CA AB639

Excludes certain weirs from the legal definition of "dam" under California Water Code, exempting them from Department of Water Resources dam supervision requirements

Qualifying barriers must not impound water above the top of a levee, must maintain at least 3 feet of freeboard on the levee, and must function as a weir

Applies only to nine specifically named weirs: Peoples Weir, Reynolds Weir, Last Chance Weir, Lemoore Diversion Weir, Island Weir, Crescent Weir, Stinson Weir, Empire Weir No. 1, and Empire Weir No. 2

Defines "weir" as an agricultural water delivery structure with removable flashboards or gates that regulates stream flow and operates as part of a federal flood control system under 33 CFR Part 208