The subdivider's/developer's engineer shall be required to provide a stormwater management plan prior to final plat application submittal. The planning and zoning commission shall not recommend approval of any subdivision plat which fails to make adequate provisions for stormwater. This section shall be applicable to all subdivisions, excepting those lots, subdivisions and units of subdivisions which, on the effective date of this chapter, have infrastructure improvements installed in the subdivision or unit of a subdivision.
A. A stormwater management plan shall be required for all applicable subdivisions. It shall provide all measures necessary to maintain the post development peak discharges that are equal to or less than the respective predevelopment peak discharge rates, through stormwater management practices that control the volume, timing, and rates of flow.
B. A stormwater management plan shall accommodate for potential stormwater from any upstream drainage or sheet flow area, whether inside or outside the subdivision.
C. A stormwater management plan shall accommodate for potential stormwater effects on any subdivision or tract of land that is located downstream from the proposed subdivision.
D. Where a subdivision is traversed by a watercourse, drainageway, channel or stream, a stormwater easement or drainage right of way shall be provided that conforms to the lines of such watercourse, including adequate width for potential meandering and access for maintenance.
E. Storm drainage systems shall be separate and independent of city sewer systems.
F. A stormwater management plan that includes retention/detention areas shall be permanently maintained by the subdivider/developer, homeowners' association, or its successor in interest.
G. The retention/detention areas may be combined with open/recreational spaces and serve as dual uses. In the event a dual use is approved as a part of the development plan, the total area designated for the retention/detention of stormwater shall be maintained by the subdivider/developer, homeowners' association, or its successor in interest, and the city shall not assume ownership or maintenance responsibility.
H. All subdivision wide stormwater management areas and retention/detention areas shall be constructed without trees, shrubs or permanent structures that would interfere with maintenance requirements. The subdivider/developer shall establish the retention/detention area with native or drought resistant grasses. (Ord. 982, 11-10-2015)