PPIC Water Policy Center

Roughly half of California’s water systems experiencing consistent water quality problems are in the San Joaquin Valley.

Damaging floods are common in California. Over the past 60 years, every county has been declared a state or federal flood disaster area multiple times.

Roughly 75% of California’s precipitation occurs north of Sacramento, but 75% of California’s water use occurs south of Sacramento.

California’s mountainous headwaters occupy roughly one third of the state but provide two thirds of its surface water.

Roughly a third of the state’s annual water supply is stored as snowpack that melts during spring and early summer when water demands are high.

The Colorado River provides roughly a third of all supplies for Southern California cities and suburbs, and supports a large farming industry.

88% of the energy consumed by California’s water sector goes to residential and business uses.

California’s productive farm sector requires large volumes of water for irrigation, typically four times the annual use of cities.

Roughly half of the water used in California cities is for landscape irrigation.

A quarter of California’s native freshwater fishes—key indicators of aquatic ecosystem health—are listed as threatened or endangered, and many others are vulnerable.

In a typical year, groundwater provides about a third of total farm and urban water use. Since 2014, this share has exceeded 50 percent.

Two-thirds of California’s population and more than 3 million acres of irrigated farm land depend in part upon water exports from the Sacramento–San Joaquin Delta.