1120 SW 5th Avenue, Room 1000, Portland, OR 97204
The Willamette Plan Area is divided into 27 subwatersheds, drainage areas of only a few square miles or less. Their smaller size makes subwatersheds easier to map and assess for restoration potential. Since every part of Portland is in a subwatershed, everyone can help improve the health of the Willamette River by working in their own neighborhood.
Detailed information about the subwatersheds, along with four Willamette River segments is compiled in the Characterization Report under six categories: Habitat and Biological Communities, Infrastructure, Land Use and Population, Landscape and Hydrology, Stewardship, and Water Quality.