris.
4.
Identification, regulatory and warning signs.
5.
Public and private parks and recreational areas including boat ramps and docks and other functionally dependent uses not including any temporary or permanent buildings, provided; such use is approved by the Department of Environment and Community Development, if applicable, the U.S. Army Corps of Engineers.
6.
Parking.
7.
Utility lines, pipelines, sewers, roads and stream crossings (if no other means of access is available), and similar facilities, provided they are constructed in such a manner as to permit the free flow of flood waters.
4.24.6 Permit required. A land disturbance permit or grading permit shall be required prior to the commencement of any improvement, including grading and filling, within the special flood hazard or flood prone areas. (Amended 11/3/93)
A.
Activities on lots within existing development. In developments that require only a building permit on a developed lot, portions of which are subject to flooding, the Director of the Department of Environment and Community Development shall review the application and issue the permit as part of the building permit. The flood elevation study as required by paragraph 4(a)(1) above may be waived by the Department of Public Works provided: (Amended 2/7/01)
1.
A licensed surveyor submits base flood elevation data based on the best information available.
2.
That the base flood elevation data is to be used only to establish the lowest floor elevation of a structure.
B.
Activities requiring land disturbance permit. In developments that require a land disturbance permit as provided in the "Erosion and Sedimentation Ordinance of 1978" [See Code ch. 26, art. II], the Department of Environment and Community Development shall review the application and issue the permit as part of the land disturbance permit. (Amended 11/3/93, 2/7/01)
C.
Other activities. In all other developments that involve change, modification, or alteration to a flood area, except such activities as plowing, tilling, seeding, planting, or any other agricultural or landscaping pursuit which does not result in change to the cross sectional area of the floodplain nor a significant or hazardous change in the flow characteristics, the developer shall be required to obtain the applicable permit prior to the commencement of any construction within the floodplain.
4.24.7 Permit procedure. (Amended 11/3/93)
A.
Application. Application for a permit shall be made to the Department of Environment and Community Development as indicated under permit required above. If the proposed development requires a land disturbance permit or is of such a nature as to require review and approval by the Department of Environment and Community Development, or any other appropriate agencies, the applicant shall be so advised. Such review may require additional data and/or plans to be furnished by the applicant to assure compliance with all applicable regulations. (Amended 2/7/01)
B.
Certification. The Director of the Department of Environment and Community Development shall inform an applicant of the requirements that "as-built" lowest floor elevation certificates be obtained prior to approval of a certificate of occupancy for any structure built in or immediately adjacent to a special flood hazard area. Certificates of elevation:
1.
Shall be prepared by a professional engineer or surveyor licensed by the State of Georgia.
2.
Shall be maintained in a file in the offices of the Department of Environment and Community Development and the Department of Public Works. (Amended 2/7/01)
4.24.8 Plans and studies required. Wherever it is necessary to determine that the proposed use conforms to the requirements of this section, the Department of Environment and Community Development shall require the applicant to furnish complete and sufficient plans, specifications, hydrological and engineering studies or data. Depending on the size or nature of the proposed use, any or all of the following may be required: (Amended 11/3/93, 6/3/98, 2/7/01)
A.
Grading, replanting and drainage plans;
B.
Proposed temporary and permanent drainage and sedimentation control structures and facilities;
C.
Complete hydrologic and hydraulic analysis, prepared by a professional engineer registered in the State of Georgia, establishing the 100-year base flood elevations and horizontal flood plain limits.
D.
A determination of the channel cross-section area required to carry the affected stream during the base flood;
E.
Complete hydrologic studies to evaluate the total effects a development under review may have upon affected drainage facilities and systems;
F.
The Department of Environment and Community Development may require the applicant to furnish a written agreement to limit use and development in accord with the approved plan and specifications. (Amended 2/7/01)
4.24.9 General development provisions and standards. (Amended 11/3/93)
A.
Relocation and realignment. Within a special flood hazard or flood prone area any relocation or realignment of river and stream channels shall be prohibited if it would reduce the floodway capacity with respect to the base flood elevation, or significantly alter water flow characteristics so as to create a hazard.
B.
Nonconforming uses. Except as restricted or exempted below, existing nonconforming uses within a special flood hazard or flood prone area may be maintained or repaired; modified, altered or repaired to incorporate floodproofing measures; improved to comply with existing state or local health, sanitary or safety code specifications which are solely necessary to assure safe living conditions.
1.
Restrictions.
a.
The cost of such improvement shall not equal or exceed 50 percent of the market value of the structure either, (i) before the improvement is started or (ii) if the structure has been damaged, and is being restored, before the damage occurred.
b.
Such nonconforming use shall not be expanded.
2.
Exemption. Any alteration of a structure listed on the National Register of Historic Places or a state inventory of historic places.
C.
Structures elevated above flood hazard or flood prone areas. No new structure shall be approved or constructed so as to extend over a special flood hazard or flood prone area, whether it be a cantilever design or supported by structural elements located within the floodplain.
D.
Structures adjacent to flood hazard or flood prone areas. For any proposed new structure adjacent to a special flood hazard or flood prone area the ground surface shall be at least three feet above the base flood elevation. Further, when a filled building site is required, the ground surface at the face of the wall shall be at least ten feet distant from the base floodplain. See paragraph 65.5 of the National Flood Insurance Program as amended.
E.
The lowest minimum floor elevation. The lowest floor elevation, as described in FEMA's elevation certificate on page 5 and 6, shall be at least three feet above the base flood elevation and meet the requirements of 4.24.9.G. (Amended 4/5/95)
F.
Removing flood hazard or flood prone areas. Lands may be removed from a special flood hazard area or flood prone area by raising the elevation of such land above the base flood elevation, provided the raising of such land is accomplished in accordance with the requirements of this resolution. Refer to FEMA National Flood Insurance Program Regulation 44 CFR 65 for procedures to amend the FIRM, FHBM, or FIS. The developer/property owner shall prepare all plans and engineering studies and pay any fees necessary to obtain a letter of map revision for their development. (Added 4/5/95)
G.
Residential lots. In districts which permit residential use, development is prohibited in special flood hazard areas. Fulton County may allow such development provided: (Amended 4/5/95)
1.
Not less than 70 percent of the buildable land area lies above the base flood elevation, a minimum of one foot, and/or
2.
Not less than 50 percent of the minimum lot area, as established by the applicable zoning district, shall be above the base flood elevation.
H.
Utilities. The location, design, elevation, and construction of all public utilities and facilities, such as sewer, gas, electrical, on-site waste disposal systems, water systems and streets shall be in such a manner as to minimize or eliminate damage by flooding.
I.
Drainage structures. All drainage structures and facilities located within special flood hazard or flood prone areas shall be constructed in accordance with Fulton County Standards and Specifications. They shall be maintained by the owner in a sanitary, fully functional and operable state so that the flood carrying capacity of the watercourse is preserved.
J.
Erosion and sediment control. Provision shall be made for the adequate control of erosion and sedimentation.
K.
Riverine considerations. Fulton County shall notify, in riverine situations, adjacent communities and the Georgia State Coordinating Office prior to any alteration or relocation of a watercourse.
L.
Watercourse alteration or relocation. Fulton County, prior to approval of a permit to alter or relocate a portion of any watercourse shall require an agreement indemnifying Fulton County from all liability arising from the construction pursuant to said permit and providing for the continued maintenance to assure the flood carrying capacity within the altered or relocated water course.
4.24.10 Development within flood prone areas.
A.
Development limitations. Within flood prone areas, no construction including grading and filling shall be allowed that would:
1.
Raise the base flood elevation beyond the boundaries of the ownership of the property being developed. Submittal of this certification and the supporting studies by a professional engineer are required.
2.
Reduce the flood storage capacity. Fill placed within the floodplain must be compensated. All cut areas must drain by gravity to the main watercourse. Certification by a professional engineer and an "as-built" topographical map superimposed on the original topography are required.
3.
Impede the movement of flood waters. Applies to any obstruction placed within the floodplain, i.e., fill, but in particular, roads, driveways, bridges and culverts. All such encroachments shall be designed and submitted by a professional engineer and shall provide:
a.
That there shall be no reduction in the flood carrying capacity of the watercourse.
b.
A certification together with supportive data.
c.
Sufficient opening provided for the passage of the flood waters so as to prevent or greatly reduce the hazard of debris or trash blocking the flood's flow.
4.
Changes the flow characteristics of the flood waters as they pass the boundaries of the developed property. Requires certification by a professional engineer along with all supportive studies.
5.
Create hazardous or erosion producing velocities. Requires certification by a professional engineer along with supportive studies.
B.
Stormwater management structures. Detention ponds, lakes and similar impoundment structures may be constructed within a flood prone area provided they do not violate the restrictions enumerated under paragraph 10(a) above. Provided further that any such detention pond, lake or similar impoundment structure shall provide adequate discharge control and sufficient storage capacity to assure that the rate of runoff calculated for the proposed development including that drainage increased or diverted by reason of the development shall not exceed that calculated for the property in its natural state in the event of the 100-year storm.
C.
Studies and plans required. A hydrologic analysis shall be required to be submitted to the Department of Environment and Community Development with each application for a land disturbance permit for property containing a flood prone area. Any or all of the other plans or studies referred to in paragraph 4.24.8 above may be required. Such studies shall take cognizance of existing conditions which affect the flow of water on adjacent properties and also such future conditions as can reasonably be expected to occur in the drainage basin. Such reports shall meet the requirements of the Department of Environment and Community Development. (Amended 11/3/93, 6/3/98, 2/7/01)
D.
Revision criteria. Each application for a land disturbance permit for property containing a flood prone area shall also submit therewith documented results of hydrology and hydraulic analysis prepared by a registered professional engineer demonstrating that any area defined on the FIRM or FBFM as moderate or minimal flood hazard (Zone X) is not actually a SHFA. Such results and analysis shall demonstrate that none of the following criteria is met in any flood prone area(s) on the site: (Added 6/3/98)
(1)
The flood prone area(s) is subject to a one percent (1%) annual chance of flooding with average channel depths greater than one foot or;
(2)
The flood prone area(s) has a contributing drainage area greater than one square mile or;
(3)
The flood prone area(s) has hazardous velocities in the channel and/or overbank areas greater than 3.5 feet per second. (The county may accept velocities of up to 5 feet per second depending upon the results of a soil study by the engineer).
In the event that any of the above criteria is met, the applicant shall submit to the Department of Environment and Community Development the relevant data for a Letter of Map Revision and the appropriate fees required by FEMA. The Fulton County Department of Public Works shall then submit the relevant data, letter of map revision and accompanying fees to FEMA for a determination of whether a map revision is warranted. In the event of such a map revision reclassifying an area as an SHFA, development within the affected area(s) shall comply with section 4.24.12 of this article. (Amended 2/7/01)
4.24.11 Development with unstudied special flood hazard areas. Development and revisions criteria in the unstudied special hazard areas shall be the same as in the flood prone areas, subsection 4.24.10. (Amended 6/3/98)
4.24.12 Development within studied special flood hazard areas.
A.
Development limitations. No construction shall be allowed within the studied special flood hazard areas that would:
1.
Raise the base flood elevation. Submittal of this certification and the supporting studies by a professional engineer are required.
2.
Reduce the flood storage capacity. Fill placed within the floodplain must be compensated. All cut areas must drain by gravity to the main watercourse. Certification by a professional engineer and an "as-built" topography map superimposed on the original topography are required.
3.
Impede the movement of flood waters. Applies to any obstruction placed within the floodplain but in particular, roads, bridges, driveways and culverts. All such encroachments shall be designed by a professional engineer and shall provide:
a.
That there shall be no reduction in the flood carrying capacity of the watercourse.
b.
A certification together with supportive data.
c.
Sufficient opening provided for the passage of the flood waters so as to prevent or greatly reduce the hazard of debris or trash blocking the flow of the flood.
4.
Change the flow characteristics of the flood waters. Requires certification by a professional engineer along with all supportive studies.
5.
Create hazardous or erosion producing velocities. Requires certification by a professional engineer along with supportive studies.
B.
Increase base flood elevation. The department of public works may from time to time, request a review and determination from the floodplain management administrator to permit an increase in the base flood elevation. Such increased elevation shall not exceed that depth shown in the Flood Insurance Study, Table 2, Base Flood Water Surface Elevation with Floodway Column. (Amended 4/5/95)
1.
This increase may be granted when:
a.
The development is a proposed public road, bridge and/or culvert, public utility poles, towers, pipelines, sewers and similar facilities.
b.
The development is a private lot, bridge/culvert, private utility poles, towers, pipelines, sewers or other similar facilities.
2.
A professional engineer must submit a certification along with supportive documentation that the increase does not extend beyond the boundaries of the property upon which the improvement is proposed and shall not cause any appreciable expansion of flooding, siltation, erosion or inundation hazards. (Amended 11/3/93)
3.
A developer shall apply to the Floodplain Management Administrator of Fulton County for review and approval of an application for a letter of map revision to FEMA. (Added 4/5/95)
4.
The floodplain management administrator may apply for a conditional FIRM revision to FEMA prior to permitting encroachment into a special flood hazard area. Refer to the National Flood Insurance Program Regulations 44 CFR, Part 65.12 for FEMA requirements. (Added 4/5/95)
4.24.13 Floodway alteration.
A.
Construction within regulatory floodway. When construction is proposed within the regulatory floodway such as flood control projects, stream channelization, stream relocation, construction of new dams, reservoirs, artificial canals, private levees or flood protection systems which would result in a change in the base flood elevations as shown on the flood insurance rate maps (FIRM), the following shall be required:
1.
Complete plans, data, studies and documentation for the proposed construction shall be submitted to the Department of Public Works.
2.
If the Department of Public Works determines that the project is feasible and acceptable, then the department shall submit the project to FEMA in compliance with the provisions of the National Flood Insurance Program, paragraph 65.5 as amended from time to time.
Note: Fulton County may require a fee for review of such proposals.
4.24.14 Mobile homes. All mobile homes located within the 100-year floodplain must adhere to all applicable regulations stated elsewhere in this resolution as well as the following:
A.
Anchoring. All mobile homes should be anchored to resist flotation, collapse or lateral movement, by providing over-the-top and frame ties to ground anchors. Specific requirements shall be that:
1.
Over-the-top ties be provided at each of the four corners of the mobile home, with two additional ties per side at intermediate locations. Mobile homes which are less than 50 feet long must have one additional tie per side;
2.
Frame ties be provided at each corner of the home with five additional ties per side at intermediate points. Mobile homes which are less than 50 feet long require four additional ties per side;
3.
All components of the anchoring system must be capable of carrying a force of 4,800 pounds; and
4.
Any additions to the mobile home must be similarly anchored.
B.
General requirements. All mobile homes are required to have:
1.
Lots that are elevated on compacted fill in accordance with paragraph 4.24.9(D).
2.
Adequate surface drainage and access for a hauler.
4.24.15 Subdivision plats. Hereinafter, proposed preliminary and final subdivision plats for property located contiguous to or within flood prone or special flood hazard areas shall not be approved except in accordance with the following requirements: (Amended 4/5/95)
A.
Each plat shall contain a notation clearly stating the water surface elevation of the base flood in relation to mean sea level as approved and accepted by the Department of Public Works. Any lands below this elevation shall be designated on the plat by a heavy line, depicting the base flood elevation at that point.
B.
No lot shall be approved which has less than the minimum lot area as established by the applicable zoning district regulations and 4.24.9.G above the base flood elevation.
C.
Preliminary and final subdivision plats that were approved prior to the enactment of this section are exempt from the requirements of 4.24.9.D and 4.24.15.B above, and building permits shall be issued accordingly.
D.
No final subdivision plat shall be approved by the county where development has altered the special flood hazard area unless the county has first received a letter of map amendment, letter of map revision or notice of conditional FIRM revision from FEMA as stipulated in the National Flood Insurance Program Regulations 44 CFR 65. (Added 4/5/95)
4.24.16 Abrogation and greater restrictions. This section is not intended to repeal, abrogate, or impair any existing easements, covenants, or deed restrictions. Where this section and another section of this resolution conflict or overlap, however, whichever imposes the more stringent restrictions shall prevail.
4.24.17 Interpretation. In the interpretation and application of this section, all provisions shall be:
A.
Considered as minimum requirements;
B.
Liberally construed in favor of the governing body;
C.
Deemed neither to limit nor repeal any other powers granted under state statutes.
4.24.18 Warning and disclaimer of liability. The degree of flood protection required by this section is considered reasonable for regulatory purposes and is based on scientific and engineering considerations. Larger floods can and will occur on rare occasions.
Flood heights may be increased by manmade or natural causes. This section shall not create liability on the part of Fulton County or by any official or employee thereof for any flood damages that result from reliance on this ordinance or any administrative decision lawfully made thereunder.
4.24.19 Compliance. No structure or land shall hereafter be located, extended, converted, or structurally altered without full compliance with the terms of this section and other applicable regulations.
4.24.20 Appeal. (Deleted 3/4/92, See article XXII)