Hydrologic Unit Boundaries, 4th field sub-basin, Portland Metro Region, Oregon

This geospatial dataset is a hydrologic unit boundary layer for the Sub-basin (8-digit) level. The dataset is a subset of the 4th level (8-digit) hydrologic unit boundaries of the Watershed Boundary Dataset (WBD) layer for Oregon. It was created by dissolving boundaries from the finer resolution hydrologic units (those of the 5th or 10-digit level) to create these broader boundaries. Boundaries within the this data set were delineated by Pacific Northwest (PNW) Hydrography Framework Partners and Natural Resources Conservation Service (NRCS) to meet state requirements and to contribute to the national WBD repository. To meet these goals, the WBD must adhere to the "Federal Standards for Delineation of Hydrologic Unit Boundaries", dated October, 2004. These boundaries were made from the Oregon and Washington datasets that have been nationally certified by Natural Resources Conservation Service (NRCS) Prior to submission the dataset was subjected to an iterative review and edit process to ensure that the hydrologic boundaries fully satisfy the federal standards. This work was completed under a Memorandum of Understanding between the Pacific Northwest Hydrography Framework Partnership, NRCS and the US Geological Survey (USGS). The current dataset includes the entire 4th level (8-digit) subbasins that fall within or the four county Metro region. This data was originally downloaded from the PNW Hydrography Framework Clearinghouse (http://hydro.reo.gov/hu.html).

Downloaded from Metro's RLIS Discovery site 7/2/2012.