In making a determination as to the adequacy of drainage the chief engineer shall consider topographic conditions, rainfall, runoff, land use, depth and width of drainage channels, size of other drainage facilities, and past history of flooding, including the extent of flooding.
(Sec. 16-6.4, R.O. 1978 (1983 Ed.)) (1990 Code, Ch. 14, Art. 12, § 14-12.4)