This chapter describes advances during the past decade in understanding flow dynamics and how water-quality constituents, such as salinity, heat, oxygen, nutrients, contaminants, and more, move within California’s Sacramento-San Joaquin River Delta. Water-quality constituents are affected by water diversions and other human manipulations of flow and they greatly affect the quantity and quality of habitats in the Delta.
Along with human intervention, the Pacific Ocean, the Central Valley watershed, and the atmosphere, are a few drivers of flow and transport in the Delta. These drivers provide a conceptual framework for presenting recent findings. The tremendous expansion of acoustic and optical instruments utilized in the Delta over the past decade has greatly improved our understanding of how tidal variability affects flow and transport. Sediment is increasingly viewed as a diminishing resource needed to sustain habitat and tidal marsh, especially as sea level rises.
Connections between the watershed, Delta, and San Francisco Bay that have been studied recently highlight that a landscape view of this system is needed rather than consideration of each region individually. Interactions of multiple drivers and information gaps are discussed.