§ 14-21. 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:

Coefficient of runoff means a number used as a multiple in measuring the change in stormwater runoff.

Detention means temporary storage of stormwater runoff and the subsequent slow release of the water to drainageways, groundwater percolation or evaporation. Detention facilities shall also be for the purpose of reducing peak rates in down stream facilities.

Developer means the owner of the property or his agent engaged in the subdivision or improvement of, or construction of structures upon land within the jurisdiction of the county.

Development means the results of improvements made to raw land to convert the primary use of the land to that of a residential or commercial subdivision, shopping center, apartment or townhouse/condominium complex. The term "development" also means any other major improvements which substantially change the use of the land such as the redevelopment of an existing area or a renewal project.

Drainage basin means a drainage area or watershed contributing to the flow of water in a receiving body of water.

Drainage facilities means any existing or proposed improvement installed for the purpose of conveying stormwater or run off such as watercourses, storm drain pipe, culverts, sewers specifically designated to handle stormwater, open ditches or swales either with paved inverts or without, and all appurtenances to said works.

Gross acre means all land under single title or ownership and recorded with the property deed and consisting of contiguous acreage.

Impervious surface means a surface which has been compacted or covered with a layer of material so that it is highly resistant to infiltration by water. It includes, but is not limited to, surfaces such as compacted clay, as well as most conventionally surfaced streets, roofs, sidewalks, parking lots, patios, swimming pool decks and other similar structures.

Inverted crown section means a road or street cross section where the center of the road or street profile is lower than the edges of the profile to allow for stormwater to drain toward the center of the road or street for removal through a stormwater drainage system.

Lined channels means the use of plastics, concrete, stone, asphalt or similar material to define a drainage channel.

Littoral vegetation means vegetation found off, on or along the shore of surface water.

Major drainage channels means all channels which drain an accumulation of primary and/or secondary drainage channels. These channels shall be the natural drainage channels of the watershed or manmade channels draining an area of one square mile or more.

Manmade waterbody means any manmade pond, lake, lagoon, channel, wetland, marina, or basin which ordinarily or intermittently contains water and which has a discernible shoreline.

Natural waterbody means any natural pond, lake, channel, wetland, marsh or creek, which ordinarily or intermittently contains water and which has a discernible shoreline.

On site means on or within the area contained in the development permit application or within other areas which, pursuant to this article may be included in defining the site's said referenced purpose.

Peak flow, for runoff, means at the time of greatest runoff concentration, the volume of velocity in cubic feet per second (cfs) being discharged at a given point.

Pre-development conditions means those conditions which existed before alteration, resulting from human activity, of the natural topography, vegetation and rate, volume or direction of surface water or groundwater flow as indicated by the best available historical data.

Primary drainage channels means all drainage channels which drain an area of 200 acres or more.

Receiving waters means any waterbodies, watercourses or wetlands into which surface waters flow either naturally, in manmade ditches, or in a closed conduit system.

Responsibility for improvements. It is intended by this definition that the improvements of primary drainage shall be the long range responsibility of the developer and the community as a whole, since the developer and the whole community are benefited materially. The developer of land or improvements within an area containing a primary drainage channel shall design, plan and carry out his developments in a manner that will not interfere with or restrict the natural flow of water or materially change the conditions of run off within the calculated area below the 100 year maximum flood elevation. Increased runoff and changes in primary channels which are created by such developments within primary drainage areas shall be made in accordance with the provisions of this section. The improvements of secondary drainage channels shall be the responsibility of the developer, since the primary benefit is to the area served by the secondary channel and not to the community as a whole.

Retention means storage of stormwater runoff in a facility that has a relatively permanent minimum water level for the purpose of reducing peak runoff in downstream facilities.

Secondary drainage channels means all drainage channels which drain an area of less than 200 acres and the primary benefit is to the development.

Sediment means fine particulate material, whether mineral or organic, that is temporarily in suspension or has settled in a waterbody.

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

(Ord. No. 84-49, § 1, 4-16-1984)