By Heather Cooley, Director, Pacific Institute Water Program, and Claire O’Connor, Senior Attorney and Agricultural Water Policy Analyst, NRDC Water Program
June 10, 2014
This article is cross-posted at the NRDC Switchboard.
For many California farmers, this growing season has been the “worst of times”. While all of the state is in the midst of a severe drought, conditions are most acute in the state’s most productive agricultural region.
The full impact of the drought on the state’s agricultural regions is not yet quantified, but preliminary results from a University of California- Davis study suggest that Central Valley farms will receive 6.5 million acre-feet less surface water than under normal conditions.
This is bad news not just for California farmers, but for all of us. California is the most productive agricultural state in the nation, growing about half of the fruits and vegetables produced in the United States. Limited water supplies mean smaller crop harvests, higher costs for farmers, and potentially even higher prices for some commodities.
It’s also bad news for California’s groundwater resources. In an average year, groundwater provides an estimated 40% of the state’s water supply and up to 60% during a drought, making it not only an important primary water supply but also a critical “backup” dry year supply for many water users. Many of California’s groundwater basins, especially in the San Joaquin Valley, are already painfully overextended, causing the ground to sink nearly one foot per year in some parts of the state and threatening the structural integrity of the state’s water delivery system. Furthermore, declining groundwater levels mean that wells will go dry, water quality will decline, and some farmers and other water users will lose a key water supply, making dry years even more painful.
But there’s a glimmer of hope, and an opportunity to transition to far better times for California’s tough and dedicated farmers. “Untapped Savings,” an analysis released today by the Pacific Institute and NRDC, reveals that efficiency could reduce agricultural water use by 5.6 to 6.6 million acre-feet annually. That’s enough water to make up the shortage in surface water predicted by UC Davis, even during this exceptionally dry year, speaking to the power of efficiency as a drought-resiliency technique. So what does this drought-resilient farm of the future look like?
- Drip Irrigation- Farmers who use drip irrigation apply low volumes of water directly to crops’ root zones. This technology can use 21% less water than traditional gravity irrigation, where water is applied by flooding the area between crop rows.
- Irrigation Scheduling- Crops need different amounts of water during different stages of growth. A farmer who uses irrigation scheduling closely tracks the amount of water crops are using, monitors weather and soil conditions, and times watering to match crop needs. Farmers in the Pajaro Valley who use this technique were able to reduce their water use by 30% while maintaining yield.
- Regulated Deficit Irrigation- With this technique, a farmer strategically reduces the amount of water applied during certain drought-tolerant stages. The reduced water helps to improve crop quality, and is especially popular among tree nut, wine grape and other fruit growers.
There’s not much we can do to make it rain, but there are steps we can take to prevent the worst impacts of dry periods for California farmers. Some California farmers have already adopted these and other efficiency practices. Further adoption of modern irrigation technologies would help make California agriculture more drought-resilient and ensure that groundwater resources are available during dry years. By expanding adoption of drip irrigation, irrigation scheduling, regulated deficit irrigation, and other efficiency practices on our farms, and in the irrigation districts that serve them, we have an opportunity to transform this “worst of times” into a new era of prosperity and resilience for California agriculture.
For more information about the 21st Century water supply solutions for our farms, cities and homes, which together can offer enough water savings and demand reductions to irrigate all of the fruits, vegetables, and nuts in California each year, check out our Untapped Savings website.