(a) Performance Standard. In order to achieve the goals and purposes of this chapter, the following performance standard for storm water control facilities will be used: The goal of this performance standard is to preserve the natural condition of water bodies included in and adjacent to the Village, in whole or in part. Within the Village of Dimondale, unless otherwise approved, storm water runoff shall be conveyed via natural drainage systems such as swales and vegetated buffer strips. When site conditions permit, infiltration of storm water runoff is strongly recommended. Storm water managed in this way provides greater protection for surface water quality, and also assists in augmenting stream base flow, reduction of flash storm flows and prevention of stream bank erosion. Section 1050.14(b) specifies design criteria, in order that the volume and rate of storm water runoff are controlled at predevelopment levels.
(b) Design Standards. The design standards for storm water runoff facilities, are the following:
Design Standards | Use BMPs and site design techniques such as those found in the most current edition of the SEMCOG Low Impact Design Manual, the Best Management Practices for Michigan Watersheds published by the State of Michigan, design standards adopted by the Dimondale Village Council or equivalent design literature to achieve the following. |
Water Quality Control | Treat the first 1" of runoff from the contributing watershed such that a minimum of 80 percent removal of suspended solids is achieved. |
Bank Erosion Control | Control storm runoff such that there is no net increase in runoff volume or rate from all storm events up to the two-year, 24-hour event from the conditions existing prior to the development. |
Flood Control | Contain storm water runoff such that there is no net increase in runoff volume or rate from the conditions existing prior to the proposed development onto any adjacent property in a one hundred year storm event. Detain with infiltration when conditions permit. Limit rate of release to 0.13 cfs/acre per ECDC rules. |
(Ord. 2011-4. Passed 8-8-11.)