Over the years, growers—particularly those who farm in the arid West—have
gotten a bad rap as water-wasters. Nowhere are the voices louder than in
California, which has faced droughts over the past three decades as well as
escalating competition among water users.
Many environmental groups criticize the state’s agriculture for using what
they perceive as wasteful irrigation practices. Many of these same groups
contend that if the state’s farmers would just conserve a tad more, it would
free up a lot more water for environmental or municipal uses.
A new report counters most of those critics by finding that by and large,
California agriculture is efficient in its use of irrigation. It also finds that
even if growers adopt the latest technology, it would free up little additional
water.
The report was prepared by California State University, Fresno’s Center for
Irrigation Technology. It was reviewed by a list of California Department of
Water Resources and University of California water experts and updates a similar document written in 1982.
The authors of the report found that growers could improve water use
efficiency by only 1.3 percent, which would free up 330,000 acre-feet. That
amounts to less than 0.5 percent of the state’s total water use of 62.66 million
acre-feet.
Critics point out that agriculture consumes 80 percent of the state’s
developed water. But when you look at how much water is dedicated to different
uses, such as wildlife, municipalities and industries, that figure drops to 40
percent for agriculture.
The public also may not realize that agriculture has given up 5 percent of
its surface water supply to environmental uses since the 1982 document was
written.
Sure, agriculture can always do a better job irrigating. Growers can avoid
irrigating during the heat of the day when evapotranspiration rates are the
highest, and they can regularly inspect irrigation systems to ensure nozzles
aren’t plugged or worn.
But with every change in irrigation practices comes a consequence—either
desirable or undesirable.
If growers, for example, installed tailwater return systems to catch runoff
that would otherwise return to nearby waterways, users downstream would be
affected by the reduced flows. So would wildlife.
Other critics have suggested that farmers take marginal ground out of
production, thus freeing up water for other uses.
But the reports’ authors say that shouldn’t be viewed as conservation but
instead a transfer of water out of agriculture. In addition, what happens to the
jobs that were tied to those irrigated fields?
In 2010, California’s farmers and ranchers received nearly $41 billion for
their production. Using an economic multiplier of 2.1, that means ag contributed nearly $86 billion to the state’s economy. Directly and indirectly, the industry was responsible for more than 1.3 million jobs.
Despite this latest evidence supporting agricultural irrigation efficiency,
you can bet that at least some criticism will continue to flow.