Fish Passage Site Watersheds

For more information about this layer please see the GIS Data Catalog. King County fish passage barrier prioritization scoring and Level B assessment data processing requires site-specific drainage basins. This dataset includes the area of land where precipitation collects and drains to a particular site. These drainage areas are used to calculate a variety of prioritization metrics, including percent impervious and forest land cover, count and density of upstream barriers, plus sum of upstream stream length and IP score. For sites where a Level B assessment was performed, the drainage area is used to calculate the low and high flow exceedence flows required to determine if a site is a barrier.