For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.
BANKFUL ELEVATION. It is the water level, or stage at which the stream, river or lake is at the top of its banks and any further rise would result in water moving into the floodplain.
BEST MANAGEMENT PRACTICES (BMP). They are a schedule of activities prohibitions of practices, maintenance procedures and other management practices, which are proved to be effective in preventing or reducing runoff, erosion and sedimentation.
DETENTION FACILITY. Any structure which is designed to collect and store surface water for subsequent gradual discharge.
DRAINAGE FACILITY. Any component of the drainage system.
EXCESS STORMWATER RUNOFF. That portion of stormwater which exceeds the safe storm drainage capacity of storm sewers or natural drainage channels serving a specific watershed.
IMPERVIOUS AREAS. The horizontal-projected plain area of roof and paved areas of all permanently constructed roofs of houses, garages, mobile homes, businesses, industries, paved driveways, patios and parking lots, but does not include non-permanent structures such as temporary buildings and tents. Also excluded are impervious areas of stored materials and equipment, swimming pools, ponds and lakes; and stormwater retention and detention basins. Gravel or rock roads and gravel or rock parking areas are not considered as impervious areas.
PROTECTED CHANNEL. A channel which receives stormwater discharge and which is paved, rip-rapped, or otherwise improved by addition of man-made materials so as to reduce the potential for erosion.
SAFE STORM DRAINAGE CAPACITY. The quantity of stormwater runoff that can be transported by a channel or conduit without giving the water surface rise above the top of the channel and conduit.
STORMWATER CHANNEL. A natural or man-made open watercourse with definite bed and banks which periodically or continuously contains moving water, or which forms a connecting link between two bodies of water.
STORMWATER RUNOFF. Water that results from precipitation, which is not absorbed by the soil or vegetation or evaporated, and which flows over the ground surface or is collected in channels or conduits.
STORMWATER RUNOFF RELEASE RATE. The rate at which stormwater runoff is released from dominant to servient land.
TWENTY-FIVE-YEAR, 24-HOUR FREQUENCY RAINFALL. A precipitation event of 24-hours duration, having a 4% chance of occurring in any one year.
COMPLIANCE WITH OTHER REQUIREMENTS. Before starting any activities regulated by this chapter, an applicant shall comply with the requirements set forth in other applicable ordinances with respect to the submission and approval of preliminary and final subdivision plats, improvement plans, building and zoning permits, inspections, appeals and similar matters, along with those set forth in this chapter and as may be required by state statutes and the regulations of any department of the Commonwealth of Kentucky.
STORMWATER MANAGEMENT PLAN.
(1) A stormwater management plan shall be required for any new single-family residential development having a gross aggregate area, including roads, utility rights-of-way, and any other dedicated land of five or more acres, and having a density of greater than one dwelling unit per acre or for any new commercial, multi-family residential, industrial, institutional or utility development having a gross aggregate area of 0.5 acres or more. A plan shall also be required for any new development or redevelopment of fully developed areas as designated on the watershed drainage map. The official watershed drainage map shall be kept in the office of the Stormwater Manager. No final subdivision plat shall be approved and no building permits shall be issued until and unless the stormwater management plan has be reviewed and approved by the Stormwater Manager. Owners of residential property within subdivisions for which final subdivision plats have approved prior to the date of the approval of this chapter shall not be required to comply with this chapter. The Stormwater Manager may also require stormwater management plans for any drainage area if adverse impacts are anticipated. A stormwater management plan may also be required prior to any grading or excavation which would fill, obstruct or otherwise alter any creek, stormwater channel or drainage facility.
(2) The required Stormwater Management Plan shall identify means for controlling the stormwater runoff release rate from the development and providing storage potential for the excess stormwater runoff (where required). All computations, plans and specifications related to the implementation of this chapter must be prepared and sealed by a professional engineer registered in the state.
(Ord. 2809, passed 12-10-2012)