Dealing with the Drought: A Q&A with Dietitians

Posted May 9th, 2016

For those of us who live in California, the state’s historic drought is never far from our minds, particularly if working in the area of food. A recent presentation at the California Academy of Nutrition and Dietetics (CAND) annual meeting, Behind the Headlines: A Closer Look at the Impact of Drought on California Crops, gave registered dietitian nutritionists – who are on the front lines answering patient, consumer and media questions about food and nutrition – an overview of this critical issue, and what the California almond community is doing to manage water responsibly and efficiently.

Interest in the topic was high, and the speakers – Alissa Kendall of the UC Davis Department of Civil and Environmental Engineering, and Danielle Veenstra and Jenny Heap, both Almond Board of California staff – were peppered with questions following their presentation. Here’s a sampling of the questions most top-of-mind from the audience of dietitians:

I read an article that almonds use 10% of California’s water resources. Is that true?

That 10 percent value is based on an incorrect (and since corrected) article in Slate. Almonds account for 14 percent of the California’s irrigated farmland, but they use only 9.5 percent of the state’s agricultural – not total – water.[i] That’s an important distinction.

There’s a misperception that the shift towards higher value, perennial crops like nuts and wine grapes has led to an increase in the amount of California water devoted to agriculture. However, according to the Department of Water Resources, the total amount of agricultural water has held steady since 2000, and has actually declined over a longer period.[ii] The fact is, almond trees need about the same amount of water as other California fruit and nut trees.

When you consider the benefits of almonds – the nutrition that they provide, coproduct utilization of all three parts of the almond (shell, hull and kernel) and economic value to California – growing almond trees is an efficient and effective use of agricultural water. For more information, check out our The Bigger Picture: California, Almonds + Water infographic.

I’ve seen a lot of information about farmers pumping groundwater and depleting aquifers. Can you explain this?

Groundwater is pumped for agricultural, urban and environmental uses. An appropriate analogy for groundwater is that of a savings account.  During dry years, the water is withdrawn (pumped), and can be restored with deposits (recharged) during wet years to maintain healthy and sustainable groundwater basins. During normal water years, groundwater is naturally recharged by winter rains and snowpack.

Given the extended drought California has experienced, the volume of pumped groundwater has been more than can be reasonably expected to be recharged, without coordinated efforts to increase recharge.

Some almond growers have already been experimenting with utilizing excess winter flood flow water for groundwater recharge for several years.  We’ve recently launched a partnership with an environmental non-profit Sustainable Conservation, UC Davis researchers and others to accelerate the recharge potential of the Central Valley. More than 675,000 acres of California almond orchards have been identified as moderately good or better in their suitability for groundwater recharge, and through this partnership, we’re working on methods to increase recharge.

For example, this past winter, UC Davis researchers flooded experimental orchards with two feet of El Niño storm water to measure impacts on tree health, yields and water quality and quantity. Researchers have been measuring how much water actually permeates down to the tree roots, and also monitoring water quality to ensure no detrimental effects.

What watering methods do almond growers use?

Technology plays a significant role in helping almond growers with water efficiency. Among almond growers, 83 percent practice demand-based irrigation, which means they track soil, tree and weather conditions to make irrigation decisions, instead of using a fixed watering schedule.[iii] And, due to its water efficiency, micro-irrigation is used by 70 percent of almond growers, which makes them lead adapters of this technology.3 Over the past 20 years, almond growers have improved their water use efficiency by 33 percent, producing more “crop per drop.”[iv]

Consider the irrigation methods used by California farmers overall compared to those used by almond growers:

The Almond Board is continually looking at ways that almond growers can improve water use efficiency. As part the Almond Board’s new sustainability-related initiatives, we’re developing accessible resources and decision support tools around irrigation education, specific to California almonds. And we work with growers in the field and irrigation specialists to share best practices.

Watch this space for the newest information on the California almond community’s sustainable farming practices, along with news on many other important topics. 

[i] USDA/NASS. 2015 California Almond Acreage Report. Apr. 2016.

[ii] California Department of Water Resources. California Water Plan Update 2013: Volume 4. Feb. 2015.

[iii] California Almond Sustainability Program. Jan. 2014. USGS. National Water Information System: Web Interface. Nov. 2014

[iv] University of California. UC Drought Management. Feb. 2010. Food and Agriculture Organization of the UN. FAO Irrigation and Drainage Paper 66 – Crop yield in response to water. 2012. Almond Board of California. Almond Almanac 1990-94, 2000-14.