Add Precision To Irrigation Water Use

Kurt LawtonConservation, Education, Irrigation, Research, sustainability

The battle for water between agriculture and urban use only continues to gain momentum, yet both sides must focus on further efficiency.

In California, a new study by the Pacific Institute points to ways that agriculture can still flourish despite diminishing water supply and uncertain climate change. But, new steps to significantly increase water use efficiency must be taken.

The good news is that many farmers and irrigation districts have already been making water-use efficiency improvements. The better news is that there is still tremendous untapped potential – in millions of acre-feet. Policy and water management changes are imperative to capture this potential.

The new report, Sustaining California Agriculture in an Uncertain Future, quantifies the potential to maintain and even increase agricultural productivity while reducing agricultural water withdrawals and vulnerability to drought and climate change. The analysis estimates that potential water savings of between 4.5 – 6 million acre-feet each year can be achieved statewide by comprehensive changes in the irrigation technologies and management practices we use to grow California’s crops. In comparison, this savings is 19 times the amount of water returned to the environment through the recent Delta smelt ruling.

The Institute looked at three water management scenarios:

 Efficient Irrigation Technology – shifting a fraction of the crops irrigated by flooding fields to sprinkler and drip systems;
 Improved Irrigation Scheduling – using local climate and soil information to help farmers irrigate more precisely; and
 Regulated Deficit Irrigation – applying less water to certain crops during drought-tolerant growth stages to save water and improve crop quality.

“The three scenarios we evaluated for improving the efficiency of water use in California agriculture all show the potential for significant water savings,” said Dr. Peter Gleick, president of the Pacific Institute, “and these are technologies and management strategies that we could implement now, if we would recognize the urgency and have the will to make the tough decisions and policy changes.”

Many farmers have worked hard to improve water-use efficiency in recent years, but the Sustaining California Agriculture report shows that significant potential for water savings remains. For example, an astounding 60% of crops are still irrigated in California by flooding the field – a practice that leads to unproductive water loss. Conversion to sprinkler and drip irrigation allows farmers to apply water with greater precision and uniformity. Other management practices, such as irrigation scheduling and regulated deficit irrigation, have also been shown to reduce water use while improving crop quality and/or yield.

The report features several “early adopters” from the agricultural community, growers who have implemented water conservation and efficiency improvements to benefit both their future and their bottom-line. Craig McNamara, owner and operator of Sierra Orchards, has converted many fields to drip irrigation and installed tailwater recovery ponds to capture excess water runoff. “Conservation has to be a critical part of what we’re doing on the farm and as citizens of California,” stressed McNamara. A video clip and transcribed interview with Craig McNamara is available at the Pacific Institute’s website:

Key to success in making water efficiency improvements for farmers like McNamara has been financial support from federal, state, and local programs. The new report makes specific recommendations to expand this support, such as property and sales tax exemptions, rebates for efficient irrigation equipment, greater federal support through Farm Bill conservation programs, and pricing policies that generate funds that can be invested in local farms.

2 Comments on “Add Precision To Irrigation Water Use”

Comments are closed.