The subdivider shall consider the retention of natural stormwater/snowmelt drainage patterns in the design of his or her proposed subdivision. The subdivider shall be responsible to provide adequate drainage facilities for this development and upstream properties.
(A) All subdivisions shall demonstrate provisions for adequate surface or subsurface runoff of stormwater and snow melt directed to natural drainage ways.
(B) All natural drainage ways 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 drainage way 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 drainage way.
(F) All areas disturbed by grading, street construction, or structure installation shall be covered with a minimum of three inches natural topsoil and seeded. Drainage ways 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 drainage way.
(H) There shall be no discharge of untreated stormwater to a water body.
(I) Erosion control measures shall be provided as needed to prevent and/or contain erosion.
(Ord. passed 4-10-2017) Penalty, see § 150.999