For the purposes of this chapter, the following terms, phrases, words, and their derivatives shall have the meaning stated below:
BEST MANAGEMENT PRACTICES (BMPS). Techniques or series of techniques which are proven to be effective in controlling runoff, erosion and sedimentation, and in mitigating flooding. This includes but is not limited to detention ponds, extended detention ponds, swales, bioretention systems, vegetated filters, and hydrodynamic separators. This term can be interchangeable with the term STORMWATER MANAGEMENT FACILITIES.
COUNTY. Means Oldham County Fiscal Court, a county employee, representative or designated person or agency. It may include the County Engineer, County Judge Executive, County Attorney, Road Supervisor, code enforcement officer, Deputy Judge/Executive, employee of the Planning and Development Office such as the Director, Planner or Building Inspector.
DESIGN STORM. A rainfall event of specified size and return frequency (e.g., a storm that occurs only once every two years) that is used to calculate the runoff volume and peak discharge rate to a BMP.
DETENTION BASIN. A temporary or permanent, natural or manmade structure that provides for the temporary storage of stormwater runoff, designed to prevent the permanent pooling of water.
DEVELOPER. Any person, firm, corporation, sole proprietorship, partnership, state agency, or political subdivision thereof engaged in a land disturbance activity.
DITCH. An excavation, either dug man-made or natural, for the purpose of drainage or irrigation or having intermittent flow.
DRAINAGE AREA. An area enclosed by a topographic feature that contributes runoff to a single point that is measurable in a horizontal plane.
GREEN INFRASTRUCTURE BMPS. Types of structural BMPs that enhance the potential for infiltration and evapo-transpiration. GREEN INFRASTRUCTURE BMPS are intended to treat, filter, flocculate, infiltrate, screen, evapo-transpire, harvest and reuse stormwater runoff, or otherwise manage the stormwater runoff quality. GREEN INFRASTUCTURE BMPS can be implemented to meet the water quality treatment standard, and typically include, but are not limited to, the following:
(1) Grass swales;
(2) Filter strips;
(3) Infiltration basins;
(4) Dry, wet, and extended-wet detention ponds;
(5) Stormwater wetlands;
(6) Bioretention areas;
(7) Natural infiltration areas;
(8) Sand filters;
(9) Pervious pavements; or
(10) Rain gardens.
IMPERVIOUS COVER. Any surface that cannot effectively absorb or allow water to infiltrate. This may include roads, streets, parking lots, rooftops and sidewalks.
INFILTRATION. The passage or movement of water into the soil surface.
INTENSITY-DURATION-FREQUENCY CURVE (IDF CURVE). A graphical representation of the probability that a given average rainfall intensity will occur.
LAND DISTURBANCE ACTIVITY. Any construction-related land change that may result in soil erosion from wind, water and/or ice, and the movement of sediments into or upon waters, lands, or rights of way within the county, including, but not limited to, construction, demolition, clearing and grubbing, grading, excavating, transporting, and filling of land.
MAJOR SUBDIVISION DEVELOPMENT PLAN. A contiguous area where multiple separate and distinct construction activities are planned to occur at different times on different schedules under one plan. This includes commercial as well as residential development.
MUNICIPAL SEPARATE STORM SEWER SYSTEM (MS4). A conveyance, or system of conveyances including roads with drainage systems, municipal and county maintained roadways, catch basins, curbs, gutters, ditches, man-made channels, and storm drains designed or used for collecting and/or conveying stormwater. Sanitary and combined sewers are not included in the definition of a MUNICIPAL SEPARATE STORM SEWER SYSTEM.
ONE HUNDRED-YEAR STORM. A storm that is capable of producing rainfall expected to be equaled or exceeded on the average of once in 100 years. It may also be expressed as a storm having the probability of a 1% chance of being equaled or exceeded in any given year.
OWNER. An individual or entity in possession of title for land, building, or other item.
POST-DEVELOPMENT. The conditions which exist following the completion of the land disturbance activity in terms of topography, vegetation, land use, and runoff rate, volume or direction.
PRE-DEVELOPMENT. The conditions which existed prior to the initiation of the land disturbance activity in terms of topography, vegetation, land use, and runoff rate, volume or direction.
REDEVELOPMENT. Any construction, alteration, or improvement involving land disturbance activity performed on sites where existing land use is commercial, industrial, institutional, or multifamily residential.
RETENTION BASIN. A temporary or permanent, natural or manmade structure that provides for the storage of stormwater runoff by means of a permanent pool of water.
RUNOFF. Any water flowing over ground surface, including, but not limited to, rainfall, snowmelt or irrigation water.
RUNOFF CALCULATION METHODS. Mathematical models and equations that are used to predict runoff volumes and rates.
SEDIMENT. Soils or other superficial materials transported or deposited by surface water as a product of erosion.
STORMWATER CONVEYANCE SYSTEM. All storm sewers, channels, streams, ponds, lakes, or other conveyances used for conveying concentrated stormwater runoff or for storing stormwater runoff.
STORMWATER MANAGEMENT. The overall culmination of techniques used to reduce surface runoff from causing flooding and dispersing pollutants. STORMWATER MANAGEMENT limits these negative impacts on the environment and property and should meet the hydraulic needs of a development while minimizing the associated negative environmental impacts.
STORMWATER MANAGEMENT FACILITIES. Control the discharge of stormwater and may remove pollutants. STORMWATER FACILITIES include storage facilities (ponds, vaults, underground tanks, infiltration systems, etc.); water quality facilities (wet ponds, biofiltration swales, constructed wetlands, sand filters, oil/water separators, etc.); and conveyance systems (ditches, pipes, catch basins, etc.). These facilities can also be referred to by the term BEST MANAGEMENT PRACTICES (BMP).
STREAM. Any river, creek, or channel in which water flows for substantial periods of the year.
SURETY. A guarantee given by the owner to insure that they will meet the required obligations. Acceptable sureties are an irrevocable letter of credit in favor of the appropriate legislative body from a bank with offices in the Commonwealth of Kentucky, a performance bond in favor of the appropriate legislative body from a reputable bonding company acceptable to the administrating authority, or a cash security in favor of the appropriate legislative body may be presented to the administrating authority as an acceptable surety. Any irrevocable letter of credit or performance bond must include an automatic renewal "evergreen" clause with at least 30 day notice to the county of the cancellation of the surety. For the purposes of these regulations, the term BONDING shall be construed to also include the posting of a letter of credit or cash as surety.
TEN-YEAR STORM. A storm that is capable of producing rainfall expected to be equaled or exceeded on the average of once in ten years. It may also be expressed as a storm having the probability of a 10% chance of being equaled or exceeded in any given year.
TWO-YEAR STORM. A storm that is capable of producing rainfall expected to be equaled or exceeded on the average of once in two years. It may also be expressed as a storm having the probability of a 50% chance of being equaled or exceeded in any given year.
WATER QUALITY TREATMENT STANDARD. The requirement intended to provide water quality treatment to the stormwater runoff volume from the 80th percentile precipitation event, equivalent to a rainfall event of 0.6 inches. The WATER QUALITY TREATMENT STANDARD requires the stormwater runoff volume from this rainfall event to completely pass through a stormwater management measure or green infrastructure BMP prior to discharging from a development or re-development site.
(Ord. 16-830-348, passed 8-16-2016)