§ 22-409. Stormwater Management.
   1.   General Requirements.
      A.   An erosion and sediment pollution control plan shall be submitted for all land development in order to promote erosion control and site stabilization during and after the construction phase. Logging operations shall be included in this requirement.
      B.   A stormwater management plan to promote long term erosion control shall be submitted for land development involving:
         (1)   Sites with slopes which exceed 8%.
         (2)   Sites with sinkholes or which are sinkhole prone.
         (3)   Sites where poor drainage or stormwater runoff problems are known to occur.
         (4)   Mobile home parks and multi-family residential developments.
         (5)   Commercial and industrial developments.
      C.   The Planning Commission shall request that the Clinton County Conservation District review and comment on stormwater management plans.
      D.   All subdivision and land development proposals shall meet the requirements of the Fishing Creek watershed stormwater management plan in effect or hereinafter adopted. If conflicts emerge between this Chapter and the watershed stormwater management plan, the more strict provisions shall apply.
      E.   The requirements contained in this § 22-409 shall apply to all areas of Lamar Township not located in the Fishing Creek/Cedar Run Watershed. Those areas located within the Fishing Creek/Cedar Run Watershed shall be governed by the Fishing Creek/Cedar Run Watershed Stormwater Management Ordinance [Chapter 26] enacted by the Board of Supervisors of the Township of Lamar on November 11, 1996. [Ord. 54-5-96A]
   2.   Plan Requirements.
      A.   Subdivisions and land developments adjacent to streams must comply with § 22-413 "Stream Corridors."
      B.   The erosion and sediment pollution control plan shall be prepared by the subdivider or a knowledgeable designee who shall consider the potential for accelerated soil erosion resulting from development activities. Soil erosion and sedimentation control measures shall be designed to protect existing vegetation and minimize the area and time of soil exposure. The plan must comply with the most recent DEP regulations and/or guidelines for soil erosion and sedimentation control in effect. [Ord. 12/10/2001]
      C.   The stormwater management plan for the proposed subdivision shall include a brief description of:
         (1)   Existing drainage patterns and stormwater runoff characteristics of the site, including any drainage or stormwater problems and facilities. Existing conditions shall be calculated for the site in its natural wooded or meadow state.
         (2)   The anticipated impact that future development of the property will have on existing stormwater runoff and drainage patterns, both onsite and offsite. Sediment leaving the site shall be indicated.
         (3)   The type of structural and nonstructural improvements planned to control post development stormwater runoff.
         (4)   The proposed location of structural and nonstructural improvements shall be shown on the plot plan. The Planning Commission shall also require the subdivider to include on the plot plan topographic contours at 2 foot intervals in order to better evaluate the proposed stormwater control techniques.
         (5)   Detailed specifications, including dimensions, typical cross-sections and profiles, shall be submitted for all structural stormwater control improvements, such as swales, seepage pits and retention and detention basins.
      D.   The stormwater management plan shall include a proposal for ownership and maintenance of all stormwater control improvements as follows:
         (1)   Where the developer proposes to dedicate such improvements to the municipality, a deed which dedicates the land to be used for stormwater control improvements to the Township shall be recorded with the final plan. A copy of the deed and a letter from the Township stating their intent to accept ownership and maintenance responsibility shall be submitted with the subdivision plan.
         (2)   Alternatively, an ownership and maintenance agreement, which specifies ownership and assigns maintenance responsibility for the proposed improvements to either the developer or among property owners within the subdivision, shall be recorded with the final plan and referenced in the deeds to each property within the subdivision.
         (3)   Where a subdivision or development is traversed or bounded by a stream or other drainage way, the developer must provide a drainage easement to preserve the unimpeded flow of natural drainage.
   3.   Design Standards.
      A.   Stormwater shall not be discharged into sinkholes.
      B.   Protection of existing vegetation shall be a key component of the stormwater management design. The site plan shall feature retention of existing vegetation to the greatest extent possible and improvement of existing vegetation where necessary.
      C.   Stormwater management controls shall be designed so that the peak rate of runoff during and after construction shall be no greater than the peak rate of runoff prior to development.
      D.   Controls and improvements shall slow the rate of runoff. Such improvements may include, but are not limited to, deed covenants which restrict the allowable impervious area on each lot, the provision of drainage easements, parabolic swales, seepage pits and detention and retention basins.
      E.   Specifications for proposed stormwater improvements shall be evaluated by the Planning Commission, in consultation with the County Conservation District or Township Engineer, on a case by case basis.
(Ord. 3/9/1993A, § 408; as amended by Ord. 54-5-96A, 11/11/1996, § 1; and by Ord. 12/10/2001)