BIOLOGICAL AND ECONOMIC IMPLICATIONS OF SACRAMENTO WATERSHED MANAGEMENT OPTIONS

The Sacramento River and Delta system is the most important single source of water for two-thirds of California's population and more than 7 million acres of farmland. Management of the system is divided among many local, state, and federal agencies, with significant private-sector involvement by farmers and hydroelectric utilities. In this study, economic, hydrodynamic, water-quality, and ecological models are incorporated to evaluate the costs and benefits of alternative strategies for protecting and restoring sensitive aquatic species, providing quantitative spatial and temporal assessments of the impacts of management alternatives. Each of the four modeling frameworks is described, including their linkages. Two policy scenarios are selected, representing extremes in terms of the types of policies being contemplated or implemented: a reallocation of water from federal water users to environmental purposes; and structural changes in the delta that move the location of diversions for the large pumps sending water south to the San Joaquin Valley and southern California. The scenarios are examined in light of the impacts of changes from normal or dry years on farmers' profits, cropping patterns, and water use. Results show that, while reductions in irrigation diversions and accompanying increases in river flows are substantially more effective in reducing fish mortality than other options, the option is the most costly to the agricultural sector.