Keeping It Down on the Farm: Agricultural Water Use Efficiency
March/April 2012
There are two constants regarding agricultural water use – growers will continue to come up with ever more efficient and innovative ways to use water and they will always be pressed to do more.
It’s safe to say the matter will not be settled anytime soon, given all the complexities that are a part of the water use picture today. While officials and stakeholders grapple to find a lasting solution to California’s water problems that balances environmental and economic needs, those who grow food and fiber for a living do so amid a host of challenges.
Introduction
There are two constants regarding agricultural water use – growers will continue to come up with ever more efficient and innovative ways to use water and they will always be pressed to do more.
It’s safe to say the matter will not be settled anytime soon, given all the complexities that are a part of the water use picture today. While officials and stakeholders grapple to find a lasting solution to California’s water problems that balances environmental and economic needs, those who grow food and fiber for a living do so amid a host of challenges.
One of those challenges is water supply, never a sure proposition for anybody in agriculture because of the vagaries of drought, regulatory compliance and water rights priority. Farmers have responded with a multitude of tools that enable them to surpass old production targets using the same amount of water, or less.
All the while, the drumbeat continues for less water use on the farm. The drive picked up momentum with the Water Conservation Act of 2009, a major piece of legislation that requires large agricultural water suppliers to measure the volume of water delivered to customers with increased accuracy, adopt a pricing structure for water customers that rewards them for using less water and quantify water use efficiency from the basin to the farm level.
While a product of the political process, the implications of the law are that all users need to be constantly aware of the value of the resource and constantly striving for conservation. “Water use efficiency is an important element of our future,” said Manucher Alemi, chief of the Department of Water Resources’ (DWR) Office of Water Use and Efficiency, at the Water Education Foundation’s “Water 101” Feb. 23 seminar in Davis.
Better water use efficiency in the agricultural sector is imperative because of the existing constraints and uncertainty surrounding future water deliveries from the Central Valley Project and the State Water Project, Alemi said, noting it is likely “there will be more restrictions and more regulations on the use of those facilities.”
Environmental groups and other non-government organizations say their aim is not to create new water but for agriculture to better deal with water scarcity while realizing improved crop yields and water quality as well as energy savings.
Some scientists say it is a misconception that a huge supply of available water could be made by improving on-farm efficiency. “Claims that California farmers are wasteful and inefficient when it comes to managing their water supplies are inaccurate,” according to Agricultural Water Use in California, A 2011 Update, a report by Pete Canessa, Sarge Green and David Zoldoske with the Center for Irrigation Technology (CIT) at California State University, Fresno. “Despite assertions by some, large volumes of ‘new water’ available through agricultural water conservation do not exist.”
Determining how much of the water applied to fields and orchards is beneficially used is a nettlesome proposition that should instead be viewed from the larger perspective of “how much water does the crop need plus how much does the environment need plus how much for [soil enhancement] uses and are there ways to reduce those uses,” said Doug Obegi, staff attorney with the Natural Resources Defense Council (NRDC).
At a time when instream flows and the future of California’s water conveyance are discussed so prominently, agricultural water use is a key part of the conversation, including crop selection and irrigation methods.
“Water use efficiency means different things to different people,” said John Gates, an assistant professor with the Department of Earth and Atmospheric Sciences at the University of Nebraska-Lincoln. “For example, the common definition of water use efficiency from an irrigator’s perspective is ‘crop per drop,’ or amount of crop yield per amount of water applied to the field. In this definition, irrigation return flow is considered an inefficiency because it took resources to acquire some amount of water that ultimately did not contribute to yields.
“But from a watershed manager’s perspective, irrigation return flow is not an inefficiency because that water returns to the watershed for future use or environmental flows. In contrast, both the irrigator and the watershed manager would consider evaporation from the soil an inefficiency. This is just one example where differing perspectives on efficiency can lead to some confusion.”
Agriculture has seen “significant advancement” in irrigation efficiency during the past 20 years and “it is not difficult to find state-of-the-art irrigation systems in most areas of the state,” said Lester Snow, former DWR director. While “more can be done,” it is at “a very site-specific determination” that accounts for many factors.
“Agriculture is not a monolith and efficient irrigation depends on the crop being grown, the soil type and the geographic location,” said Snow, who now serves as director of integrated resource management with the Resources Law Group in Sacramento. “The irrigation system that is the most efficient to grow the best tomato crop on the west side of the San Joaquin Valley has no applicability to growing rice in the Sacramento Valley or avocados in northern San Diego County.”
This issue of Western Water examines agricultural water use – its successes, the planned state regulation to quantify its efficiency and the potential for greater savings.
NOTE: Click here to purchase a copy of the entire article.
Editor’s Desk
“The philosophy of the schoolroom in one generation will be the philosophy of the government in the next,” said President Abraham Lincoln. Our school education program, Project WET – Water Education for Teachers – is built on this wise statement. In the classroom, the program promotes responsible stewardship of natural resources that will lead these students – as adults – to make good water resource decisions. Project WET is now over 15 years old and has reached 14,374 teachers and over 4.5 million students! This is impressive because it means that those teachers have participated in at least six hours of training on the use of Project WET activities to support the teaching of California Content Standards, STEM (Science, Technology, Engineering and Math) initiatives and the National Common Core Standards for Math and Language Arts skills.
Brian Brown, the California Project WET Coordinator, coordinates with partners to offer low cost – or free – workshops for K-14 teachers. These partners are water agencies, water research scientists, science method professors and teachers, after school program directors, and state environmental education coordinators. Project WET training meets their need for high quality professional development. One of the points that makes Project WET successful is that the activities are fun while incorporating nationally recognized education principles and practices. The activities are developed by teachers for teachers. As a parent of a former public school student, I know that teachers are over loaded with responsibilities. So any organization wishing to influence public school students cannot give the teachers more work! Successful school education programs have to help the teacher meet the necessary teacher requirements. Additionally, Project WET activities use low cost materials – a help to teachers who often use their own money for activities. And Project WET provides step-by-step instructions making the activities very popular with educators of all levels of teaching experiences.
Local water resource issues can be easily integrated into the WET program and activities. Some of the recent workshops have been tailored specifically to highlight local water issues including: nonpoint source pollution, stormwater runoff, water conservation, water treatment and watershed management. Our national partners help us fund our state’s Project WET program. In partnership with the U.S. Geological Survey (USGS), the program offers workshops highlighting the role of science in studying subjects ranging from groundwater issues in the Coachella Valley to water issues in the California Delta. Major funding also comes from the Bureau of Reclamation, Mid-Pacific Region, to support conservation and water quality and the California Department of Water Resources to support water education initiates throughout the state.
If you would like to learn how you or your organization can get involved with Project WET and set up a workshop, contact Brian Brown at the Foundation, projectwet@watereducation.org