§ 152.139 DRAINAGE/GRADING STANDARDS.
   (A)   The subdivider shall consider the retention of natural storm water/snowmelt drainage patterns in the design of his or her proposed subdivision. The subdivider shall be responsible to provide adequate drainage facilitates for his or her development and upstream properties.
   (B)   All natural drainageways draining properties upstream from the subject property shall be identified and preserved, and no structures shall be less than one foot above the water level in the drainageway created by a storm of a 100-year, 24-hour rain event. No filling of areas inundated by the 100-year, 24-hour rain event shall be allowed.
   (C)   Additional runoff for a 100-year, 24-hour rain event from all streets and building sites at build-out shall be accounted for and maintained within the development.
   (D)   Natural or human-made storage areas shall be utilized where needed and shall be designated by drainage and utility easement by the subdivider. All storage areas shall be vegetated and designed to lower naturally after a storm.
   (E)   All drainage structures or improvements provided shall be sufficient in size to pass a 100-year, 24-hour storm event through the natural drainageway.
   (F)   All areas disturbed by grading, street construction or structure installation shall be covered with a minimum of three inches natural topsoil and seeded. Drainageways over 2% in gradient shall, at a minimum, be sodded.
   (G)   All parking areas, heavy use areas, storage areas and impervious area shall be diverted to a basin designed to allow entrapment of silts and nutrients prior to discharge to a natural drainageway.
   (H)   There shall be no discharge of untreated storm water to a water body.
   (I)   Erosion control measures shall be provided as needed to prevent and/or contain erosion.
(Ord. 906-2011, passed - -2011) Penalty, see § 152.999