USGS science at work in the San Francisco Bay and Sacramento-San Joaquin Delta estuary

Covering more than 1,600 square miles, the San Francisco Bay and Sacramento-San Joaquin Delta together form the largest estuary on the west coast of the Americas.The "Bay-Delta" is home to nearly 10 million people and is valued for its beauty, Mediterranean climate, and recreational opportunities.The estuary is also home to a diverse community of plants and animals and is the hub of California's freshwater-delivery system to move water from the north to the southern part of the State.It drains a watershed of more than 75,000 square miles that covers more than 40 percent of California.This system is a source of water for more than 25 million Californians and more than 4 million acres of farmland in the Sacramento-San Joaquin (Central) Valley.The U.S. Geological Survey (USGS) works in close cooperation with scientists and managers from Federal, State, and local agencies; academia; and the general public to ensure that objective and credible science is available to the decision-making processes for management of the Bay-Delta.USGS research and data collection efforts in the region are funded from a wide variety of Mount Diablo during sunrise over the Sacramento-San Joaquin Delta.Inset shows a Great Egret (Ardea alba) standing in the shallows of the Delta.(U.S. Geological Survey photos by Francis Parchaso.)sources, and the results are used by State and Federal regulatory and management agencies, stakeholders, and the public.Currently, USGS scientists are working on more than 90 research studies in the Bay-Delta.