Two-thirds of California’s rainfall is in the northern portion of the state, while two-thirds of all Californians live in Southern California. In order to protect from drastic flooding and to ensure water to the entire population, the 20th Century saw two major infrastructure projects designed to transport much of that water to Central Valley farms and the urban dwellers of Silicon Valley, Los Angeles and the Southland:
(1) The Central Valley Project (CVP) – Federal Surface Water system devised & constructed in the 1930’s.
(2) The State Water Project (SWP) – Constructed in the 1950’s & 1960’s, culminating in the construction of the San Louis Reservoir – the final large water facility shared by the CVP & SWP.
Both projects share the same infrastructure of dams, pumps and canals, and are both dependent on drawing water from the Delta. As such, water users only know what type of water they receive based on who their check is made out to – either the federal or state government.
When these two water projects became fully operational in the 1960s, California’s population was at only about 20 million. Considered the envy of the world, California’s water system played a large part in catapulting the state to become the 5th largest global economy in less than 100 years. During this period, farmers and residents, who experienced ample supplies, shared California’s water supply.
This all changed with the advent of the Endangered Species Act (ESA), which introduced a third stakeholder into the mix – fish and the environment. The major area of concern in the ESA centered on the Delta – the heart of both the CVP and SWP water projects.
This development – coupled with the fact California has added 18 million more people to the state (38 million to date) – not only created skyrocketing demand, but there was no additional supply of water, in large part because development of major infrastructure ceased entirely in the 1960s.
From the 1970s to present, the environment has claimed an even larger portion of California’s precious water supply. An estimated 82% of all California water flows through the Delta, where it remains or flows to the ocean. Just 18% is allocated to Central Valley farmers and residents of the Bay Area and Southern California.
Today, California’s total developed water supply is divided, with 48% going to environmental projects and programs, 41% to agriculture, and 11% to cities statewide.