Skip to Main Content View Text-Only

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Suite 1000, Portland, OR 97204

About the Watershed

Tryon Creek Watershed mapThe 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


Working for clean rivers and health watersheds

Heartbleed Security Notice

A serious security vulnerability known as "Heartbleed" was recently discovered in OpenSSL, a popular software library commonly used by many websites on the internet to encrypt communication between a user's computer and a web server. is NOT affected by this vulnerability as it does not use the OpenSSL software library. Please rest assured we are dedicated to protecting your security on this website.