The city shall determine the number of square feet of impervious surface in all non-single-family parcels, excluding undeveloped parcels, and the total surface area of each such parcel of real property, using the amount of impervious surface provided by the applicant, the best available source data as obtained through the records of the appropriate county assessor for the county in which the parcel is sited, aerial photographic methods, or applicable engineering drawings. Within the limits of the source data, accuracy to two-tenths of an equivalent service unit will be made. Impervious surface created incidental to a lot line adjustment to separate an undeveloped parcel from a developed parcel and which results in impervious surface less than two-tenths of an equivalent service unit upon the undeveloped parcel shall not be subject to a storm drainage charge. (Ord. 6617 § 10, 2016; Ord. 5853 § 1, 2004; Ord. 5530 § 1, 2001; Ord. 5293 § 2, 1999; Ord. 5212 § 1 (Exh. J), 1999; Ord. 4492 § 4, 1991.)