Washington State Department of Natural ResourcesAs established by WAC 222-22-020, the state is divided into areas known as watershed administrative units (WAUs). WAU boundaries are defined by the Department of Natural Resources (DNR) in cooperation with the departments of Ecology, Fish and Wildlife, affected Indian tribes, local governments, forest land owners, and the public. This dataset is intended for use at 1:24,000 scale. WAU's are used by the Timber/Fish/Wildlife cooperators as the boundaries for watershed analysis studies and other natural resources management purposes on state and privately owned lands. WAU represents the administrative boundaries of 846 units. The boundaries are mainly along drainage divides (ridges), with some along rivers and other Washington State Department of Natural Resources (DNR) management boundaries. In the forested areas of the state WAUs range in size from 3,822 to 297,614 acres with a mean of 40,187 acres and a standard deviation of 26,697 acres. On the Columbia Plateau WAU areas range in size from 35,098 to 1,765,555 acres. This version of the WAU boundaries is current as of April 2006. Administrative boundaries based on hydrology form a general hierarchy. Water Resource Inventory Areas (WRIAs) are the largest unit, BASINs are subunits of WRIAs, and WAUs are subunits of BASINs. However, boundaries in this hierarchy do not necessarliy match in all areas. Where watershed analysis was been conducted, WAU boundaries may cross WRIA lines. Do not use WAU to derive WRIA boundaries. WRIA is managed and maintained by the Washington Department of Ecology.ArcGIS DynamicMapLayerhttps://hub.arcgis.com/datasets/d8d2aeaa4cb24cca92b708b7ba086279_0engState of Washington Geospatial Open Data PortalPublicWatershed Administrative Units - Forest Practices Regulation [Washington (State)]Web servicesWashington (State)Last Modified: 2021-01-07