California’s Agricultural Water Usage: What You Should Know

California’s massive agricultural industry rivals many nations’ food production. But the water required to sustain such an operation is just as hefty. Let’s break it down.

Updated: January 5, 2024
Jeremiah Zac


The State of California can’t seem to escape public attention, whether for economic, political, or social reasons. 

But if there’s one thing that’s undeniable, it’s that California is an absolute agricultural phenomenon responsible for a large percentage of the country’s food production.

However, all of that vast, fertile farmland comes with a hefty price, paid for in water. And much of it needs to be transported from sources much further from where it’s used, which is no wonder why the state is seemingly in perpetual drought.

Let’s have a deeper look into why California is such an agricultural powerhouse and how it maintains enough water for its production.

Impressive facts about California agriculture

California’s unique climate and soil constitution allow for growing conditions that make the state one of the most productive agricultural regions in the world. Here are some facts about California's agriculture.

1. California is one of only five Mediterranean climate regions in the world

A Mediterranean climate zone is roughly defined as a region located between 31 and 40 degrees latitude north and south of the equator and provides the best conditions for growing crops. Aside from California, the four other regions with Mediterranean climate zones are Chile, South Africa, Australia, and, of course, the Mediterranean.

2. California is the largest investible space for high-yielding permanent crops in the world

Permanent crops, as opposed to row crops, are crops that continue to produce year after year rather than having to be replanted after each harvest. Two-thirds of the country’s 5 million acres of permanent crops are in California, making it the largest permanent crop region in the world.

3. California is the fifth-largest food supplier in the world

California’s agricultural production is incredible, supplying more than 400 different crops. It is the world’s leading producer of pistachios and almonds, responsible for 50% and 82% of the world’s supply, respectively.

4. California is the nation’s top agricultural producer and exporter

The state of California alone accounts for a third of the country’s vegetable production and two-thirds of fruit and nut production. It is the country’s leading producer of over 74 commodities, including avocados, grapes, lemons, and strawberries, and it is the country’s sole producer of 13 specialty crops.

How much water does California use for Agriculture?

California Water Use / Department of Water Resources

A simple Google search about the amount of water used for agriculture in California will bring up various percentages headlined on varying news articles, making it difficult to determine an exact number. 

The reason for some of these variances is likely due to how the data is being interpreted and the context in which it is being presented. So, to make the most sense of agriculture water data and to get the most accurate reading, let’s first break down how water in California is used.

Water use in California is roughly divided into three sectors: environmental, agricultural, and urban.

Environmental water use mostly accounts for natural infrastructure, which includes the replenishing of rivers, instream ecosystem use, water quality maintenance for communities and farms, and wetlands within wildlife preserves.

Agricultural water use accounts for irrigating the 9 million acres of cropland, and urban use accounts for the water directed to cities.

Environmental water use takes up the bulk of the total water used in the state at 50%. Agriculture uses 40%, and urban areas use 10%.

Some headlines publicize that agriculture takes up 75-80% of the water use in California. While this isn’t entirely inaccurate, it is a bit misleading as these numbers don’t take into account the environmental use of water, which is the largest.

Regardless, 40% of the total water used for agriculture is enormous, and most of it is diverted through a complex irrigation system.

Where does California get its water?

Most of California’s precipitation comes from the Northern third of the state, while the majority of the water demands are in the Southern two-thirds. Because of this imbalance, a series of elaborate irrigation systems are used to divert water to where it is needed.

State Water Project

The State Water Project (SWP) is one of the world’s most elaborate irrigation systems, consisting of a series of dams, reservoirs, pumping and power plants, and aqueducts, and supplies water to more than 27 million people and 750,000 acres of farmland. It sources water from the Sierra Nevada snowmelt and uses a 444-mile-long aqueduct to transport water from the San Joaquin Valley to Southern California, supplying major cities such as Los Angeles, Riverside, San Bernardino, and San Diego.

The Central Valley Project

The California Central Valley, a vast fertile farming region consisting of the Sacramento and San Joaquin Valleys, receives much of its water via the Central Valley Project, a massive series of 20 reservoirs and 500 miles of canals and aqueducts. Diverting water from Lake Shasta, the CVP delivers 7 million acre-feet of water to 3 million acres of Central Valley farmland.

Colorado River

The Colorado Aqueduct, operated by the Metropolitan Water District of Southern California (MWD), delivers water from the Colorado River to Southern California, where it’s used to irrigate farmland in Imperial and Coachella Valleys.

Moving forward

Because of the limited water supply in California, tensions between farmers in rural areas and city dwellers in urban areas are palpable, giving rise to political and economic disputes about who has first rights to the water source.

Drought has been an ongoing issue in the arid Western states, particularly in the desert regions of Southern California.

In order to help solve some of its water problems, California proposes some strategies to help conserve some of its water reserves and curtail widespread overuse.

Wastewater recycling for non-potable uses has been performed for decades in California, but a recent board decision will allow plans for direct potable reuse—a process that converts wastewater into purified drinking water.

Efforts to improve the efficiency of desalination—the process of converting seawater into drinking water—are continuing steadily with plants in Carlsbad and San Luis Obispo County.

For homes in wetter regions of the state, rainwater harvesting can prove to be an effective means of conserving water use on the property and significantly lowering one's water bill.

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I'm Jeremiah, the owner of World Water Reserve. I'm a writer and researcher with a particular interest in sustainability and rural living, water scarcity, and innovative water purification methods. I utilize my multimedia and communication experience in the NGO and humanitarian fields to bring light to important topics. My passion is to educate others on the reality of the global water crisis and on ways to sustain themselves and their families in the midst of it.
Jeremiah Zac