§ 74-503. Definitions.

The following words, terms and phrases, when used in this article, shall have the meanings ascribed to them in this section, except where the context clearly indicates a different meaning:

Applicant means a person submitting a post-development stormwater management application and plan for approval.

Channel means a natural or artificial watercourse with a definite bed and banks that conducts continuously or periodically flowing water.

Commissioner means the commissioner of the department of watershed management or a designee.

Conservation easement means an agreement between a land owner and the City of Atlanta, other government agency, or land trust that permanently protects open space or greenspace on the owner's land by limiting the amount and type of development that can take place, but continues to leave the remainder of the fee interest in private ownership.

Demolition means removal of an existing building, structure, or other impervious surface.

Detention means the temporary storage of stormwater runoff in a stormwater management facility for the purpose of controlling the peak discharge.

Detention facility means a detention basin or structure designed for the detention of stormwater runoff and gradual release of stored water at controlled rates.

Developer means a person who undertakes land development activities.

Development means a land development or land development project.

Drainage easement means an easement appurtenant or attached to a tract or parcel of land allowing the owner of adjacent tracts or other persons to discharge stormwater runoff onto the tract or parcel of land subject to the drainage easement.

Erosion and Sedimentation Control Plan means a plan that is designed to minimize the accelerated erosion and sediment runoff at a site during land disturbance activities.

Extended detention means the detention of stormwater runoff for an extended period, typically 24 hours or greater.

Extreme flood protection means measures taken to prevent adverse impacts from large low-frequency storm events with a return frequency of 100 years or more.

Flooding means a volume of water that is too great to be confined within the banks or walls of a conveyance or stream channel and overflows onto adjacent lands.

Grading means altering ground surfaces to specified elevations, dimensions and slopes; this includes, but is not limited to, stripping, cutting, filling, stockpiling and shaping or any combination thereof and includes the land in its cut or filled condition.

Greenfield means land in its natural condition.

Greenspace means permanently protected areas of the site that are preserved in a vegetated state.

Green infrastructure means an interconnected natural system and/or engineered system that strengthens and mimics natural hydrologic functions and processes through the use of plants and soil to slow, filter, evapotranspire, and infiltrate stormwater runoff close to its source; or the capture and reuse of stormwater runoff.

High risk operation means an area where the use of the land has the potential to generate highly contaminated runoff, with concentrations of pollutants in excess of those typically found in stormwater as consistent with facilities operating under a Standard Industrial Code (SIC) or requiring coverage under the Georgia General NPDES Stormwater Permit for Discharges from Industrial Activities or as identified as a highly visible pollutant source (HVPS) per the City of Atlanta's Stormwater Management Plan (SWMP) developed in accordance with the requirements of the City of Atlanta's NPDES Municipal Separate Storm Sewer System (MS4) permit.

Hotspot means an area with, or having potential for a high level of pollution and/or contamination within a larger area of low adverse environmental impact or normal environmental quality.

Hydrologic Soil Group (HSG) means a natural resource conservation service classification system in which soils are categorized into four runoff potential groups. The groups range from group A soils, with high permeability and little runoff produced, to group D soils, which have low permeability rates and produce much more runoff.

Impervious cover means a surface composed of any material that significantly impedes or prevents the natural percolation of water into soil, which includes, but is not limited to, rooftops, buildings, streets and roads, and standard concrete or asphalt surface.

Industrial stormwater permit means a National Pollutant Discharge Elimination System (NPDES) permit issued to an entity which regulates the pollutant levels associated with industrial stormwater discharges or specifies on-site pollution control strategies.

Inspection and maintenance agreement means a written agreement providing for the long-term inspection and maintenance of stormwater management facilities and practices on a site or with respect to a land development project, which, when properly recorded in the deed records of the Superior Court of Fulton or DeKalb County, whichever is applicable, constitutes a restriction on the title to a site or other land involved in a land development project.

Jurisdictional wetland means an area that is inundated or saturated by surface water or groundwater at a frequency and duration sufficient to support a prevalence of vegetation typically adapted for life in saturated soil conditions, commonly known as hydrophytic vegetation, as determined by the U.S. Army Corps of Engineers.

Land development means any land change, including, but not limited to, clearing, digging, grubbing, stripping, removal of vegetation, dredging, grading, excavating, transporting and filling of land, construction, paving, and any other installation of impervious cover.

Land development activities means those actions or activities which comprise, facilitate or result in land development.

Land development project means a discrete land development undertaking.

National Pollutant Discharge Elimination System (NPDES) Permit means the applicable national pollutant discharge elimination system permit issued by the State Environmental Protection Division and in effect at the time of application for a post-development stormwater plan approval.

New development means a land development activity on a previously undeveloped site.

Nonpoint source pollution means a form of water pollution that does not originate from a discrete point such as a sewage treatment plant or industrial discharge, but involves the transport of pollutants such as sediment, fertilizers, pesticides, heavy metals, oil, grease, bacteria, organic materials and other contaminants from land to surface water and groundwater via mechanisms such as precipitation, stormwater runoff, and leaching. Nonpoint source pollution is a by-product of land use practices such as agricultural, silvicultural, mining, construction, subsurface disposal and urban runoff sources.

Nonstructural stormwater management practice means any natural or planted vegetation or other nonstructural component of the stormwater management plan that provides for or enhances stormwater quantity and/or quality control or other stormwater management benefits and includes, but is not limited to, riparian buffers, open and greenspace areas, overland flow filtration areas, natural depressions, and vegetated channels.

Off-site facility means a stormwater management facility located outside the boundaries of the site.

On-site facility means a stormwater management facility located within the boundaries of the site.

Overbank flood protection means measures taken to prevent an increase in the frequency and magnitude of out-of-bank flooding (i.e. flow events that exceed the capacity of the channel and enter the floodplain), and that are intended to protect downstream properties from flooding up to the 25-year frequency storm events.

Owner means the legal or beneficial owner of a site, including but not limited to, a mortgage or vendee in possession, receiver, executor, trustee, lessee or other person, firm or corporation in control of the site.

Percolation means the process of absorption of stormwater runoff into the subsoil.

Permit means the permit issued by the City of Atlanta to the applicant which is required for undertaking any land development activity.

Person means, except to the extent exempted from this article, any individual, partnership, firm, association, joint venture, public or private corporation, trust, estate, commission, board, public or private institution, utility, cooperative, city, county or other political subdivision of the state, any interstate body or any other legal entity.

Post-development refers to the time period, or the conditions that may reasonably be expected or anticipated to exist, after completion of the land development activity on a site as the context may require.

Pre-development refers to the time period, or the conditions that exist, on a site prior to the commencement of a land development project and at the time that plans for the land development of a site are approved by the City of Atlanta. Where phased development or plan approval occurs, which includes but is not limited to demolition, preliminary grading, roads and utilities, the existing conditions at the time prior to issuance of the first project-related approval or permit shall represent pre-developed conditions, in accordance with section 74-513(d).

Project means the portion of the proposed development in terms of the area of land to be disturbed.

Q means the peak rate of discharge.

Redevelopment means a land development project or addition on a previously developed site.

Regional stormwater management facility means stormwater management facilities designed to control stormwater runoff from multiple properties, where the owners or developers of the individual properties may assist in the financing of the facility, and the requirement for site-specific on-site controls may be either eliminated or reduced.

Responsible party means the owner or owner's agent.

Runoff means the flow of surface water resulting from precipitation.

Runoff reduction means the interception, evapotranspiration, infiltration or capture and reuse of stormwater runoff.

Single-family residential development means development or redevelopment of a lot containing a single one- or two-family dwelling as defined in section 16-29.001(12) of the City of Atlanta's Zoning Ordinance.

Site means the parcel of land being developed, or the portion thereof on which the land development project is located.

Stormwater better site design means nonstructural site design approaches, practices and techniques that can reduce a site's impact on the watershed and can provide for nonstructural stormwater management. Stormwater better site design includes conserving and protecting natural areas and greenspace, reducing impervious cover and using natural features for stormwater management.

Stormwater management means the collection, retention, detention, conveyance, storage, treatment and disposal of stormwater runoff in a manner intended to prevent increased flooding, streambank channel erosion, habitat degradation and water quality degradation, and to enhance and promote the public health, safety and general welfare.

Stormwater management facility means any infrastructure that controls or conveys stormwater runoff.

Stormwater management measure means any stormwater management facility or nonstructural stormwater practice.

Stormwater management plan means the document(s) describing how existing runoff characteristics will be affected by a land development project and containing measures for complying with the provisions of this article.

Stormwater management site plan means an engineering drawing depicting how and where stormwater management facilities and practices will be installed on the site.

Stormwater management system means the entire set of structural and nonstructural stormwater management facilities and practices that are used to capture, convey and control the quantity and quality of the stormwater runoff from a site.

Stormwater retrofit means a stormwater management practice designed for a currently developed site that previously had either no stormwater management practice in place or a practice inadequate to meet the stormwater management requirements of the site.

Structural stormwater control means a structural stormwater management facility or device that controls stormwater runoff and changes the characteristics of that runoff including, but not limited to, the quantity and quality, the period of release, or the velocity of flow of such runoff.

Subdivision means the division of a tract or parcel of land resulting in one or more new lots or building sites for the purpose; whether immediately or in the future, of sale, other transfer of ownership or land development, and includes divisions of land resulting from or made in connection with the layout or development of a new street or roadway or a change in an existing street or roadway.

(Ord. No. 2004-56, §§ 2—4, 9-15-04; Ord. No. 2013-05(12-O-1761), § 3, 2-13-13)