§ 156.15 STORMWATER MANAGEMENT PLAN.
   (A)   A stormwater management plan shall be required for any new single-family residential developments having a gross aggregate area, including roads, utility rights-of-way, and any other dedicated lands 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; provided that all such development is located in areas designated as "severe" or "high" on the watershed drainage map. 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 City Civil Engineer. No final subdivision plat shall be approved and no building permits shall be issued until and unless the stormwater management plan has been reviewed and approved by the City Civil Engineer. Owners of residential property within subdivisions for which final subdivision plats have been approved prior to the date of the approval of this chapter shall not be required to comply with this chapter. The City Civil Engineer or his or her duly authorized designees 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.
   (B)   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.
      (1)   Requirements for controls of runoff for projects under construction/new construction. The following best management practices, which address the problem of urban runoff, shall apply to all projects undergoing construction in the city. The best management practices list set forth below is the minimum required by the city. Any BMP or BMP Plan utilized shall be equal to or more effective than the BMPs contained in the Kentucky Erosion Prevention and Sediment Control Manual and Field Guide. The requirements set forth below shall apply at the time of demolition of an existing structure or commencement of construction and until receipt of a certificate of occupancy:
         (a)   Runoff sediment and construction waste from construction sits and parking areas shall not leave the site;
         (b)   Any sediments or other materials which are tracked off the site shall be removed the same day as they are tracked off the site. Where determined by the City Civil Engineer or his or her designated representative, a temporary sediment barrier shall be installed;
         (c)   On an emergency basis only, plastic covering may be utilized to prevent erosion of an otherwise unprotected area, along with runoff devices to intercept and safely convey the runoff.
         (d)   Excavated soil shall be located on the site in a manner that eliminates the possibility of sediments running into the street or adjoining properties. Soil piles shall be covered until the soil is either used or removed. A plastic or micromesh fabric should be used;
         (e)   No washing of construction or other industrial vehicles shall be allowed adjacent to a construction site. No runoff from washing vehicles on a construction site is allowed to leave the site;
         (f)   Drainage controls shall be utilized as needed, depending on the extent of proposed grading and topography of the site, including but limited to the following:
            1.   Detention ponds, sediment ponds, or infiltration pits;
            2.   Dikes, filter berms, silt fences, or ditches;
            3.   Down drains, chutes or flumes.
      (2)   Observe basic principles such as:
         (a)   Preserve existing vegetation as much as possible;
         (b)   Mulch or seed bare soil immediately for the best and cheapest erosion protection;
         (c)   Use silt fences, brush barriers, or other approaches to pond and filter sediment from runoff;
         (d)   Install silt check dams made of rock, brush, or other products to prevent ditch erosion and remove sediment;
         (e)   Protect inlets and outlets; and
         (f)   Settle out soil particles in sediment traps and basins.
   (C)   The stormwater management plan shall contain, but not be limited to, the following information unless specifically excluded by the City Civil Engineer.
      (1)   A topographic map of the project site and adjacent areas, of suitable scale and contour interval, which shall define the location of streams, the extent of flood plains and calculated high water elevations, the shoreline of lakes, ponds, swamps and detention basins including their inflow and outflow structures, if any.
      (2)   The location and flowline elevation of all existing sanitary, storm, or combined sewers.
      (3)   Detailed determination of runoff anticipated for the entire project site following development indicating design volumes and rates of proposed runoff for each portion of the watershed tributary to the storm drainage system, the calculations used to determine said runoff volumes and rates and restatement of the criteria which have been used by the project engineer throughout calculations.
      (4)   A layout of the proposed stormwater management system including the location and size of all drainage structures, storm sewers, channels and channel sections, detention basins, and analyses regarding the effect said improvements will have upon the receiving channel and its high water elevation.
      (5)   The slope, type, and size of all existing and proposed storm sewers and other waterways impacting or impacted by the proposed development on the site.
      (6)   For all detention basins, a plot or tabulation of storage volumes with corresponding water surface elevations and of the basin outflow rates for those water surface elevations.
      (7)   For all detention basins, design hydrographs of inflow and outflow for the two, ten, and 25-year events for the site under existing and developed conditions.
      (8)   A profile and one or more cross sections of all existing and proposed channels or other open drainage facilities, showing existing conditions and the proposed changes thereto, together with the high water elevations expected from stormwater runoff under the controlled conditions called for by these regulations and the relationship of structures, streets, and other utilities to such channels.
      (9)   Show specific erosion control methods to be utilized during construction.
      (10)   Total area of the site and total area of disturbance. To find out further about required information, obtain checklists and other technical and guidance documents from the City Engineering Department further required information.
   (D)   Stormwater Pollution Prevention Plan (SWPPP). Any land disturbing activity that disturbs 0.5 acres of land or more is required to submit a SWPPP to the Office of the City Civil Engineer. For all sites that disturb one acre or more, a notice of intent (NOI) must be filed with the Kentucky Division of Water as well as the SWPPP prior to any disturbance. The NOI and SWPPP shall be submitted with the design plans and stormwater management plan to the Office of the City Civil Engineer. The SWPPP shall include sufficient information to evaluate the environmental characteristics of the affected areas, the potential impacts of the proposed grading on water resources, and measure proposed to minimize soil erosion and off-site sedimentation. The owner/developer, contractor shall perform all clearing, grading, drainage, construction, and development in strict accordance with the approved plan and this chapter.
      (1)   The SWPPP shall include all items required in this chapter and as defined in the KPDES No. KYR100000, latest revision. A checklist may be obtained from the Office of the City Civil Engineer. Information can also be obtained from EPA’s website.
      (2)   All items within the SWPPP shall be site specific.
      (3)   The SWPPP shall be signed and certified in accordance with the signatory requirements in 401 KAR 5:065, Section 1(11).
      (4)   A current copy of the SWPPP shall be readily available on the construction site from the date of project initiation (NOI) to the date of termination (NOT, notice of termination). The NOT shall be sent to the Kentucky Division of Water.
(Ord. 432, passed 5-16-90; Am. Ord. B2006-8, passed 5-23-06; Am. Ord. B2011-19, passed 9-27-11) Penalty, see § 156.99