Dam Removal & Stream Restoration, Dominici Creek, La Grange, California

Client: French Bar Bluffs LLC and California Regional Water Quality Control Board

Dominici Creek is a tributary to the Tuolummne River, East of Modesto California. Eight large compacted earth dams were constructed on private lands in 2006 without permits or engineering by the developer. The dams averaged approximately 100 feet across and 40 feet high, and were built in rather steep canyon topography. A major rain event during the Spring of 2006 caused three of the dams to fail which released thousands of cubic yards of silt and sands which flowed into the Tuolummne River, an important salmon and steelhead stream. In addition, the rapid draw-down of the former pools caused massive slumping and bank failure along the canyon walls. A cleanup and abatement order was issued to the developer by the Central Valley Regional Water Control Board (RWQCB) in Sacramento.

Northwest Biological Consulting provided designs and obtained regulatory approvals to remove all of the 8 dams and restore the channel and stream to a stable condition. Approximately 3 miles of channel within two separate forks comprised the project area. NBC restoration crews and heavy equipment operators spent most of the summer of 2006 removing the remnants of the 3 failed dams and we also removed the remaining 5 intact dams. Over 70,000 cubic yards of dam and eroded bank material was either removed to the original borrow sites or utilized to shape and contour the channel morphology. Large boulders and oak logs from the previously removed trees were utilized to stabilize many of the bank failures. Old photographs and previous topographic survey data was used as a template to guide the channel restoration and bank configuration. Riparian and wetland plants were planted within the wetland and riparian margins of the project area.

The restoration project was completed by October of 2006 and the entire project was inspected and signed-off by the RWQCB. The Cleanup and Abatement Order was satisfied by a ruling in Stanislaw County Superior Court.