This spring, SWWD is undertaking a project to stabilize the stream channel between the Ravine Lake outlet and Highway 61.
This project will address the erosion that this channel has seen over the past decade. The project will:
- Repair erosion
- Create structures that control flow and prevent future erosion
- Re-establish native vegetation throughout the stream
To complete this project, tree clearing is necessary. Tree clearing will occur in February 2026, followed by construction later this spring. This project takes place within the Cottage Grove Ravine Regional Park boundary. Visitors to the park should expect minimal impact.
Channel Stabilization
The observation of geomorphic changes to the channel and signs of headcutting prompted the project. Headcutting is a form of abrupt, vertical erosion to a streambank.
The use of cross vanes, U-shaped rock barriers that span the width of the stream throughout the stream, will stabilize flow in the channel. Additionally, cross vanes create aquatic habitat and support shoreline vegetation and soil structures.
Past Work
The Ravine Park Project began in 2018 to change the entrance and construct a new outlet for Ravine Lake. This addressed seasonal flooding that blocked the only entry and exit to the park.
The new outlet raised the road with a box culvert and added a 1-foot raise of the lake’s normal water level (NWL). It also increased the outlet size, from a 18 inch circular metal pipe outlet to a 6-foot by 8-foot box culvert outlet. The new outlet maintains flow speeds during 2-year, 10-year, and 100-year flooding events.