What Is The Bay-Delta?

Travel any coastline, and you'll find an estuary -a place where salt water and fresh water meet. The Bay-Delta is the largest estuary on the West Coast, and home to nearly 750 species of plants and animals.

The bay is San Francisco Bay, with the city of San Francisco about 30 miles to the southwest of the Delta and a waterway that extends inland for dozens of miles through San Pablo Bay and Suisun Marsh.

It's a delta because this is where several rivers converge. The Sacramento River begins hundreds of miles to the north, passes through Lake Shasta and flows south, where it's joined by the Feather River as it courses south from Lake Oroville, the key reservoir of the State Water Project, and the American River flowing westward from Folsom Lake. The San Joaquin River begins in the Sierras and flows north to the Delta.

Water feeding the Bay-Delta comes from as far north as Lake Shasta and as far south as Visalia -from point to point, that's a distance close to 400 miles as the crow flies.

Although "Sacramento" is part of the official name, it refers to the river as opposed to the city of Sacramento, which actually is a short commute to the north. Stockton lies to the southeast, and would be among the first cities flooded if the levees break. Contra Costa is practically a next-door neighbor, and one of the first to take delivery of water from the system.

The rivers are only one of many different bodies of water. To the west (nearer to ocean) are the bays, like Suisun Bay. The rivers branch off into forks, and are scattered among canals and dozens of sloughs, along with the Sacramento and San Joaquin River Deep Water Shipping Channels-stretches of the Sacramento and San Joaquin rivers that have been dredged by the Army Corp of Engineers so that oceangoing vessels can get to the ports of Sacramento and Stockton.

The land sections of the Bay-Delta are alternately called islands or tracts. Most of these are devoted to farming, and are protected by levees. Suisun Marsh lies to the west.

In terms of the interaction between local farming, fisheries and water supplies, the key areas are the Central Delta (near Franks Tract) and the South Delta (nearer the pumping plants of the federal and state water projects). These areas have slightly different sets of conditions and issues.