Book Description

In California's Central Valley, dams block 95 percent of historic salmonid habitat. To restore access by spring-run chinook salmon (Onocorhynchus tshawytscha) and other anadromous fish to approximately 12 miles of upstream spawning habitat on Clear Creek (drainage areas 720 km 2), the US Bureau of Reclamation removed the McCormick-Saeltzer Dam in November 2000. Previous studies -the most recent in 2004- identified significant sediment mobilization since dam removal at, and above, the former dam site. In October 2011, we resurveyed two previously established cross sections at 26 m and 103.3 m upstream of the dam site and conducted a long profile of the thalweg from the dam site to 175 m upstream. We also replicated previous site photographs, drew vegetation maps and compared 2010 aerial photographs to those from 1998 and 2004 to assess vegetation change and erosion patterns. Our results documented little incremental erosion at and upstream of the dam site since 2004, suggesting that sediment mobilization post-dam removal has largely stopped. Establishment of riparian vegetation may be stabilizing remaining sediment deposits.