King CountyFor more information about this layer please see the GIS Data Catalog . DRNBASIN is replaced with a higher detail TOPO_CATCHMENT. The difference between the two is DRNBASIN was digitized from existing paper maps based on USGS quad maps in the early 1990s. While the TOPO_CATCHMENT was produced using Arc/Info GRID Watershed commands on 6 foot cell GRIDS built from LIDAR ascii ground model data. Topo_Catchment is higher in accuracy then DRNBASINArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/b5b9ee06328a4ce4a87de8f6d096e065_0engKing County GIS Open DataPublicWatershed boundaries derived from terrain data - King County only [Washington (State)--King County]Web servicesWashington (State)--King CountyWashington (State)Last Modified: 2025-07-30