Lessons learned from river restoration projects in California

Abstract

1. California is a tectonically active region with a Mediterranean climate, resulting in extreme spatial and temporal variability in river channel conditions. Restoration approaches that work in one part of the state may not succeed elsewhere. 2. Restoration projects should be planned and designed based on an understanding of geomorphological and ecological processes, rather than simply mimicry of form, as in blind application of a classification scheme. 3. Most rivers in California have been dammed, resulting in changed flow and sediment transport conditions downstream. If these changes are not recognized, restoration designs are likely to be ineffective or inappropriate. 4. Very few restoration projects in California have been subject to objective post-project evaluation. As a result, opportunities to learn from past experience to improve future project design have been lost. 5. A case study on Rush Creek illustrates the importance of geomorphologically and ecologically informed project objectives, and the need to account for dam-induced hydrologic changes in developing recommendations for flushing flows. © 1998 John Wiley & Sons, Ltd.