Stormwater Terms & Definition


DeKalb County Code of Ordinance
The Georgia Stormwater Management Manual
The staff of the DeKalb County Stormwater Management Program.


Accidental discharge shall mean a discharge prohibited by this chapter into the DeKalb County Municipal Separate Storm Sewer System which occurs by chance and without planning or consideration prior to occurrence.

Addition (to an existing building) means any walled and roofed expansion to the perimeter of a building in which the addition is connected to a common load-bearing wall other than a firewall. Any walled and roofed addition, which is connected by a firewall or is separated by independent perimeter load-bearing walls is new construction.

Agricultural operations means those practices involving the establishment, cultivation, or harvesting of products of the field or orchard, the preparation and planting of pasture land, farm ponds, dairy operations, livestock and poultry management practices and the construction of farm buildings.

Alley means a minor way, which is used primarily for vehicular service access to the back or side of properties otherwise fronting on a street.

Appeal means a review authorized by this chapter of any final order, requirement, or decision of the planning director or the chief executive officer based on or made in the enforcement of this chapter, excluding section 14-39.

Applicant means any person who acts in the person's own behalf or as the agent of an owner of property and engages in alteration of land or vegetation in preparation for construction activity.

As-built drawings means amended site plans specifying the location, dimensions, elevations, capacities and operational capabilities of public improvements, including water, sewer, road and drainage structures and stormwater management facilities as they have been constructed.

Authorized representative shall mean:

a.     If the discharger is a business, an owner, partner, corporate officer or highest ranking employee of the business employed at the facility from which the discharge or connection was made;

b.     If the discharger is a federal, state or local government facility, a director or highest official appointed or designated to oversee the operation and performance of the activities of the government facility, or that person's designee.


Basement means a space having one-half ( 1/2) or more of its floor-to-ceiling height below the average level of adjoining ground and with a floor-to-ceiling height of not less than six and one-half (6 1/2) feet.

Best management practices (BMP's) means a wide range of stormwater management regulations, procedures, engineering designs, activities, prohibitions or practices which have been demonstrated to effectively control the quality, quantity, and erosion and sedimentation associated with stormwater consistent with the Georgia Stormwater Management Manual and the Manual for Erosion and Sedimentation Control in Georgia, as amended.

Bicycle lane means that part of a street or highway adjacent to the roadway, designated by official signs or markings for use by persons riding bicycles.

Block means a piece or parcel of land entirely surrounded by public highways or streets, other than alleys. In cases where the platting is incomplete or disconnected, the planning director may delineate the outline of the block.

Blue work order coding implies a high priority, but not an emergency situation.  Blue-coded work orders are generally addressed within 60 to 90 days.  However, priorities may be altered by newly identified red work orders.

Board or board of commissioners means the board of commissioners of DeKalb County, Georgia.

Breakaway wall means a wall that is not part of the structural support of the building and is intended through its design and construction to collapse under specific lateral loading forces without causing damage to the elevated portion of the building or the supporting system.

Buffer area means that portion of a lot set aside for open space and/or visual screening purposes, pursuant to the applicable provisions of the DeKalb County Code and all conditions of zoning, to separate different use districts, or to separate uses on one (1) property from uses on another property of the same use district or a different use district.

Buffer, stream means the portion of a lot and/or area of land immediately adjacent to the banks of streams as regulated by the land development regulations of the DeKalb County Code.

Buffer zone, state means that portion of a lot and/or area of land immediately adjacent to the banks of state waters or streams set aside for protection of water quality and aquatic habitat by Chapter 5 of Title 12 of the Official Code of Georgia, the Metropolitan River Protection Act.

Buildable area means the area of a lot remaining after all setback requirements, including buffer areas, have been met.

Builder as used in sections 14-135 and 14-136 means a person who constructs a structure or dwelling for residential occupancy by humans.

Building means any structure having a roof supported by columns or walls and intended for the shelter, housing, or enclosure of any individual, animal, process, equipment, goods, or materials of any kind.

Building permit means required written permission issued by the development director for the construction, repair, alteration, or addition to a structure.

Building setback line means the minimum horizontal distance required between the street right-of-way line and the principal building or structure on a lot or any projection thereof except the projections that are authorized exception to building setback line requirements in Chapter 27 and all conditions of zoning.


Caliper means the diameter of a tree trunk, applied only to new or replacement plantings, that is taken six (6) inches above the ground for up to and including four-inch caliper size, and twelve (12) inches above the ground for larger sizes.

Catch basins are the curbside openings that collect rainwater from streets and serves as an entry point to the storm drain system.

Channel Protection shall provide extended detention of the 1-year storm (3.36 inches) such that the volume is released over a 24-hour period to reduce bankfull flow conditions and downstream channel scour.

Capital Improvement Plan (CIP) Projects are generally larger in scale than those logged as work orders and may require significant design and/or construction resources internal or external to the County.  CIP projects are individually approved and are generally funded by specific allocations by the Board of Commissioners.

Chief executive officer means the chief executive officer of DeKalb County or designee.

Citizens Drainage Program is a program to assist homeowners in managing drainage conditions on private property since the County has no responsibility for stormwater management on private property, including ditches, creeks or easements.  Under the CDP, a property owner may request drainage pipes and/or rubble rock up to a value of $2,500 (about 50 tons of rock).  Upon approval by County drainage inspectors, the County will provide the material, but the installation and follow-up maintenance are the responsibility of the homeowner.

Collector street means a street or road designated as a collector street in the DeKalb County Thoroughfare Plan.

Comprehensive plan means the DeKalb County Comprehensive Plan, 1995-2015, adopted by the board of commissioners on June 18, 1996, as it may be amended from time to time, which divides the unincorporated areas of the county into land use categories and which constitutes the official policy of the county regarding long-term planning and use of land.

Construction means any alteration of land for the purpose of achieving its development or changed use, including particularly any preparation for, building of or erection of a structure.

Construction waste means waste building materials and rubble resulting from construction, remodeling, repair and demolition operations on pavements, houses, commercial buildings and other structures. Such waste includes, but is not limited to: asbestos containing waste, wood, tree stumps, tree tops, bricks, metal, concrete, wall board, paper, cardboard, glass, wire, plastics, and other typical construction waste products and refuse.

Cooling water shall mean water used exclusively as a cooling medium in an appliance, device or apparatus.

County means DeKalb County, Georgia, a political subdivision of the State of Georgia. When appropriate to the context, the term "county" also includes authorized officers, employees and agents thereof.

County arborist means the county official having the primary responsibilities of administration and enforcement of the tree protection ordinance.

County zoning ordinance or zoning ordinance means the zoning ordinance of DeKalb County, Georgia.

Credits, Stormwater Credit System. Credits are available for properties with detention and/or treatment facilities that either reduce the amount of stormwater discharged into the county system or treat it to a standard higher than that required by county drainage codes prior to discharge.  The credits can help qualifying properties reduce their stormwater utility fees by as much as 40 percent.

Critical root zone means an area of root space that is within a circle circumscribed around the trunk of a healthy tree using a radius of one (1) foot per inch DBH.

Crosswalk means a right-of-way within a block dedicated to public use, ten (10) feet or more in width, intended primarily for pedestrians and from which motor-propelled vehicles are excluded, and which is designed to improve or provide access to adjacent roads or lots.

Customer shall mean all persons, properties, and entities served by the utility’s acquisition, management, maintenance, extension, and improvement of the public storm water management systems and facilities and regulation of public and private stormwater systems, facilities, and activities related thereto, and persons, properties, and entities which will ultimately be served or benefited as a result of the stormwater management program.

Cut means a portion of land surface or area from which earth has been removed or will be removed by excavation; the depth below original ground surface to excavated surface. Also known as "excavation."


DBH (Diameter at breast height) means the diameter of a tree trunk measured in inches at a height of four and one-half (4 1/2) feet above the ground. If a tree splits into multiple trunks below four and one-half (4 1/2) feet, then the trunk is measured at its most narrow point beneath the split.

DNR means the Department of Natural Resources of the State of Georgia.

DeKalb County Municipal Separate Storm Sewer System shall mean a stormwater conveyance or system of stormwater conveyances which is:

a.     Owned or maintained by DeKalb County;

b.     Designed or used for collecting or conveying stormwater;

c.     Not a combined sewer;

d.     Not part of a publicly owned treatment works (POTW); and

e.     Not located within the boundaries of a city located within DeKalb County or owned or operated by any other government body.

DeKalb County Stormwater Management Program shall mean that program of activities and procedures for stormwater management as set forth in the application for the permit, as approved by the Georgia EPD, and any amendment or modification thereto.

Density factor means a unit of measurement used to prescribe the calculated required tree coverage on a site.

Detention facility means a facility that provides for storage of stormwater runoff and controlled release of this runoff during and after a flood or storm.

Developed land shall mean all property not deemed as Undeveloped Land.

Developer means any person who acts in the person's own behalf or as the agent of an owner of property and engages in alteration of land or vegetation in preparation for construction activity.

Development means all activities associated with the conversion of land or the expansion of replacement of an existing use to any new use intended for human operation, occupancy, or habitation, other than for agricultural purposes devoted strictly to the cultivation of land, dairying or animal husbandry. Such activities include, but are not limited to, land disturbance (clearing and grubbing the land of vegetation and stumps, and grading) and the construction of improvements such as, but not limited to, streets, driveways or parking area, water sewer mains, storm water drainage facilities, sidewalks or other structures permanently placed in or on the property. Where appropriate to the context, development also may be used to denote a specific subdivision or project which is a single entity or intended to be constructed as in interrelated whole, whether simultaneously or in phases.

Development director means the director of the development department of DeKalb County or designee.

Development permit means any permit that authorizes land disturbance for the use, construction thereon or alteration of any real property within the unincorporated limits of the county.

Director shall mean either the director of public works or any of that person's authorized representatives or, when a department other than the public works department is designated to enforce provisions of this chapter or any portion thereof, the director of such department or any of that person's authorized representatives.

Director, EPD means the director of the environmental protection division of the department of natural resources.

Discharge shall mean the spill, draining, dumping, deposit, seeping, disposal, placement, release or loss of any material or substance to the DeKalb County Municipal Separate Storm Sewer System.

Discharger shall mean any person who discharges to the DeKalb County Municipal Separate Storm Sewer System, either directly or indirectly, including, without limitation, the owner and occupant of the property where the discharge occurs and the person responsible for or performing the discharge. For purposes of notice, "discharger" shall include the authorized representative of such discharger.

Drainage means the removal of surface or subsurface water from a given area, either by gravity or by pumping, commonly applied herein to surface water.

Drainage easements, stormwater management of.  In legally recorded drainage easements where a storm drain or other closed stormwater management facility has been constructed and accepted by the DeKalb County Development Department, DeKalb County will maintain or repair such facility to function as designed.  In drainage ways and easements where open ditches cross private property, there is no stated or implied responsibility to provide maintenance or repair.  The County retains a right, but not a duty, to perform such maintenance and repair work.  Landscaping and aesthetic improvements within drainage easements are not the responsibility of DeKalb County.

Drainage Master Plans provide a comprehensive set of improvements on a watershed basis, these Plans are the basis for future CIP planning.

Drainage plan means a plan prepared using appropriate and commonly accepted engineering standards, which specifies the means for alteration or development of a drainage system.

Drainage structure means a device composed of a virtually nonerodible material such as concrete, steel, plastic or other such material that conveys water from one (1) place to another by intercepting the flow and carrying it to a release point for stormwater management, drainage control, or flood control purposes.

Drainage system means the surface and subsurface system for the removal of water from the land, including, but not limited to, both the natural elements of streams, marshes, swales and ponds, whether of an intermittent or continuous nature, and the manmade element which includes culverts, ditches, channels, detention facilities that comprise the storm drainage system.


Early Action Plan is part of the initial stormwater utility implementation activities to address a backlog of 2002 and 2003 priority drainage projects.

Easement shall mean an acquired legal right for the specific use of land owned by others.

Ecosystem Restoration Projects. The U.S. Army Corps of Engineers (USACE) is evaluating the need for and feasibility of ecosystem restoration projects, specifically stream restoration projects. The Roads and Drainage Division is providing in kind support services for the first two years of this program and then a $100,000 per year local match is planned for USACE studies, to leverage Federal funds for future projects.

Elevated building means a nonbasement building built to have the lowest floor elevated above ground level by means of fill, solid foundation perimeter walls, pilings, columns (posts and piers), and/or shear walls.

EPD means the Environmental Protection Division of the Department of Natural Resources.

Equivalent Residential Unit (ERU) shall mean the unit of measure which provides the basis for comparing the runoff generated by one parcel with that generated by another.  An ERU shall be the median impervious coverage of a statistical sampling of single detached dwelling lots in DeKalb County, which has been determined to be three thousand (3000) square feet of impervious area.

Erosion means the general process whereby earth is moved by flowing surface or subsurface water.

Erosion and sedimentation control plan means a plan for the control of soil erosion and sedimentation resulting from a land disturbing activity and that conforms to the requirements of the Manual for Soil Erosion and Sedimentation Control in Georgia.

Exceptional and historical trees means those trees or stands of trees which are exceptional representatives of their species in terms of size, age or unusual botanical quality, or are associated with historically notable events.

Existing manufactured home park or subdivision means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) was completed before June 6, 1974.

Expansion to an existing manufactured home park or subdivisionmeans the preparation of additional sites by the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads).

Extent of Service for stormwater utility program activities refers to the geographic areas where DeKalb County has taken responsibility for stormwater services.

Extreme Flood Protection provides peak discharge control such that the peak runoff rate for a 100-year design storm from the affected impervious area does not increase the runoff rate under undeveloped conditions at the property boundary line or at any location within a downstream drainage area equal to 10 times the area of the affected impervious area.


Federal Clean Water Act or Clean Water Act shall mean the Federal Water Pollution Control Act, as amended, presently codified at 33 U.S.C. 1251 et seq., and all regulations adopted pursuant thereto.

Federal EPA or EPA shall mean the United States Environmental Protection Agency.

Fill means a portion of land surface to which properly compacted soils have been added: the depth above the original ground.

Finished grade means the final elevation and contour of the ground after cutting or filling and conforming to the proposed design.

Flood or flooding means a general and temporary condition of partial or complete inundation of normally dry land areas from the usual and rapid accumulation or runoff of surface waters from any source.

Flood hazard boundary map (FHBM) means an official map of a community, issued by the Federal Emergency Management Agency, where the boundaries of the areas of special flood hazard have been defined as zone A.

Flood hazard map means the official county map designating the elevation and boundaries of flooding and associated floodways under base flood conditions maintained by the county, based upon the flood insurance study for the county dated January 5, 1983 or any revision thereto, the United States Corps of Engineers or other reputable reports accepted by the roads and drainage director, and based upon competent engineering studies prepared by a currently state-registered professional engineer, or the county.

Flood insurance rate map (FIRM) means an official map of a community, on which the Federal Emergency Management Agency has delineated both the areas of special flood hazard and the risk premium zones applicable to the community.

Flood insurance study is the official report provided by the Federal Emergency Management Agency. The report contains flood profiles, as well as the flood boundary floodway map and the water surface elevation of the base flood.

Floodway means 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 (1) foot.

Floor means the top surface of an enclosed area in a building (including basement), i.e., the top of slab in concrete slab construction or top of wood flooring in wood frame construction. The term does not include the floor of a garage used solely for parking vehicles.

Frontage, lot means the distance for which the front boundary line of the lot and the street line are coincident.

Functionally dependent facility means a facility which cannot be used for its intended purpose unless it is located or carried out in close proximity to water, such as a docking or port facility necessary for the loading and unloading of cargo or passengers, shipbuilding, ship repair, or seafood processing facilities. The term does not include long-term storage, manufacture, sales, or service facilities.


Georgia Environmental Protection Division (EPD) shall mean the Environmental Protection Division of the Georgia Department of Natural Resources.

Georgia Stormwater Management Manual (GSMM) is being utilized by DeKalb County to reduce both stormwater quality and quantity impacts, and protect downstream areas and receiving waters. The manual is organized into two volumes; Volume I provides guidance on the basic principles of effective urban stormwater management and, Volume II which must be used by local developers and engineers as the minimum standard for design and construction of stormwater facilities for new development and redevelopment.

Georgia Water Quality Control Act or Water Quality Control Actshall mean the Georgia Quality Control Act, as amended, presently codified at O.C.G.A. § 12-5-20 et seq., and all regulations adopted pursuant thereto.

Governing body shall mean the chief executive officer and board of commissioners of DeKalb County.

Grading means altering the shape of ground surfaces to a predetermined condition; this includes stripping, cutting, filling, stockpiling and shaping or any combination thereof and shall include the land in its cut or filled condition.

Green work order coding indicates less urgent, but chronic problems that need attention to relieve minor problems or nuisances.  These are generally routine maintenance items, such as clearing debris or sediment.  A number of green-coded work orders are addressed concurrently with the red and blue ones, as staff and resources permit.  In general, the backlog of green work orders is more than 90 days.  Newly identified and more urgent red or blue work orders may preclude the completion of green work orders of lesser importance.

Ground elevation means the original elevation of the ground surface prior to cutting or filling.

Ground water shall mean water beneath the earth's surface between saturated soil and rock.


Highest adjacent grade means the highest natural elevation of the ground surface, prior to construction, next to the proposed walls of a building.

Household hazardous waste means common everyday products that people use in and around their homes including paint, paint thinner, herbicides, and pesticides that, due to their chemical nature, can be hazardous if not properly disposed.


Illicit discharge/connection shall mean a discharge or connection to the DeKalb County Municipal Separate Storm Sewer System that contains pollution or that is not composed entirely of stormwater, except such discharges which are pursuant to, and are in compliance with, a National Pollution Discharge Elimination System permit (other than the permit for discharges from the DeKalb County Municipal Separate Storm Sewer System).

Impervious surface shall mean those areas, which prevent or impede the infiltration of stormwater into the soil as it entered in natural conditions prior to development.  Common impervious surfaces include, but are not limited to, rooftops, sidewalks, walkways, patio areas, driveways, parking lots, storage areas, compacted gravel and soil surfaces, awnings and other fabric or plastic coverings.

Improvement of a stormwater facility shall include replacement of a stormwater facility, in whole or in part, with the intent of increasing the capacity or performance beyond the level of the original design and construction.  Installation of new stormwater management facilities where none existed before is included in this category.  Drainage improvements generally involve some level of engineering evaluation and design.

Incorporated Cities means the City of Atlanta in DeKalb County, Avondale Estates, Chamblee, Clarkston, Decatur, Doraville, Lithonia, Pinelake, and Stone Mountain

Intermediate regional flood (IRF) means a one-hundred-year frequency flood as defined on the flood hazard map which has a probability of occurring once every one hundred (100) years or having a one (1) percent chance of being equaled or exceeded in any given year. Also known as the base flood, or one hundred-year flood.

Intermediate regional floodplain means the land area within the floodplain within a community subject to a one (1) percent or greater chance of flooding in any given year as defined on the flood hazard map. Also known as area of special flood hazard, or one hundred-year floodplain.

Issuing authority means the planning director or designated representative who shall be responsible for administering this chapter and the governing authority certified by the environmental protection division of the department of natural resources as an issuing authority, pursuant to the Erosion and Sedimentation Act of 1975, as amended.


Land disturbance activity means any activity which may result in soil erosion from water or wind and the movement of sediments into state waters or on to lands within the state, or alteration of the site vegetative cover in any manner, including but not limited to, clearing, grubbing, stripping, dredging, excavating, transporting and filling of land.

Level of Service describes the target activities or performance criteria for each of the areas for which the County Stormwater Utility has responsibilities. Further discussed in Section 2.

Live detention means that quantity of water capable of being effectively contained by a designated facility for stormwater storage for a specified period of time.

Local street means a street used primarily for access to abutting properties in residential, industrial or other developments.

Lot means a designated parcel, tract, or area of land legally established by plat, subdivision, or as otherwise permitted by law, to be separately owned, used, developed, or built upon.

Lot, corner means a lot abutting upon two (2) or more streets at their intersection or upon two (2) parts of the same street forming an interior angle of less than one hundred thirty-five (135) degrees.

Lot, double-frontage means a lot that abuts two (2) parallel streets or that abuts two (2) streets that do not intersect at the boundaries of the lot. A double-frontage lot may also be referred to as a through lot.

Lowest floor means the lowest floor of the lowest enclosed area, including basement. An unfinished or flood-resistant enclosure, usable solely for parking of vehicles, building access or storage in an area other than a basement area is not considered a building's lowest floor; provided, that such enclosure is not built so as to render the structure in violation of the applicable nonelevation design requirements of 44 CFR 60.3.


Maintenance shall mean any action necessary to preserve stormwater conveyances in proper working condition, in order to serve the intended purposes set forth in this chapter or to prevent structural failure of such conveyances.  An example would be removal of debris or sediment that is impairing the performance of the stormwater facility

Maintenance of detention facility means preserving the enclosed walls or impounding embankments of the detention facility in good condition; ensuring structural soundness, functional adequacy and freedom from excessive sediment; removing obstructions affecting operation of outlet device(s) and rectifying any unforeseen erosion problems.

Major thoroughfare/major arterial means a street, road or highway shown as a major thoroughfare in the DeKalb County Transportation and Thoroughfare Plan.

Manufactured home means a new or used structure, transportable in one (1) or more sections, which, in the traveling mode, is eight (8) body feet or more in width or forty (40) body feet or more in length or, when erected on site, is three hundred twenty (320) or more square feet and which is built on a permanent chassis and designed to be used as a dwelling with or without a permanent foundation when connected to the required utilities and includes the plumbing, heating, air-conditioning, and electrical systems contained therein; except that such term shall include any structure which meets all the requirements of this paragraph except the size requirements and with respect to which the manufacturer voluntarily files a certification required by the secretary of housing and urban development and complies with the standards established under the National Manufactured Housing Construction and Safety Standards Act of 1974, 42 U.S.C. section 5401 et seq.

Master Account Database includes all parcels within DeKalb County (including Cities) was obtained from the Office of Property Appraisal and Assessment.  The current effective date of the database is January 10, 2003 but updates are planned for early 2004.

Mean sea level means the average height of the sea for all stages of the tide. It is used as a reference for establishing various elevations within the floodplain. For purposes of this chapter, the term is synonymous with national geodetic vertical datum (NGVD).

Metropolitan North Georgia Water Planning District (the District) is a planning entity dedicated to developing comprehensive regional and watershed-specific plans to be implemented by the local governments in the District. It is comprised of 16 counties, including Bartow, Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Fulton, Forsyth, Gwinnett, Hall, Henry, Paulding, Rockdale, and Walton. More information on the District can be found at

Minor thoroughfare/minor arterial means a street, road or highway shown as a minor thoroughfare in the DeKalb County Transportation and Thoroughfare Plan.

Multiple dwelling lot shall mean a developed lot whereon more than one attached or detached residential dwelling units are located. 

Multi-phase residential development means any development undertaken by a single developer or a group of developers acting in concert, to develop lots for sale in a residential subdivision where such land is developed pursuant to multiple preliminary or final plats and such land is contiguous or is known, designated, or advertised as a common unit or by a common name.

Multi-use trail means a recreation corridor intended for the use of non-motorized forms of transportation such as, but not limited to, walking, running, bicycles, in-line skates, as identified in a master plan for multi-use trails in DeKalb County approved by the board of commissioners.

Municipal Separate Storm Sewer (MS4) DeKalb County is part of Phase I of GAEPD’s Municipal Separate Storm Sewer System (MS4) permit program.  As such it has established a comprehensive stormwater management program (SWMP) and plan to control storm­water pollution discharges to waters of the State to the maximum extent practical and to prevent non-stormwater discharges from entering the stormwater system.  This is accomplished through such measures as structural and non-structural stormwater controls, best management practices (BMPs), regular inspections, enforcement activities, stormwater monitoring, and public education efforts. Stormwater management ordinances, erosion and sedimentation control ordinances, development regulations, and other local regulations provide the legal authority necessary to implement the stormwater management programs.


National geodetic vertical datum (NGVD), as corrected in 1929, is a vertical control used as a reference for establishing varying elevations within the floodplain.

National Pollutant Discharge Elimination System (NPDES) permit program was established under the Clean Water Act to control water pollution by regulating the discharge of pollutants into waters of the United States. The NPDES program covers several pollutant sources that are regulated by permits issued by the GAEPD. These include:

·         Municipal Wastewater Treatment Facilities

·         Sanitary Sewer Overflows (SSOs)

·         Combined Sewer Overflows (CSOs)

·         Industrial and Commercial Wastewater Discharges

·         Pretreatment Facilities

·         Concentrated Animal Feeding Operations (CAFOs)

·         Municipal Storm Sewer Discharges

·         Industrial Stormwater

·         Stormwater Permits for Construction Areas

Natural ground surface means the ground surface in its original state before any grading excavation or filling.

Nephelometric turbidity units (NTU's) means numerical units of measure based upon photometric analytical techniques for measuring the light scattered by finely divided particles of a substance in suspension. This technique is used to estimate the extent of turbidity in water in which colloidally dispersed chapters are present.

New construction means any structure for which the permitted date of construction commenced after adoption of this chapter.

New manufactured home park or subdivision means a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, the construction of streets, and either final site grading or the pouring of concrete pads) is completed on or after June 6, 1974.

Non-point source pollution is pollution that does not come from a single, identifiable source. Includes materials that wash from roofs, streets, yards, driveways, sidewalks and other land areas. Collectively, this is the largest source of stormwater pollution.


Open space means that portion of a lot, including yards, established pursuant to the requirements of this chapter as open space, which is open and unobstructed from ground level to the sky, with the exception of natural foliage or accessory recreational facilities or walkways, which is accessible to all persons occupying a building on the lot and is not a part of the roof of any portion of any building.

One hundred-year floodplain means land in the floodplain subject to a one (1) percent or greater statistical occurrence probability of flooding in any given year.

Other developed land shall mean, but shall not be limited to, commercial and office buildings, industrial and manufacturing buildings, storage buildings and storage areas covered with impervious surfaces, parking lots, parks, recreation properties, public and private schools and universities, research stations, hospitals and convalescent centers, airports, and agricultural uses covered by impervious surfaces.

Outfall means a flow of water from one drainage system into a larger system, or into a body of water like a wash bay, or lake.

Overbank Flood Protection shall provide peak discharge control such that the peak runoff rate for a 25-year design storm from the affected impervious area does not exceed 90 percent of the rate under undeveloped conditions.

Owner means the person in whom is vested the fee ownership, dominion or title of property, the proprietor; this term may also include a tenant, if chargeable under the lease for maintenance of the property, and any agent of the owner or tenant including a developer.


Permit shall mean the National Pollution Discharge Elimination System Permit for Discharges from the DeKalb County Municipal Separate Storm Sewer System issued by the Georgia EPD on or about June 15, 1994, or such subsequent permit or authorization for discharges from the DeKalb County Municipal Separate Storm Sewer System to waters of the state.

Person means any individual, partnership, firm, association, joint venture, public or private corporation, trust, estate, commission, board, public or private institution, utility, cooperative, state agency, municipality or other political subdivision of this state, any interstate body or any other legal entity.

Planning commission means the planning commission of DeKalb County.

Planning director means the director of the department of planning of DeKalb County or designee.

Point source pollution means pollution from a single identifiable source such as a factory or a sewage-treatment plant. Most of this pollution is highly regulated at the state and local levels.

Pollution or polluted shall mean the contamination or other alteration of any of water's physical, chemical or biological properties, including, but not limited to, change in temperature, taste, color, turbidity, or odor of such waters; or the discharge of any liquid, gaseous, solid, radioactive, or other substance into the DeKalb County Municipal Separate Storm Sewer System as will or is likely to create a nuisance or render any waters contained therein or discharged into waters of the state harmful, detrimental or injurious to the public health, safety or general welfare or to domestic, commercial, industrial, agricultural, recreational, or other legitimate beneficial uses, or to livestock, wild animals, birds, fish or other aquatic life.

Ponds, Commercial - Facilities on commercial property, or facilities in residential areas where maintenance responsibility is retained by the homeowners, are the responsibility of the property owner or designated homeowners association and may be inspected by the County.

Ponds, Residential - Detention ponds and other stormwater management facilities recorded on residential plats, and that have been accepted by the County, will be maintained and/or repaired to function as designed.

Potential purchaser means a person purchasing property in a residential subdivision or a multi-phase residential development from a developer and/or builder for occupancy as a residence or as a residence to be rented or leased to others.

Prioritization Process shall mean the process by which work orders are color coded, depending on urgency.  Red coding implies top priority to alleviate a situation that poses a threat to public health and safety (generally addressed within 30 days of their identification). Blue coding implies a high priority, but not an emergency situation, these work orders are generally addressed within 60 to 90 days. Green coded work orders are less urgent, but chronic problems that need attention to relieve minor problems or nuisances. In general, the backlog of green work orders is more than 90 days.

Private shall mean property or stormwater conveyances owned by individuals, corporations, and other organizations and not by city, county, state or federal governments.

Procedure shall mean a procedure adopted by the department to implement a regulation or regulations adopted under this chapter, or to carry out other responsibilities as may be required by this chapter or other chapters of the DeKalb County Code, or other ordinances or resolutions of DeKalb County or other agencies.

Project means the entire proposed development project regardless of the size of the area of land to be disturbed.

Protected zone means all areas of a parcel required to remain in open space, including all areas required as yard areas, buffer areas, stream buffers, state buffer zones or landscaped areas according to provisions of the DeKalb County Zoning Ordinance or by conditions of zoning or variance approval.

Public facilities shall mean the roads, water, sewer, schools, traffic control devices, and electrical service.

Public rights-of-way, stormwater management of. The County will manage stormwater along County-owned public rights-of-way and will coordinate with the Georgia Department of Transportation to address state roads and interstate highways.  Beyond the right-of-way in residential areas, the County maintenance responsibility extends 10 feet beyond any constructed conveyance that discharges on private property.  In commercial areas, the County responsibility ends at the right-of-way limit.


Reach means a longitudinal segment of a stream or river measured along specified points on the stream or river.

Recreation areas means those portions of open space designed and intended for active recreational use, such as sports fields and other play areas.

Recreational vehicle means a vehicle that is:

(1)     Built on a single chassis;

(2)     Four hundred (400) square feet or less when measured at the largest horizontal projection;

(3)     Designed to be self-propelled or permanently towable by a light duty truck; and

(4)     Designed primarily not for use as a permanent dwelling but as temporary living quarters for recreational, camping, travel, or seasonal use.

Red work order coding implies top priority to alleviate a situation that poses a threat to public health and safety, that results in a significant water quality problem or creates an obstruction of a public right-of-way (road) or drainage easement (stream).  Red work orders are generally addressed within 30 days of their identification.

Regulation shall mean any regulation, rule, development standard, or other requirement prepared by the department and adopted by the governing body pursuant to the requirements of this chapter.

Repair of a stormwater facility shall include the replacement of a stormwater facility, in whole or in part, to restore the performance to the level of the original design and construction

Residential shall have the same meaning as given in Chapter 27 except that it shall not include apartments.

Roadway drainage structure means a device such as a bridge, culvert, or ditch, composed of a virtually nonerodible material such as concrete, steel, plastic or other such material that conveys water under a roadway by intercepting the flow on one (1) side of a traveled way consisting of one (1) or more defined lanes, with or without shoulder areas, and carrying water to a release point on the other side.

Rock outcropping means a single, contiguous piece of exposed rock that has a horizontal surface area equal to or greater than two hundred (200) square feet.

Runoff means the portion of precipitation on the land that reaches the drainage system.

Runoff coefficient means the ratio of runoff to rainfall.


Sanitary sewer system shall mean the complete sanitary sewer system of DeKalb County which discharges sanitary sewerage directly or indirectly into the sewage treatment plant, including sanitary sewer pipelines, manholes and flushing inlets and appurtenances to the foregoing, but shall exclude any portion or facilities of the sewage treatment plant.

Sediment means solid material, both organic and inorganic, that is in suspension, is being transported, or has been moved from its site of origin by air, water, ice or gravity as a product of erosion.

Sedimentation means the process by which eroded material is transported and deposited by the action of water, wind, ice or gravity.

Sedimentation facility means a detention facility specifically developed for the purpose of allowing the deposit of sediment resulting from the land development process which may be constructed as part of or separately from a detention facility.

Sediment basin means a detention facility specifically developed for the purpose of allowing the deposit of sediment resulting from the land development process that may be constructed as part of or separately from a detention facility.

Seller means a builder or developer.

Service Fees shall mean the stormwater management service fees applicable to a parcel of developed land, which charge shall be used to fund the DeKalb County stormwater utility’s cost of providing stormwater management services and facilities.

Service Request, a service request is logged into the computer data base when an initial stormwater improvement need is identified by a citizen or staff member. An inspector is dispatched to evaluate County responsibility, seriousness, level of effort to repair, etc. See Section 2 for an additional discussion on this process.

Significant tree means any existing, healthy, living tree eight (8) inches DBH or greater in size.

Single dwelling lot shall mean a developed lot containing one dwelling structure with its principal use being a residential dwelling.

Site shall mean any lot, plot, parcel or tract of land.

Site plan means that plan required to acquire a development, construction or building permit which shows the means by which the applicant will conform with applicable provisions of this chapter and other applicable ordinances.

Source control: Action to prevent pollution where it originates.

Specimen tree means any tree that has been determined to meet the criteria within section 14-39 for the determination of specimen trees.

SS&WCC means the state soil and water conservation commission.

Stabilization means the process of establishing an enduring soil cover of vegetation by the installation of temporary or permanent structures for the purpose of reducing to a minimum the erosion process and the resultant transport of sediment by wind, water, ice or gravity.

Start of construction (for other than new construction or substantial improvements under the Coastal Barrier Resources Act (Pub. L. 97-348)), includes substantial improvements, and means the date the building permit was issued, provided the actual start of construction, repair, reconstruction, placement or other improvement was within one hundred eighty (180) days of the permit date. The actual start means either the first placement of permanent construction of a structure on a site, such as the pouring of slab or footings, the installation of piles, the construction of columns, or any work beyond the stage of excavation; or the placement of a manufactured home on a foundation. Permanent construction does not include land preparation, such as clearing, grading and filling; nor does it include the installation of streets and/or walkways; nor does it include excavation for a basement, footings, piers or foundations or the erection of temporary forms; nor does it include the installation on the property of accessory buildings, such as garages or sheds not occupied as dwelling units or not part of the main structure.

State means the State of Georgia.

State waters means any and all rivers, streams, creeks, branches, lakes, reservoirs, ponds, drainage systems, springs, wells, and other bodies of surface or subsurface water, natural or artificial, lying within or forming a part of the boundaries of the state, which are not entirely confined and retained completely upon the property of a single individual, partnership, or corporation except as defined in O.C.G.A. § 12-7-17.

Stormwater shall mean any type of stormwater runoff, snow melt runoff, surface or subsurface runoff or drainage.

Stormwater conveyance shall mean natural or constructed stormwater conduits, features, facilities or best management practices designed or used for the collection, conveyance or treatment of stormwater through open or closed drainage systems, including, but not limited to, pipes, ditches, depressions, swales, roads with drainage systems, highways, rights-of-way, county streets, catch basins, curbs, gutters, ditches, manmade channels, storm drains, detention ponds, retention ponds, infiltration devices, oil/water separators, sediment basins, modular pavement or other such devices.

Stormwater discharge associated with industrial activity shall mean the discharge from any stormwater conveyance which is directly related to manufacturing, processing or raw materials storage areas at an industrial facility. The term includes, but is not limited to, stormwater discharges from industrial facility yards; immediate access roads and rails lines used or traveled by carriers of raw materials, manufactured products, waste materials or by-products used or created by the facility; material handling sites; refuse sites; sites used for the storage and maintenance of material handling equipments; sites used for application or disposal of process wastewaters; sites used for residual treatment, storage, or disposal; shipping and receiving areas; manufacturing buildings; storage areas (including tank farms for raw materials, and intermediate and finished products) and areas where industrial activity has taken place in the past and significant materials remain and are exposed to stormwater.

Stormwater management shall mean the collection, conveyance, storage, treatment and disposal of stormwater in a manner to meet the objectives of this chapter and which shall include a system of vegetative or structural measures, or both, that control the increased volume and rate of stormwater and water quality impacts caused by manmade changes to the land.

Stormwater management facility means those structures and facilities that are designed for the collection, conveyance, storage, treatment and disposal of stormwater runoff into and through the drainage system.

Stormwater management system means any one or more of the various devices used in the collection, treatment, or disposition of storm, flood or surface drainage waters, including all manmade structures or natural watercourse for the conveyance or transportation of runoff, such as: detention areas, berms, swales, improved watercourses, open channels, bridges, gulches, streams, gullies, flumes, culverts, gutters, pumping stations, pipes, ditches, siphons, catch basins and street facilities; all inlets; collection, drainage or disposal lines; intercepting sewers; disposal plants; outfall sewers; all pumping, power, and other equipment and appurtenances; all extension, improvements, remodeling, additions, and alterations thereof; and any and all rights or interests in such stormwater facilities. Stormwater facilities expressly excludes any of the foregoing which exist for, or are used exclusively for the purpose of collection, treating, measuring, supplying, or distributing potable water within or as part of the county water supply and treatment system, or any of the foregoing which exist for or are used exclusively for the purpose of collecting, treating, or measuring effluent within or as part of the county sanitary sewer system.

Stormwater runoff shall mean the direct response of a land surface to precipitation and includes the surface and subsurface runoff or drainage or other concentrated flow that enters a stormwater conveyance during and following precipitation.

Stream means natural, running water flowing continuously or intermittently in a channel on or below the surface of the ground, and shall include, but not be limited to, all streams depicted on the 1995 DeKalb County Geographic Information System (GIS) map maintained by the DeKalb County GIS director. No stream shall be excluded from this definition due to its failure to be identified on the map. Field verification shall be performed to make a final determination as to the existence of a stream where a dispute exists. Such field verification shall be performed by the chief executive officer.

Street, private means an access way similar to and having the same function as a public street, providing access to more than one (1) property but held in private ownership. Private streets, when authorized, shall be developed in accordance with the specifications for public streets established in Division 3, Part B of this chapter.

Street, public means any right-of-way set aside for public travel deeded to the county and any right-of-way that has been accepted for maintenance as a street by the county.

Street right-of-way line means the dividing line between a lot, tract or parcel of land and a street right-of-way.

Structure means anything constructed or erected with a fixed location on the ground, or attached to something having a fixed location on or in the ground. This does not include telephone poles and utility boxes.

Structural erosion and sedimentation control measures mean measures for the stabilization of erodible or sediment-producing areas by utilizing the mechanical properties of matter for the purpose of either changing the surface of the land or storing, regulating or disposing of runoff to prevent excessive sediment loss. Examples of structural erosion and sediment control practices are riprap, sediment basins, dikes, level spreaders, waterways or outlets, diversions, grade stabilization structures, sediment traps and land grading. Such measures can be found in the publication "Manual for Erosion and Sediment Control in Georgia."

Subdivision means any division or redivision of a lot, tract or parcel, regardless of its existing and future use, into two (2) or more lots, tracts or parcels. Where appropriate to context, subdivision may also be used to reference the aggregate of all lots held in common ownership at the time of division.

Substantial damage means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed fifty (50) percent of the market value of the structure before the damage occurred.

Substantial improvement means any combination of repairs, reconstruction, alteration or improvements to a structure taking place during the life of a structure, the cumulative cost of which equals or exceeds fifty (50) percent of the market value of the structure. The market value of the structure should be the appraised value of the structure prior to the start of the initial repair or improvement or, in the case of damage, the value of the structure prior to the damage occurring. This term includes structures that have incurred substantial damage regardless of the actual repair work performed. For the purposes of this definition, substantial improvement is considered to occur when the first alteration of any wall, ceiling, floor or other structural part of the structure commences, whether or not that alteration affects the external dimensions of the structure. The term does not, however, include any project for improvement of a building required to comply with existing state or local health, sanitary, or safety code specifications which have been identified by a code enforcement official and which are solely necessary to assure safe living conditions, or any alteration to a structure listed on the National Register of Historic Places or a state inventory of historic places.

Substantially improved existing manufactured home parks or subdivision is where the repair, reconstruction, rehabilitation or improvement of the streets, utilities and pads equals or exceeds fifty (50) percent of the value of the streets, utilities and pads before the repair, reconstruction or improvement commenced.

SWCD means the Soil and Water Conservation District of DeKalb County.


Tree means any living, self-supporting, woody perennial plant which has a trunk caliper of two (2) inches or more measured at a point six (6) inches above the ground and which normally attains a height of at least ten (10) feet at maturity usually with one (1) main stem or trunk and many branches.

Tree harvesting means the felling, loading, and transporting of timber products done pursuant to a special exception issued by the zoning board of appeals.

Tree save area means the boundaries of the area or areas surrounding trees wherein it is essential that they remain undisturbed in order to prevent damage and loss of trees that are to be retained on site during the development and building process.

Tree replacement means the replacement of trees and landscape plant materials into the minimum required landscape areas, as determined by the zoning regulations or the tree protection ordinance.

Thoroughfare plan means a comprehensive street plan of the county indicating proposed location and right-of-way widths for major thoroughfares, minor thoroughfares, collector streets and other streets.


Undeveloped land shall mean a lot in its unaltered natural state and which has no pavement, asphalt, or compacted gravel surfaces or structures which create an impervious surface that would prevent infiltration of stormwater or cause stormwater to collect, concentrate, or flow in a manner materially different than that which would occur if the land was in an unaltered natural state.

Unpolluted shall mean the absence of pollution.

Used for includes the phrases "arranged for," "designed for," "intended for," "maintained for" and "occupied for."


Vegetation means all plant growth, especially trees, shrubs, vines, ferns, mosses and grasses.

Vegetative erosion and sedimentation control practices means practices for the stabilization of erodible or sediment producing areas by covering the soil with: (1) permanent seeding, sprigging or planting, producing long-term vegetative cover; or (2) temporary seeding, producing short-term vegetative cover; or (3) sodding, covering areas with a turf of perennial sod-forming grass. Such practices can be found in the publication "Manual for Erosion and Sediment Control in Georgia" published by the Georgia Soil and Water Conservation Commission.


Water Quality requirements shall mean the design, construct and maintain stormwater facilities that meet the requirements of the Georgia Stormwater Management manual to treat runoff from all storms of 1.2 inch or less precipitation depth to a level that will reduce the Total Suspended Solids load from the affected impervious area by an annual amount of 80 percent.

Water quantity shall mean those characteristics of stormwater that relate to the rate and volume of the stormwater, both surface and subsurface.

Watercourse means any natural or artificial watercourse, stream, river, creek, channel, ditch, canal, conduit, culvert, drain, waterway, gully, ravine, or wash in which water flows either continuously or intermittently and which has a definite channel, bed and banks, and including any area adjacent thereto subject to inundation by reason of overflow or floodwater.

Wetlands means those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas.

Work orders related to stormwater management include maintenance and repair of stormwater facilities for which the County has responsibility, or those additional activities needed for public health and safety.  These activities are performed by County infrastructure crews and are funded through the annual operating budget.