"Threshold discharge area (TDA)" means an area within a project site draining to a single natural discharge location or multiple natural discharge locations that combine within one-quarter mile downstream as determined by the shortest flow path. (Refer to diagrams in Drainage Manual, Volume I, Glossary). (Added by Amended Ord. 10-026, June 9, 2010, Eff date Sept. 30, 2010; Amended by Amended Ord. 21-025, June 16, 2021, Eff date July 1, 2021).