Throughout the world, and particularly in the American West, people are learning how to remanage natural resource and environmental systems, which they had thought of as fully developed and sustainable. In many cases, the old assumptions are proving false. External forces such as sea level rise, climate change, economic globalization, population growth, and rising concern for the natural environment all impose changes on the management of these systems. In some cases, the internal dynamics, however well intentioned, are also proving unsustainable—with outcomes such as soil erosion, accumulation of pollutants in soils, and groundwater deterioration imposing changes in management over...

The modern history of the Delta reveals profound geologic and social changes that began with European settlement in the mid-nineteenth century. After 1800, the Delta evolved from a fishing, hunting, and foraging site for Native Americans (primarily Miwok and Wintun tribes), to a transportation network for explorers and settlers, to a major agrarian resource for California, and finally to the hub of the water supply system for San Joaquin Valley agriculture and Southern California and Bay Area cities. Central to these transformations was the conversion of vast areas of tidal wetlands into islands of farmland surrounded by levees. Much...

The Sacramento–San Joaquin Delta is significantly changed from its historic condition. Before the arrival of Europeans, the Delta was one of California’s most dynamic landscapes. Lying at the confluence of the Sacramento and San Joaquin rivers and their floodplains at the head of the San Francisco Estuary, with its extensive marshes and tidal channels, “equilibrium” in the Delta consisted of constant change, involving self adjustment to daily tides, annual floods and droughts, shifts in climate, and rise in sea level. As noted in Chapter 2, the policies and practices of the past 150 years have overtly or inadvertently reduced the Delta’s...

Changes in the Delta are inevitable, given the unstoppable processes of sea-level rise, land subsidence, earthquakes, and a warming climate bringing larger floods. As discussed in Chapter 3, these changes pose grave questions about future land uses in many parts of the Delta. Anticipating these changes is also critical for managing California’s water supplies, given the Delta’s central role in moving water from Northern California watersheds to farmlands and cities south and west of the Delta. Recent water exports from the Delta have ranged from 5 to 6 million acre-feet (maf) per year, supplying much of the water used in...

Since water exports began in the 1940s, the Delta has been managed to keep its water fresh enough for agricultural and urban uses by export users and in-Delta users. This management—achieved through the release of water from upstream reservoirs and changes in export schedules—can vary daily because of the Delta’s complex and dynamic physical environment. Located on the eastern edge of the San Francisco Estuary and at the mouth of two major rivers, the Delta experiences numerous influences on its water quality: in-flows of fresh water, saltwater, and drainage water, with substantial mixing from the tides. The future...

“The Delta ecosystem and a reliable water supply for California are the primary co-equal goals for a sustainable Delta.” This is the first recommendation in the long-term vision for the Delta suggested by Governor Schwarzenegger’s Blue Ribbon Task Force (Isenberg et al. 2008a). A major challenge to achieving such a balance is that ecosystem water demands are neither straightforward to gauge nor constant across or within years. Simply allocating some fixed proportion of the water for ecosystem purposes is unlikely to recover populations of desirable species,¹ as evidenced by the failure of “environmental” water provisioned over the last decade or...

The Delta is a major source of water for urban and agricultural uses in the Bay Area, the southern Central Valley, Southern California, and the Delta itself. The recent rise of water markets has more closely linked water management in upstream and importing regions of the state, and the evolving natural conditions in the Delta and modifications in export management policies will cause major changes for water users and managers throughout California. In this chapter, we estimate the costs of different approaches to managing Delta exports and outflows from the perspectives of both water supply and quality. Although there is...

To increase the chances of favorable ecosystem and economic outcomes, California needs a policymaking environment that enables decision makers to anticipate the changes facing the Delta. This requires effective political leadership, a sound governance and finance system, and an appropriate set of regulatory tools.

Given the many often-conflicting stakeholders concerned with Delta outcomes, there is no substitute for higher-level political leadership to help chart a new course for Delta management and negotiate solutions for some of the difficult trade-offs among human users of the Delta’s resources. Mitigation offers a promising path for resolving some of these trade-offs, while fostering policies...

The Delta poses a variety of highly complex problems with a myriad of uncertainties. These troublesome characteristics are common to many other problems, ranging from public policy issues such as national defense and school system planning to personal career and retirement planning. To address all aspects of such problems simultaneously is beyond human abilities and comprehension. To solve complex problems, it is first necessary to organize them into smaller components that can be understood and solved sequentially, to provide insights into how to solve other pieces and to indicate promising overall strategies.

In this chapter, we organize recent scientific and...

To be successful, natural resources management must be able to adapt to changing conditions. This book has looked at the long-term management of California’s Sacramento–San Joaquin Delta, which faces inevitable changes in landscape, economy, and ecology, driven by sea-level rise, climate change, earthquakes, land subsidence, and biological invasions. Management objectives for this region have also been changing over time, as a consequence of long-term shifts in the societal values placed on the Delta’s ecosystem and the species that depend on it to thrive. Now we summarize our conclusions regarding the Delta’s changing landscape, the potential for improving the Delta’s...