The Tryon Creek Watershed in southwest Portland covers over 4,000 acres. About 3,000 acres are in the Portland city limits. Tryon Creek flows southeast for about seven miles from its headwaters near Multnomah Village to its confluence with the Willamette River inLake Oswego.

There are steep slopes throughout the watershed with predominant sandy loam soils. Major transportation corridors contribute to the large impervious surface area and fragment stream connectivity. The abundant forested areas consist of native plants as well as invasive vegetation.

The Tryon Creek Watershed provides important habitat to fish, birds, and other wildlife.

• Watershed area is 4,142 acres (3,058 is withinPortland’s city limits)
• 55% of the watershed is zoned single-family residential
• About 870 acres, or 21% of the watershed, is parks or open space
• About 24 % designated within environmental protection and conservation zones
• There are 27 miles of open stream channel and 3 miles in culverts or pipes
• Impervious surfaces comprise about 990 acres, or 24%, of the watershed