WRIA vs Watershed Subbasin

It is important to note that Water Resource Inventory Areas (WRIA) should not be used for hydrological analysis of river systems.  For an accurate view of river watersheds based on topography, use the Watershed Boundary Subbasin layer instead.  Although most boundaries are similar, differences are observed along the Canadian border, in the Skagit area, and throughout the Puget Sound main basin. This map displays WRIAs as pink boundary lines over shaded sub-basins.

Map Creation Date: 
Wednesday, May 16, 2012