Two Decades of River Restoration in California: What Can We Learn? G. M. Kondolf, 1 S. Anderson, 2,3 R. Lave, 4 L. Pagano, 1 A. Merenlender, 4 and E. S. Bernhardt 5 Abstract As part of the National River Restoration Science Synthe- sis (NRRSS), we developed a summary database of 4,023 stream restoration projects built in California since 1980, from which we randomly selected 44 records for in-depth interviews with project managers. Despite substantial difficulties in gathering the data, we were able to draw conclusions about current design, implementation, moni- toring, and evaluation practices used in California projects and compare them with national trends. Although more than half of the projects for which we conducted inter- views were located in watersheds for which a management or assessment plan had been prepared, these plans had a limited impact on site selection. We also found that the state lacks a consistent framework for design, monitoring, and reporting restoration projects, and that although moni- toring is far more widespread than the information in the NRRSS summary database would suggest, there are still problems with the type, duration, and reporting of moni- toring. The general lack of systematic, objective assess- ment of completed projects hinders the advance of restoration science. Key words: California, case studies, database, evaluation, monitoring, National River Restoration Science Synthesis restoration, restoration planning, river, survey. Introduction As the number of river restoration projects in North America continues to grow, the Pacific coast has the larg- est number of projects and greatest investment overall, and California continues to be one of the most active areas for river restoration (Bernhardt et al. 2005). Restoration projects in the state span a wide range, from salmonid hab- itat enhancement projects (undertaken in the state since the 1930s), abundant riparian restoration projects through- out the past three decades, to more recent efforts to restore fluvial processes by modifying dam releases and augmenting sediment supply. Despite its substantial num- ber of restoration projects, California does not have a com- prehensive catalog of restoration efforts that is easily accessible by scientists, public agencies, and community groups, although database managers at state agencies are working toward this goal (e.g., California Department of Fish and Game, Information Center for the Environment). The effectiveness of the restoration investment has been largely unevaluated (cf Kleinschmidt Associates 2003). Such evaluation is essential as feedback to the adaptive management approach embraced by institutions, such as the CALFED Bay-Delta Ecosystem Restoration Program, the largest single funder of restoration in the state, with an investment over $500 million in restoration projects from 1996 to 2005. California’s distinct Mediterranean climate may render river restoration approaches adopted elsewhere unsuitable (Kondolf 1998). Thus, a review of res- toration projects undertaken in California to date is timely and can potentially inform future restoration efforts. We conducted this study as part of a national effort, the National River Restoration Science Synthesis (NRRSS), using methods consistent with our NRRSS colleagues elsewhere, so that our data would contribute to a national assessment and the California results could be informed by the larger, national context (Bernhardt et al. 2007). The objectives of the study were to compile a database of restoration projects undertaken in California through 2003, and to conduct follow-up interviews with imple- menters of randomly selected projects. We sought to understand the type and extent of river restoration pro- jects undertaken in the state and to gather more detailed information about current design, implementation, moni- toring, and evaluation practices used in California projects to inform and improve future practice. Methods Detailed descriptions of database design and our data syn- thesis effort are available in supplemental online material to Bernhardt et al. 2005 and at our Web site: http://www. restoringrivers.org/NRRSS_Process. Here, we provide a succinct description of our methods. 1 Department of Landscape Architecture and Environmental Planning, University of California at Berkeley, 202 Wurster Hall, Berkeley, CA 94720, U.S.A. 2 Center for Environmental Design Research, University of California at Berkeley, 390 Wurster Hall, Berkeley, CA 94720, U.S.A. 3 Address correspondence to Shannah Anderson, email shannah@berkeley.edu 4 Department of Environmental Policy, Science & Management, University of California at Berkeley, 137 Mulford Hall #3114, Berkeley, CA 94720, U.S.A. 5 Department of Biology, Duke University, Durham, North Carolina 27708, U.S.A. Ó 2007 Society for Ecological Restoration International 516 Restoration Ecology Vol. 15, No. 3, pp. 516–523 SEPTEMBER 2007