King CountyDRNBASIN 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 than DRNBASIN.ArcGIS DynamicMapLayerhttps://hub.arcgis.com/datasets/477435db888e4fe0afe130c90a7c6e5f_341engPublicWatershed Boundaries Derived from Terrain Data / topo watershed area [Washington (State)--King County]Web servicesWashington (State)--King CountyWashington (State)Last Modified: 2025-11-21