The Central Valley is a broad, elongated, flat valley that dominates the interior of California. It is 40–60 mi (60–100 km) wide and runs approximately 450 mi (720 km) from north-northwest to south-southeast, inland from and parallel to the Pacific coast of the state. It covers approximately 18,000 sq mi (47,000 km2), about 11% of California's land area. The valley is bounded by the Coast Ranges to the west and the Sierra Nevada to the east.
The San Joaquin River is the longest river of Central California. The 366-mile (589 km) long river starts in the high Sierra Nevada, and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suisun Bay, San Francisco Bay, and the Pacific Ocean. An important source of irrigation water as well as a wildlife corridor, the San Joaquin is among the most heavily dammed and diverted of California's rivers.
The Carquinez Strait is a narrow tidal strait located in the Bay Area of Northern California, United States. It is part of the tidal estuary of the Sacramento and the San Joaquin rivers as they drain into the San Francisco Bay. The strait is eight miles (13 km) long and connects Suisun Bay, which receives the waters of the combined rivers, with San Pablo Bay, a northern extension of the San Francisco Bay.
The Sacramento–San Joaquin River Delta, or California Delta, is an expansive inland river delta and estuary in Northern California. The Delta is formed at the western edge of the Central Valley by the confluence of the Sacramento and San Joaquin rivers and lies just east of where the rivers enter Suisun Bay, which flows into San Francisco Bay, then the Pacific Ocean via San Pablo Bay. The Delta is recognized for protection by the California Bays and Estuaries Policy. Sacramento–San Joaquin Delta was designated a National Heritage Area on March 12, 2019. The city of Stockton is located on the San Joaquin River at the eastern edge of the delta. The total area of the Delta, including both land and water, is about 1,100 square miles (2,800 km2). Its population is around 500,000.
The delta smelt is an endangered slender-bodied smelt, about 5 to 7 cm long, in the family Osmeridae. Endemic to the upper Sacramento-San Joaquin Estuary of California, it mainly inhabits the freshwater-saltwater mixing zone of the estuary, except during its spawning season, when it migrates upstream to fresh water following winter "first flush" flow events. It functions as an indicator species for the overall health of the Delta's ecosystem.
Located in northern California, the Suisun Marsh has been referred to as the largest brackish water marsh on west coast of the United States of America. The marsh land is part of a tidal estuary, and subject to tidal ebb and flood. The marsh is home to many species of birds and other wildlife, and is formed by the confluence of the Sacramento and San Joaquin rivers between Martinez and Suisun City, California and several other smaller, local watersheds. Adjacent to Suisun Bay, the marsh is immediately west of the legally defined Sacramento-San Joaquin Delta as well as part of the San Francisco Bay estuary.
The California State Water Project, commonly known as the SWP, is a state water management project in the U.S. state of California under the supervision of the California Department of Water Resources. The SWP is one of the largest public water and power utilities in the world, providing drinking water for more than 27 million people and generating an average of 6,500 GWh of hydroelectricity annually. However, as it is the largest single consumer of power in the state itself, it has a net usage of 5,100 GWh.
Franks Tract State Recreation Area (SRA) is a state park unit of California, United States, featuring a flooded area in the Sacramento–San Joaquin River Delta. It is accessible only by water. Franks Tract, and a smaller adjoining submerged property called "Little Franks Tract", are situated between the False River and Bethel Island. The recreation area is used primarily for fishing and waterfowl hunting, because of its exposure to frequent strong winds and fluctuating water levels. In times of high water, the entire site can be submerged except for portions of the old levees. The 3,523-acre (1,426 ha) park was established in 1959. It is managed from nearby Brannan Island State Recreation Area, 6 miles (9.7 km) to the northwest.
The Peripheral Canal was a series of proposals starting in the 1940s to divert water from California's Sacramento River, around the periphery of the San Joaquin-Sacramento River Delta, to uses farther south. The canal would have attempted to resolve a problem with the quality of water pumped south. Pumps create such a powerful suction that the boundary between freshwater to saltwater has shifted inland, negatively affecting the environment. The pumps have increased by 5 to 7 million acre-feet the amount of water exported each year to the Central Valley and Southern California. However, the peripheral canal as proposed would have reduced the overall freshwater flow into the Delta and move the freshwater-saltwater interface further inland, causing damage to Delta agriculture and ecosystems.
The San Francisco Estuary together with the Sacramento–San Joaquin River Delta represents a highly altered ecosystem. The region has been heavily re-engineered to accommodate the needs of water delivery, shipping, agriculture, and most recently, suburban development. These needs have wrought direct changes in the movement of water and the nature of the landscape, and indirect changes from the introduction of non-native species. New species have altered the architecture of the food web as surely as levees have altered the landscape of islands and channels that form the complex system known as the Delta.
The CALFED Bay-Delta Program, also known as CALFED, is a department within the government of California, administered under the California Resources Agency. The department acts as consortium, coordinating the activities and interests of the state government of California and the U.S. federal government to focus on interrelated water problems in the state’s Sacramento-San Joaquin River Delta. The coordination program was created in 1994 by Governor Pete Wilson and federal Interior Secretary Bruce Babbitt following a decade of chaotic disputes between the state of California, the federal government, environmental groups, agricultural interests, and municipal water services.
California's interconnected water system serves almost 40 million people and irrigates over 5,680,000 acres (2,300,000 ha) of farmland. As the world's largest, most productive, and potentially most controversial water system, it manages over 40 million acre-feet (49 km3) of water per year. Use of available water averages 50% environmental, 40% agricultural and 10% urban, though this varies considerably by region and between wet and dry years. In wet years, "environmental" water averages 61%, while in dry years it averages 41%, and can be even lower in critically dry years.
The Mokelumne Aqueduct is a 95-mile (153 km) water conveyance system in central California, United States. The aqueduct is supplied by the Mokelumne River and provides water to 35 municipalities in the East Bay in the San Francisco Bay Area. The aqueduct and the associated dams, pipelines, treatment plants and hydroelectric system are owned and operated by the East Bay Municipal Utility District (EBMUD) and provide over 90 percent of the water used by the agency.
The San Francisco Estuary Partnership (Partnership) is one of the 28 National Estuary Programs created in the 1987 Amendments to the Clean Water Act. The Partnership is a non-regulatory federal-state-local collaboration working to restore water quality and manage the natural resources of the San Francisco Bay-Sacramento–San Joaquin River Delta estuary. The Partnership works with over 100 municipalities, non-profits, governmental agencies, and businesses and helps develop, find funding for, and implement over 40 projects and programs aimed at improving the health of the estuary. The partnership either directly implements these projects, or administers and manages grants, holds educational workshops and highlights project results. The Partnership is also the official representative for the San Francisco Bay region to the Most Beautiful Bays in the World.
Delta Conveyance Project, formerly known as California Water Fix and Eco Restore or the Bay Delta Conservation Plan, is a $15 billion plan proposed by Governor Jerry Brown and the California Department of Water Resources to build a 36 foot diameter tunnel to carry fresh water from the Sacramento River southward under the Sacramento-San Joaquin Delta to Bethany Reservoir for use by the State Water Project and the Central Valley Project.
The Old River is a tidal distributary of the San Joaquin River that flows for about 40 miles (64 km) through the Sacramento–San Joaquin River Delta in Northern California. The Old River was once the main channel of the San Joaquin until navigation and flood control projects in the late 19th and 20th century fixed the San Joaquin to its present course past Stockton. It diverges from the San Joaquin near Tracy, about 38 miles (61 km) upstream from Antioch, and first runs west towards Mountain House, then north to rejoin the San Joaquin 13 miles (21 km) above Antioch. The river is lined with levees that prevent flooding of the adjacent Delta islands, many of which lie below sea level. The Middle River runs east of and roughly parallel to Old River. False River diverges from Old River about a mile (1.6 km) above the Old River's mouth and runs westward to join the San Joaquin at a point closer to Antioch. Part of the Old River forms the boundary between San Joaquin County on the east and Contra Costa County to the west.
Stockton Deepwater Shipping Channel also called the Baldwin-Stockton Deepwater Shipping Channel or Stockton Deep Water Channel is a manmade deepwater water channel that runs from Suisun Bay and the Sacramento River - Sacramento Deep Water Ship Channel to the Port of Stockton and the Stockton Channel in California. The Stockton Ship Channel is 41 mi (66 km) long and about 37 ft (11 m) deep, allowing up to Panama Canal size ocean ships access to the Port of Stockton at the City of Stockton. The Stockton Deepwater Shipping Channel is part of the vast Sacramento–San Joaquin River Delta that has a connection to the Pacific Ocean. Stockton Deepwater Shipping Channel is also called the lower San Joaquin River.
Bradford Island is a 2,172-acre (879 ha) island of the Sacramento–San Joaquin River Delta, in Contra Costa County, California, United States. Bradford Island is inaccessible by roads, and is served by a ferry across the False River from nearby Jersey Island. Approximately 48 people lived on the island as of 2020; other uses of land include wheat farming, cattle grazing, and natural gas extraction.
Little Mandeville Island is a small, mostly submerged island in the San Joaquin River delta, in California. It is part of San Joaquin County, and its coordinates are 38.0104776°N 121.5649522°W. In 1994, 376 acres (152 ha) of former farmland was inundated with water after a levee broke.
Headreach Island is a small island in the Sacramento–San Joaquin River Delta, in northern California. A naturally-formed island existing in a complex with Tule Island to the southeast and Fern Island to the northwest, it was used for farming as late as the 1920s. While several proposals for real estate development on the island were made in the late 20th century, it now consists mostly of marsh and submerged land. Black rails live on the island.
