Washington State Puget Sound PartnershipActive channel hydrography (referred to as open channel or bank-to-bank polygon in the State and Tribal Riparian Monitoring and Adaptive Management Recommendations ) is defined as an approximation of the active channel width of a stream determined using remote sensing methods, e.g. lidar, and is inclusive of gravel and cobble bars and the wetted portion of the stream. The active channel is analogous to the "bankfull channel" (Leopold and Maddock 1953, Leopold et al 1964, Williams 1978) or the ordinary high-water mark line (WAC 220-660-030(111), where the presence and action of waters are "so common and usual, and so long continued in ordinary years as to mark upon the soil or vegetation a character distinct from the abutting upland," and along freshwater where this line cannot the delineated the ordinary high water line is the elevation of the mean annual flood for every three years. The intent for these data is to identify the edge of the stream riparian, i.e., where woody vegetation begins, for riparian and ecosystem monitoring. Methods document is available for download at https://wa-psp.maps.arcgis.com/sharing/rest/content/items/ef23b0e8c4ca48feac8c46c0f6d697b1/data Scripts and the spatial data framework to generate active channels are available at the Puget Sound Partnership Spatial Hub https://data-wa-psp.hub.arcgis.com/content/a3b36a7ba14e4670851503d7eb7f0e4e/aboutArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/2ef1125c38ff443e99ce221496648528_0engState of Washington Geospatial Open Data PortalPublicWA PSP Active Channel WRIA 1 Nooksack [Washington (State)]Web servicesWashington (State)Last Modified: 2025-12-19