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California's Agricultural System Needs to Adapt to Drought and a Changing Climate

When it comes to produce, as a Bay Area native I’ve always been spoiled. Californians can purchase fresh berries, kiwis, lemons, artichokes -- along with all the other fruits and vegetables California produces in breathtaking quantities -- almost year round. California is frequently considered “the fruit basket of America,” with an agricultural economy estimated at around $50 billion. However, when drought hit the state in 2011 and stayed for what seemed like an endless stretch of time, Californians (and the rest of the country) were forced to take a closer look at the state’s agricultural system. 

In 2015, at the height of the drought, 80% of the water used in California was for agricultural purposes, concentrated in the central and southern regions of the state. Browning trees, forest fires and urban water-use regulations forced us to ask: What is the cost of using so much of California’s water for agriculture? The fruits and nuts grown in central and southern California constitute over 60% of the nation's overall cultivation of these crops, helping California earn its status as the top agricultural producer in the United States. In considering the national importance of this agricultural system, how should California adapt its agricultural system in the face of climate change and increasingly limited supplies of potable water?

The water used for agriculture in California is primarily diverted from streams and rivers, as well as underground aquifers and the snowpack of the Sierras located in the northern part of the state. California has a complex system of man-made canals, reservoirs and aqueducts that utilizes the force of gravity and pumping mechanisms to channel water from the northern region of the state through the San Joaquin Delta and down into the Central Valley and southern California. The Delta is the key to this system; most of the water that flows through northern California naturally flows into the Delta without any human intervention. Until it was drained and diked in the early 1900s, the Delta it was actually a tidal wetland. However, farmers worked to convert the Delta into a series of channels surrounded by arable agricultural land. Later in the century, further engineering introduced pumps, aqueducts and constructed channels to more effectively divert water from the Delta to the southern portion of the state. This system was once lauded as an engineering feat. However, climate change and resultant drought have recently elucidated its flaws. 

For one, California’s water system relies on an expanse of surface-level channelized streams that flow through agricultural lands. Levees ensure that the water flowing through the delta doesn’t spill onto adjacent farmland. However, channelized rivers can’t adjust well to hold increased water volume so they’re prone to flood when excess water flow occurs. Climate change is making this a more frequent occurrence as the drought-flood cycles of the state are becoming increasingly severe and volatile. When flooding occurs, water can spill onto farmland. When the water washes back into the channel, it can bring with it the pesticides applied to crops. This is a big problem because, aside from fueling the agricultural economy of the state, the San Joaquin Delta serves as the primary source of drinking water for California residents, supplying water to over 25 million people. 

Diverting water to downstate agriculture is also straining the aquatic ecosystems of California, especially that of the San Joaquin Delta. The San Joaquin Delta, although partially man-made, houses a number of endangered and keystone species (species that are vital to the ecosystem’s health). As more water is pumped down to the southern and central portions of California, water volume in this delta and the streams that feed into it has decreased. The effects of this reduced streamflow are severe. Less water in streams is linked with disruption of nutrient cycles, diminished fishery health and overall poor water quality.  The fisheries of the delta, notably those for salmon and smelt, are increasingly on the verge of utter collapse. 

Most of all, California’s over-engineered water system seems to rest on the assumption that freshwater diverted primarily from northern California will be able to support an unlimited agricultural economy. In the face of climate change, that is increasingly untrue. California’s seven-year drought, fueled by several factors including decreased precipitation and reduced snowpack in the Sierra Nevada mountains, has demonstrated that our water supply is limited. 

We of course cannot choose between water and food -- we need both. But we can change how, where, and which crops we produce -- and we must do so in order to adapt to the changing climate.

California is at a critical moment when it comes to water policy. In response to the declining ecosystem health of the San Joaquin Delta, in recent years California legislators have developed state legislation that would increase flow through the delta and divert less to downstate agriculture. In an act that environmentalists believe favors agriculture, Governor Gavin Newsom vetoed such a bill last month. Meanwhile, a plan to divert even more water to California’s agricultural economy has been in the works for a number of years. Called “California WaterFix,” the plan would construct two large tunnels underground, funneling water from the streams that feed directly into the Delta, down to the central and southern part of the state. Despite pushback that this plan would further aggravate ecosystem degradation, California WaterFix is still in the works, currently in the process of environmental review. 

If California were to divert less of its water for agriculture, how might its agricultural system adapt? One option is to grow less water-intensive crops. California produces some of the nation’s thirstiest crops, such as tree nuts. In 2018, California sold $ 5.47 billion worth of almonds alone. It has been estimated that almonds use about 10% of California’s water supply. Cultivating almonds isn't a bad thing; almonds are high in calories, nutritious, healthy and profitable. However, they are among the least water-efficient crops produced in California, along with cherries and walnuts. These are all particularly profitable crops, but in the context of dwindling water supplies, the cost/benefit analysis of such crops needs to be rethought.

In addition to growing less water-intensive crops, we can also grow less in general by wasting less food. It is estimated that Americans waste between 30-40% of our food. There are a lot of factors that contribute to food waste; grocery stores will throw away aesthetically unappealing foods, consumers will lose track of how fast their groceries go bad, restaurants serve portions larger than most people can consume, and so on. Underlying this propensity to waste is the fact that food is cheap here; agricultural subsidies manipulate the true environmental and material costs of cultivating food, making it artificially inexpensive. People are far more willing to forget about and throw away food that's cheap. If Americans threw away less food, we might need to produce less and less water would need to be used, a step in the direction of preserving some of the most important waterways in our nation. 

California produces a lot of delicious, nutritious and necessary food - a reality that a Bay Area native like me experiences every time I go to the grocery store. In the face of climate change and the potential for recurring, devastating drought, however, we need to reconsider how, where, and which crops are produced in order to conserve our water resources. There are countless ways to do so, enabling us to begin the necessary re-engineering of a faltering system.

Photo: Pacific Southwest USFW via flickr