Skip to main content
USGS - science for a changing world

The Central Valley: Tulare Basin


The total population of the Tulare Basin in 2000 was approximately 4 million (Great Valley Center, 2005).

Major Cities

Fresno, Bakersfield, Visalia

Geographic Features

Tulare Lake Basin, Kettleman Hills, Kings River, Kaweah River, Kern River, Tule River, Tulare Lake, Kern Lake, Buena Vista Lake


The Tulare Basin has mild winters and hot dry summers. Despite transient tule marsh areas, the area is dry and the valley summer heat is intense.

Land Use

About 4% of the basin area is urban. The present-day Tulare Basin has been developed extensively for agriculture and petroleum extraction. Agricultural fields, vineyards, and orange groves are interspersed with oil fields (Parsons, 1987). Grains, cotton, and corn are the main agricultural crops in the Tulare Basin.

Water Use

Until recently, Fresno and Visalia were entirely dependent on groundwater for their supply, now these cities are slowly adding surface water to their supplies. Water used for agriculture in the Tulare Basin constituted 69% of the total water use in 1998 and 86% of the total in 2001 (Great Valley Center, 2005).

Surface water is preferred over groundwater because of relative costs. Uncertainty and limitations of surface-water deliveries from the Delta are of growing concern. Groundwater often is used to replace much of the shortfall in surface-water supplies. Because groundwater is a finite resource, alternate sources of water either are being considered or starting to be used.

The Central Valley

Delta & Eastside Streams

Sacramento Valley

San Joaquin Basin

Tulare Basin

Valley Facts

  • More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year
  • Approximately 75% of the irrigated land in California and 17% of the Nation's irrigated land is in the Central Valley
  • Using fewer than 1% of U.S. farmland, the Central Valley supplies 8% of U.S. agricultural output (by value) and produces 1/4 of the Nation's food, including 40% of the Nation's fruits, nuts, and other table foods.
  • The predominate crop types are cereal grains, hay, cotton, tomatoes, vegetables, citrus, tree fruits, nuts, table grapes, and wine grapes.
  • About 20% of the Nation's groundwater demand is supplied from pumping Central Valley aquifers, making it the second-most-pumped aquifer system in the U.S.
  • The Central Valley is one of the more notable structural depressions in the world.