A Recipe for River Recovery?

Efforts to restore rivers damaged by diversion of their waters to agriculture and cities have mostly focused on optimizing habitats for a single fish species, such as the salmon. But plans proposed for Northern California's Trinity River and the streams feeding Mono Lake, also in California, take a more radical tack: They aim to restore the physical processes, including floods, that help a river shape its banks and bottoms. Proponents maintain that restoring natural habitats will also restore fisheries. The idea is controversial, however. The higher flows needed will take water away from agricultural and urban users, and even some ecologists question whether the approach will indeed increase fish numbers. The dispute is far from academic, for the Trinity River and Mono Lake projects may well provide models for restoration of other damaged rivers.