In-Stream Restoration and Bioengineering Practices
Wednesday, March 7

Presented by: Prunuske Chatham, Inc., Mike Jensen
Bioengineering Associates, Evan Engber
The Bay Institute, Students and Teachers Restoring a Watershed (STRAW) Project

Learn about and tour local in-stream restoration and bioengineering projects with staff from Prunuske Chatham, Inc.; Bioengineering Associates; and The Bay Institute’s “Students and Teachers Restoring a Watershed (STRAW) Project”. This full day event will start with a slideshow of the project sites and an overview of project considerations and design details. Afterwards we will tour each project.

The first site visited will be Beringer Blass Wine Estates in Asti to see a large-river bioengineering project designed and constructed by Bioengineering Associates Inc. This project repaired 900 critical feet of eroding bank on the Russian River. The Russian River drains 1,485 square miles and is approximately 112 miles long. Over a 10 year period, the project site lost up to 300 lateral feet of streambank along several thousand feet; removing large trees and threatening vineyard roads and historical buildings. Another 80 lateral feet of bank eroded during the 2-year planning period. Construction of the bank stabilization required moving the river into a secondary channel. The eroding bank was re-sloped and then stabilized with a live willow brush mattress and three large boulder wing deflectors. Live willow siltation baffles were used to stabilize the toe of the newly shaped bank and to build a terrace. This project was completed in 2002.

Next, we will visit a stream stabilization project along a headwater tributary to the Laguna de Santa Rosa. The Laguna is a 254 square mile watershed and the second largest tributary to the Russian River. Participants will examine how a small, severely eroded stream was completely reconstructed and discuss the process from design through construction. The small stream flows through highly erodible soils and had severely incised in the last 5 years creating steep, undercut banks leading to multiply bank failures and slumps which would ultimately threaten the stability of a reservoir and create severe sedimentation in the Laguna downstream. The streambed and reservoir were stabilized by reconstructing the natural bed elevation of the stream on 10 feet of engineered fill allowing for appropriate channel geometry widths and flood-prone meadow creation. The 800 linear feet of streambed was built using boulder step pools, roughened riffles, and boulder cascades for grade controls. Streambanks and created floodplain areas were stabilized using coir blankets along with an aggressive transplanting and revegetation effort. Isolated slips and headcuts were stabilized using various bioengineering techniques including brush layering, willow wattles, straw wattles, live staking and fabric reinforced earth fills with brush layers.

Stemple Creek projects highlight restoration work completed by students in the STRAW Project in partnership with the Marin and Southern Sonoma RCDs and NRCS. The STRAW Project works with K-12 classes and technical professionals in the North Bay to restore the watersheds through action and education. Participants will visit a multi-phase riparian restoration project on 4 ranches along Stemple Creek, first started in 1993 by students working with a rancher to help the endangered freshwater shrimp (Syncaris pacifica). Stemple Creek flows west of Petaluma through family farms and ranches to the Estero de San Antonio, north of Tomales Bay. We will examine some of the revegetation and biotechnical projects completed by students and AmeriCorps volunteers and hear from STRAW staff about the successes and challenges of watershed education and restoration during the 15 year history of the program.