WRIA boundaries derived from terrain data

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.如需了解该图层的更多信息，请查阅地理信息系统（Geographic Information System, GIS）数据目录。 流域资源清查区（Watershed Resource Inventory Area, WRIA）规划单元是依据《华盛顿州行政法典》（Washington Administrative Code, WAC 173-500）设立的。环境管护工作的规划与实施，在《华盛顿州修订法典》（Revised Code of Washington State, RCW 90.82）中已有明确规范。 WRIA的划定通常以覆盖华盛顿州内大型流域为原则。例如，WRIA 9涵盖格林-杜瓦米什河流域以及该流域西侧毗邻普吉特湾的近岸水域。WRIA 8则包含大华盛顿湖流域及其相邻的普吉特湾近岸陆地。因此，这类规划单元是由若干河流流域以及直接汇入普吉特湾的小型支流区域共同组成的复合汇水区域。 上述WRIA边界已通过数字高程模型（Digital Elevation Model, DEM）完成修订。