(A) General.
(1) When possible, existing natural drainage ways, wetlands, and vegetated soil surfaces must be used to convey, store, filter, and retain stormwater runoff before discharge to public waters.
(2) Development must be planned and conducted in a manner that will minimize the extent of disturbed areas, runoff velocities, erosion potential, and reduce and delay runoff volumes. Disturbed areas must be stabilized and protected as soon as possible, and facilities and methods used to retain sediment on the site.
(3) When development density, topographic features, and soil and vegetation conditions are not sufficient to adequately handle stormwater runoff using natural features and vegetation, various types of constructed facilities such as diversions, settling basins, skimming devices, dikes, waterways, and ponds must be used. Preference must be given to designs using surface drainage, vegetation, and infiltration rather than buried pipes and human-made materials and facilities.
(B) Natural drainage. All development shall provide for the continuance of natural drainage ways, and structures shall be so constructed as to be one foot above the water level in the drainage way created by a storm of a 100-year return period or a 1% chance of occurrence.
(C) Drainage storage areas. The use of natural or human-made stormwater storage areas is encouraged. These areas should be vegetated and designed to naturally lower after a storm.
(D) Filling. No filling of areas inundated by the 100-year, 24-hour storm along drainage ways shall be allowed, except by conditional use permit.
(E) Impervious areas. All parking areas, heavy soil areas, storage areas, and impervious areas shall be designed to allow entrapment of silts and nutrients prior to discharge to a natural drainage way or public water.
(F) Public waters. Newly constructed stormwater outfalls to public waters must provide for filtering or settling of suspended solids and skimming of surface debris before discharge.
(G) Erosion. Erosion control measures shall be provided in all areas disturbed during any grading or construction. All areas disturbed shall be covered with topsoils and seeded. Areas subject to concentrated runoff or steeper than three-to-one shall be sodded, planted with appropriate deep-rooted vegetation, or protected with an appropriate mulch cover as directed by the City Engineer.
(Ord. passed 4-10-2017) Penalty, see § 150.999