Lake Oswego Watershed Council

The Oswego Lake Watershed Council (OLWC) is a locally organized, non-profit, non-regulatory watershed stewardship organization established to improve the condition and health of the Oswego Lake watershed and its stream network.

MLK Days of Service

On Martin Luther King Jr. weekend 2020, Oswego Lake Watershed Council will be honoring MLK Jr’s legacy with two days of service! 

We are hosting

  • a planting event on Saturday, January 18th and
  • an ivy pull on Monday, January 20th.

You Can Help

You can help protect watershed health! Volunteer to plant trees, clear invasive weeds, sign up for our newsletter, host a presentation, or attend a free workshop.

Support the OLWC Hallinan Fund

The Coalition for Hallinan Woods Nature Park is a neighborhood organization working to preserve and expand a nature park adjacent to Hallinan Elementary School. We are partnering with Oswego Lake Watershed Council (OLWC) to raise funds in support of Hallinan Woods

Oswego Lake Tree Summit

Let’s Branch Out and
Talk Trees Together!

The Tree Summit is in partnership with the Oswego Lake Watershed Council, the Lake Oswego Sustainability Network, the Mountain Park Homeowners’ Association, and 14 neighborhood associations.


Weed of the Month: English Ivy

English ivy (Hedera helix) may conjure up images of cozy, country cottages, but don’t be deceived. This invasive weed can destroy buildings, poison pets, and topple trees.​


Resources for Residents

Be a part of the solution. There are many ways to help protect watershed health at home.

The links on this page provide useful information to help you improve water quality and wildlife habitat in your yard and your community.



Watershed Councils work with our community members, building a sense of place while together stewarding the land and water. This giving season, we’re collaborating to encourage each of you to connect with the Portland Metro area Watershed Councils where you live, work, and play!