Water Supply Reliability

California’s Agricultural and Urban Water Supply Reliability and the Sacramento-San Joaquin Delta

Jay Lund

Full article

Key points:

  • Much of the water supplied in California for agriculture and cities is taken directly from the Sacramento-San Joaquin Delta (Delta) or indirectly from surface and groundwater diversions upstream.
  • The reliability of water supplied from the Delta is threatened by drought, flood, climate change, earthquakes, growing water demands, and deteriorating conditions for endangered species and native ecosystems.
  • Tighter accounting and modeling of water supplies in the Delta and throughout its watershed are needed as reliability diminishes.
  • Research in recent years has improved understanding of how management of the Delta ties together the quantity and quality of water available statewide, from the Sierra mountains and coastal streams, through the Central Valley, to the San Francisco Bay Area, and over the Tehachapi Mountains to southern California.