Watershed boundaries derived from terrain data - King County only

For more information about this layer please see the GIS Data Catalog. Watershed Resource Inventory Area. WRIA planning units were established under Washington Administrative Code (WAC 173-500). Planning and implementation of environmental stewardships are codified in Revised Code of Washington State (RCW 90.82). WRIAs are generally delineated to capture large watersheds in Washington State. For example WRIA 9 includes The Green/Duwamish River basins and Puget sound nearshores west of the watershed. WRIA 8 include the Greater Lake Washington watershed and it’s adjacent Puget sound nearshore lands. Hence they are a composite of watershed drainage areas that include a river basin(s) and also small tributary areas that directly drain to the Puget sound. These WRIA boundaries were revised using digital elevation models.