In 2008, Friends of the Hylebos will utilize a groundbreaking new technique to enhance East Hylebos Creek habitat and reduce downstream sedimentation. The Picket Fence design was developed by our partners at Natural Systems Design to provide a volunteer friendly way to add small woody debris to small urban streams, and encourage habitat diversity and stream aggradation in erosion prone reaches.

The Picket Fence design utilizes short stakes of dead hardwood assembled across a channel like a short picket fence. The fence traps small debris, without creating fish passage barriers. The accumulation of material encourages sediment to build up on the upstream side, and encourages pool formation on the downstream side. See the Picket Fence conceptual design (PDF).

With a Community Salmon Fund grant from King County and the National Fish & Wildlife Foundation, The Friends and Natural Systems Design will install Picket Fence structures over 2,000 feet of the East Hylebos (upstream of the West Milton Nature Preserve).

This reach currently features minimal pool habitat and channel diversity. The steep canyons of the East Hylebos Ravine are constantly eroding and provide a substantial and constant supply of sand and gravel to downstream reaches.

We anticipate the Picket Fence treatment will encourage aggradtion of the stream channel and pool formation that will provide better habitat for salmon spawning and rearing. The project should also reduce the amount of sand delivered to downstream reaches.

Contact Restoration Coordinator Hillary Kleeb to volunteer for this project