20221212 15202500 1.0 TRUE SDE4Caltrans.SDE.BNDY_RegionalBoards The boundaries of the 9 California Regional Water Quality Control Boards are derived from watershed boundaries in the The California Watershed Map (CALWATER version 2.2). Calwater 2.2 is a set of standardized watershed boundaries meeting standardized delineation criteria. California State Water Resource Control Board, Tierra Data Systems