No development shall cause downstream property owners, watercourses, channels or conduits to receive storm water runoff from proposed developments at a higher peak flow rate than would have resulted from the same storm event occurring over the site of the proposed development with the land in its natural, undeveloped condition. For the purposes of this chapter, “undeveloped condition” shall mean that all the natural retention areas and drainageways plus existing farm drainage tiles and highway drainage structures shall be included in the flow calculations. For the purposes of the following calculation, all ground covers shall be considered to be a meadow or grassland, with the exception that forested areas shall be treated as woodlands. “Channel” or “drainage channel” shall mean the channels used to convey the 100-year drainage flows between successive retention facilities or to retention facilities or from the property.
('69 Code, § 5-18(b)(2)) (Ord. O-83-1, passed 5-9-83)