Californians today seem willing to make sacrifices to protect the environment, including paying more \textemdash directly or indirectly \textemdash for water. There are limits to this willingness, however, and these limits are determined by a combination of underlying value systems and the perceived relationships between costs and benefits. A number of interrelated values, economic and noneconomic, can be invoked to justify devoting water to the protection of fish and other aquatic life. These values can be incorporated into strategies for protecting natural systems, ranging from protecting species to managing large ecosystems. The application of multiple and often conflicting values lies at the heart of CALFED, a multiagency effort to provide assured water supplies to farms and urban areas while also protecting and enhancing aquatic species and habitats. The CALFED Strategic Plan for Eco-system Restoration for the San Francisco Bay-Delta ecosystem is an example of the kind of broad-based strategy that must be implemented if we are sincere about maintaining natural systems for the benefit of humans and the rest of California\textquoterights biota in the 21st century and beyond.