§ 30-1722. Definitions.

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

Adverse impacts, stormwater management, means modifications, alterations, or effects on groundwater or surface water or wetlands, including quality, quantity, hydrodynamics, i.e., currents, flow patterns, surface area, species composition, living resources, or usefulness, which are or may be potentially harmful to human health and safety, or to biological productivity or stability, or which interfere with lawful enjoyment of life or property, including secondary, cumulative, and direct impacts.

Best management practices (BMPs), stormwater management, means those methods of stormwater management recognized by experts in the field as the most effective for treating or managing stormwater runoff. Refer to Florida Development Manual: A Guide to Sound, Land and Water Management, chapter 6, Stormwater and Erosion and Sediment Control Best Management Practices for Developing Areas.

Bleed-down device (orifice) means a discharge conveyance structure associated with detention facilities that allows stormwater attenuation volumes to be recovered.

Canal means an artificial waterway constructed for use by boats, for irrigation, or for recreational use.

Control elevation means the lowest point above sea level at which water can be released through the control structure.

Control structure means the element of a discharge structure which allows the gradual release of water under controlled conditions.

Credit means compensation for providing pervious or infiltration capacity which is incorporated into alternative stormwater treatment technology.

Detention means the delay of stormwater runoff prior to discharge into receiving waters.

Detention facility means a stormwater management structure or structures which provides for the delay of movement or flow of a specified volume of stormwater for a specified period of time.

Direct discharge means the release of stormwater through a control structure to a receiving water body.

Discharge structure means a device through, or over, which water is released from a stormwater management structure.

Drain means a channel, pipe, or other structure for the purpose of conveying water.

Drainage means removal of water from an area for the purpose of lowering the water level of that area.

Drawdown means change in surface water elevation within a stormwater management facility in response to its discharge. For retention facilities, drawdown represents the amount of surface water elevation change in response to infiltration. For detention facilities, drawdown represents the amount of surface water elevation change in response to discharge from a bleed-down device (orifice).

Engineer means a person registered and currently licensed to practice professional engineering in the state and other persons pursuant to the provisions of F.S. ch. 471 who are competent in the field of hydrology and stormwater management.

Erosion means the detachment and movement of soil particles from their original location.

Evaporation means the process by which any substance is converted from a liquid state into, and carried off in, vapor, i.e. evaporation of water.

Frequency means the anticipated cyclic return period of a storm event, e.g., 25-year storm.

Hydrograph means a graph depicting the flow rate of a discharge.

Impervious surface means a surface which does not allow, or minimally allows, the penetration of water into the ground; included as examples are: building roofs; normal concrete and asphalt pavements; and some fine-grained soils, such as clays.

Indirect discharge means release of stormwater from a system by means other than a control structure.

Maintenance means action taken to restore or preserve the functional intent of any stormwater facility or drainage structure or system.

Manmade water body means a water body that was created by excavation using mechanical means under human control and shall include a canal, cut basin or channel where its edges or margins have subsequently been modified by natural forces.

Operational entity means an acceptable, legally bound, responsible organization which agrees to operate and maintain the stormwater management system.

Pre-condition for stormwater runoff means topography, vegetation, rate, volume, direction and pollution load of surface water or groundwater flow existing immediately prior to development or redevelopment of a parcel.

Receiving body of water means a water body, watercourse, or wetland to which surface or discharge water flows.

Retention means the storage of a specific volume of stormwater runoff within a defined area having no direct discharge into receiving waters; included as examples are systems which discharge through percolation, drawdown, and evaporation processes.

Runoff coefficient (C) means the standardized factor from which runoff can be calculated.

Seasonal high water table means the groundwater level during the time of year when the greatest amount of rainfall normally occurs.

Sediment means solid material that settles to the bottom of a water body or is deposited when erosive velocity ceases.

Spreader swale means a properly designed and legally permitted drainage structure which has an underlying bed of rock positioned parallel to the receiving water body which allows for indirect discharge of stormwater in excess of the retained or detained volume.

Storm event means the occurrence of a rainfall of specified frequency and duration, e.g. 25-year/72-hour storm.

Stormwater management plan means the detailed analysis describing how the rainfall control system for the proposed development has been planned and designed and shall be constructed to meet the requirements of this division.

Stormwater management system means the natural and constructed features of the property which are designed to treat, collect, convey, channel, hold, inhibit, or divert the movement of surface water.

Stormwater runoff means that volume of rainfall which does not percolate into the ground, nor evaporates, nor is intercepted before reaching the stormwater management system.

Substantial increase in impervious area means an increase in impervious area greater than 1,000 square feet that is not adjacent to a canal or other water body or greater than 500 square feet that is adjacent to a canal or water body.

Surface water. See Water body .

Swale means a shallow constructed ditch depression with the bottom above the water table.

Tailwater means water located directly downstream from a surface water structure on a river, stream or creek.

Vegetative swale means a shallow constructed ditch depression with the bottom above the water table which is planted with greater than 90 percent vegetation.

Water body and surface water mean a natural or artificial watercourse, canal, pond, bay, and coastal waters of the village extending to a landward limit defined by F.A.C. 17-4.022 and F.S. § 403.031.

Water table means the subsurface boundary between the zone of saturation and the zone of aeration; it varies with such factors as tide and the amount of rainfall.

Watercourse means a channel, canal or stream bed, either natural or manmade, which is involved in the accommodation of floodwaters.

Wet detention means the delay of stormwater runoff prior to discharge into receiving waters in a structure with a bottom elevation below the water table or control elevation.

Wetlands is defined as provided in F.S. § 403.911.

(Ord. No. 02-15, § 1(7.7.2), 2-14-2002)

Cross reference

Definitions generally, § 1-2.