Delta History

California's Delta shares the distinction with the Nile River of Egypt as being one of the most easily recognized triangular (delta) shaped landmasses in the world, if viewed from the vantage point of a satellite orbiting the earth.

With two-thirds of all Californians getting their water from its sources, it could be argued that the Delta is also the most important region in the state. On land, however, the Delta becomes less obvious and more difficult to explore with rivers and highways dividing the region into a multitude of districts and counties.

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The Delta is formed by the confluence of the state’s two largest rivers: the Sacramento flowing south from its headwaters near Mt. Shasta and the San Joaquin flowing north from its origins high in the southern Sierra Nevada. Joining the Sacramento and the San Joaquin are the Mokelumne and the Cosumnes Rivers, that comprise the Delta’s watershed, draining nearly 50 percent of the state’s runoff. Through a maze of 57 man-made levee islands and tracks, these waters of the Delta flow westward. Pumping stations move a portion of this water throughout the state: the State Water Project, the federal Central Valley Project, Contra Costa Canal, North Bay Aqueduct, City of Vallejo diversion and the Western Delta Industry diversion. The remainder of Delta water flows to farms and communities within the Delta, and then out to sea through a series of bays.

The Delta is unlike any other large restoration program in the nation whose primary focus is its ecosystem. The Delta is managed by CALFED with four equal priorities: ecosystem restoration, water supply reliability, water quality and levee system integrity. Thus, the Sacramento-San Joaquin Delta is under much greater pressure to perform against these four objectives than other estuaries, notably the Everglades of Florida and the Chesapeake Bay of Maryland.

Life in the Delta: The Delta is many things to many people. It is rural living at its best in small towns and villages where motorists occasionally have to stop for tractors and drawbridges. It is a paradise for boaters and fishermen; an adventure for tourists, antique collectors and wine connoisseurs. The Delta offers resort living in small towns, levee-hugging villages and islands surrounded by water. But its bucolic, sleepy exterior masks the fact that the Delta is vitally important to the economy of California and that the Delta as we know it is not sustainable in the future.

The West’s Largest Estuary: The Delta plays a major role in the state’s prosperity by providing at least a portion of the drinking water for 24 million Californians, fueling a $31 billion agricultural industry and serving as an important habitat to more than 750 animal and plant species and many non-native species, including waterfowl, birds of prey, sport fish and species listed as threatened or endangered: Delta smelt, Chinook salmon and steelhead. The 1,000 square-mile estuary supports 80 percent of California’s commercial salmon fisheries and its 1,100 miles of levees protect farms, cities, schools and people.

More than half-a-million people call the Delta home, living in 14 towns and villages in five counties. Five highways pass through the Delta, as do three railroads, two deep-water shipping channels, hundreds of natural gas lines and five high-voltage transmission lines. Water flowing through the Delta diverts directly through six canals and/or pipelines and to more than 1,800 agricultural users, the latter of which grows half the nation’s fruits and vegetables and one-quarter of its dairy products.

Early Time Line of Delta Events *Source: Department of Water Resources

  • 1772
    • First recorded sighting of Delta by Fray Juan Crespi and Captain Pedro Farges.
  • 1776
    • San Carlos--first ship to enter San Francisco Bay.
  • 1849
    • Settlers begin arriving in the Delta to farm its rich soils while Forty-Niners pass through on their way to strike gold in the Sierra foothills.
  • 1850
    • Congress passes the Federal Swamp and Overflow Act, which provided for the title of wetlands to be transferred from the Federal Government to the states.
  • 1861
    • California Legislature authorizes the Reclamation District Act, allowing drainage of Delta lands and construction of sturdier levees.
  • 1869
    • Sherman Island is the site of the first coordinated levee system in the Delta.
  • 1879
    • Prized by fisherman, the Striped Bass is brought by rail from the East Coast to the Delta. Two more shipments are required before the fish is established.
  • 1880
    • Most of the Delta reclaimed using dredges developed to build levees quickly and inexpensively. By 1930, all but minor areas of swampland had been leveed and were being farmed.
  • 1884
    • Federal Circuit Court decision in Woodruff v. North Bloomfield, et al., requires termination of mining debris discharges into California rivers. Hydraulic mining had deposited tens of silt and sand in Delta channels and up- stream rivers.
  • 1900
    • California's population is estimated at 1.5 million.
  • 1902
    • Congress passes the Reclamation Act for develop- ment of irrigated lands in the western United States.
  • 1911
    • The Reclamation Board is created by the California Legislature to implement a comprehensive flood control plan for the Sacramento and San Joaquin rivers.
  • 1914
    • California Legislature passes bill to revise water right law regarding appropriation of surface water.
  • 1930
    • State completes comprehensive investigation of Delta salinity and its control, and also the State Water Plan (now the Central Valley Project) to transfer northern California water throughout the Central Valley.
  • 1933
    • Corps of Engineers dredges Stockton Deep Water Ship Channel to Port of Stockton.
    • Congress authorizes the Central Valley Project (CVP).
  • 1940
    • Export of Delta water begins with U.S. Bureau of Reclamation (USBR) completion of the Contra Costa Canal, the first unit of the CVP.
  • 1944
    • Shasta Dam and Reservoir completed as a key feature of the CVP; adds water to Delta channels during low-flow periods, thereby limiting salinity intrusion. 1951 Delta export increases with completion of the Delta-Mendota Canal, another unit of the CVP.
    • USBR constructs the Delta Cross Channel to aid in transferring water from the Sacramento River across the Delta to the Tracy Pumping Plant, which serves the Delta Mendota Canal.
  • 1959
    • State Legislature passes the Delta Protection Act and the Burns-Porter Act to assist in financing the State Water Project, including Delta facilities. The SWP, which would increase Delta exports, was approved by California voters in 1960.
  • 1960
    • California voters approve the Burns-Porter Act (also called the State Water Project Development Bond Act) authorizing the sale of $1.75 billion of general obligation bonds to help finance the SWP. California's population is 15.7 million.
  • 1963
    • Corps of Engineers dredges the Sacramento Deep Water Channel to the port of Sacramento.
  • 1965
    • Interagency Delta Committee, formed in 1961, completed its report recommending various Delta facilities, including the Peripheral Canal, to offset adverse effects of increasing Delta exports.
  • 1967
    • Oroville Dam and Reservoir is completed as a key feature of the SWP and the Feather River Fish Hatchery is opened to replace spawning areas lost as a result of the dam.
    • The first stage of the Harvey O. Banks Delta Pumping Plant is completed along with the John E. Skinner Fish Facility.
  • 1971
    • State Water Resources Control Board (SWRCB) adopts its Delta Water Rights Decision 1379 establishing Delta water quality standards to be met by the Central Valley Project (CVP) and SWP.
  • 1973
    • California Aqueduct completed to Southern California.
    • Legislature passes Senate Bill 541 (also known as the Way Bill) to provide State financial assistance for maintenance and improvement of certain Delta levees.
    • Delta Environmental Advisory Committee (DEAC) concludes that a federal-State Peripheral Canal, properly designed and operated, is necessary to protect the Delta. 1978 SWRCB issues Water Right Decision 1485 updating Delta water quality standards and establishing water quality standards for Suisun Marsh.
  • 1980
    • State Legislature passes Senate Bill 200 specifying the Peripheral Canal as the Delta water transfer facility, requiring staged construction and fish screen testing but without requiring federal participation.
  • 1982
    • California voters defeat Proposition 9, which includes the Peripheral Canal, the SB 200 package of statewide facilities, and Delta protection, by a 3-2 margin. 1986 Congress passes DWR and USBR historic accord, the CVP-SWP Coordinated Operation Agreement.
    • California Supreme Court affirms State court of Appeal ruling (Racanelli Decision) strengthening SWRCB powers to protect the Bay/Delta system. The Racanelli Decision covered eight cases challenging SWRCB's Decision 1485, issued in 1978, and its Water Quality Control Plan for the Delta and Suisun Marsh. The decision recognizes SWRCB's broad authority and discretion over water rights and water quality issues, including jurisdiction over the federal CVP.
    • DWR and the Department of Fish and Game sign the Delta Pumping Plant fishery mitigation agreement for direct fish loss.
  • 1987
    • DWR installs Middle River Weir as part of an agreement with the South Delta Water Agency to improve water conditions for local agricultural diverters. It is the first component of a temporary program designed to provide data for a more permanent solution.
  • 1988
    • DWR completes pumping plant for North Bay Aqueduct and the Suisun Marsh salinity control gates.
    • Legislature passes Senate Bill 34, which provides $120 million over a l0-year period for DWR to rebuild Delta levees, enlarge channels, and help reclamation districts make levee improvements.
    • An engineering study by the California Urban Water Agencies examines options for improving drinking water quality for users of Delta water.
  • 1990
    • California's population is now 29.8 million. (1990, U.S. Census)
  • 1991
    • Construction completed on four additional pumping units at the Banks Pumping Plant.
  • 1992
    • The Legislature passes the Delta Protection Act of 1992 establishing the Delta Protection Commission. The Commission is to develop a comprehensive, long-term resources management plan for the Delta by July 1, 1994.
    • Congress passes the Central Valley Project Improve ment Act (PL 102-575) which allows water transfers from CVP contractors to other water users, reforms water pricing, and commits up to 800,000 acre-feet annually to fish and wildlife purposes.
    • Governor establishes Bay-Delta Oversight Committee for long-term Delta planning.
  • 1993
    • The Delta Smelt is listed as a Threatened Species and actions are defined (such as pulse flows on the Sacramento River and limitations on certain flows within the Delta) to improve conditions for the smelt and the Winter-run Salmon tan Endangered Species).

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