"Channel migration zones (CMZ)" means the land adjacent to the current river channel that is at high risk of occupation by the channel within the next 100 years. All areas separated from the active channel by a legally existing artificial structure(s) that is publicly maintained and likely to restrain channel migration, including transportation facilities, built above or constructed to remain intact through the one hundred-year flood, shall not be considered to be in the channel migration zone. Areas behind natural or manmade features which limit channel migration that allow fish passage shall not be included in the channel migration zone. (Added by Amended Ord. 06-061, Aug. 1, 2007, Eff date Oct. 1, 2007; Amended by Amended Ord. 12-025, June 6, 2012, Eff date July 27, 2012).