Description: Basins 6-digit Hydrologic Unit Code (HUC) Watershed Boundary Dataset (WBD) for Orange County, California. The Watershed Boundary Dataset (WBD) is a comprehensive aggregated collection of hydrologic unit data consistent with the national criteria for delineation and resolution. It defines the areal extent of surface water drainage to a point except in coastal or lake front areas where there could be multiple outlets as stated by the "Federal Standards and Procedures for the National Watershed Boundary Dataset (WBD)" “Standard” (http://pubs.usgs.gov/tm/11/a3/). This dataset represents the hydrologic unit boundaries to the 12-digit (6th level) for the entire United States. At a minimum, the HUs are delineated at 1:24,000-scale in the conterminous United States, meeting the National Map Accuracy Standards (NMAS). Higher resolution boundaries are being developed where partners and data exist and will be incorporated back into the WBD. WBD data are delivered as a dataset of polygons and corresponding lines that define the boundary of the polygon. WBD polygon attributes include hydrologic unit codes (HUC), size (in the form of acres and square kilometers), name, downstream hydrologic unit code, type of watershed, non-contributing areas, and flow modifications. The HUC describes where the unit is in the country and the level of the unit. WBD line attributes contain the highest level of hydrologic unit for each boundary, line source information and flow modifications.
Copyright Text: Dr. Kostas Alexandridis, GISP, Data Scientist, OC Public Works, OC Survey Geospatial Services for the Orange County WBD project processing. Original data source: USGS National Watershed Boundary Dataset (WBD) accessed from the ESRI WBD Living Atlas Feature Service. Funding for the Watershed Boundary Dataset (WBD) was provided by the USDA-NRCS, USGS and EPA along with other federal, state and local agencies. Representatives from many agencies contributed a substantial amount of time and salary towards quality review and updating of the dataset in order to meet the WBD Standards. Acknowledgment of the originating agencies would be appreciated in products derived from these data. See dataset specific metadata for further information.