Center-pivot irrigation with water-saving dropped nozzles on wheat growing in Yuma County, Colo., 1987. Source: USDA Natural Resources Conservation Service
By C.-Y. Cynthia Lin
Groundwater and water conservation are critical issues in California and globally. Many of the world’s most productive agricultural regions depend on groundwater and have experienced unsustainable declines in water levels.
In many places, policymakers have attempted to decrease groundwater extraction through voluntary, incentive-based conservation programs for irrigated agriculture.
These policies are often billed as policies where everyone gains. They are politically feasible. Farmers can install or upgrade irrigation systems at a reduced cost. Less groundwater is nominally “wasted” through runoff and evaporation.
However, such conservation policies can have unintended, even perverse, consequences.
Economist Lisa Pfeiffer and I found this to be the case in a recent UC Davis study of government programs to reduce groundwater pumping in western Kansas.
In response to rapid depletion of the High Plains Aquifer, the state subsidized a widespread conversion to more efficient irrigation technology in the late 1990s through mid-2000s. Programs paid up to 75 percent of the cost of upgrading or installing new irrigation technology – primarily “dropped nozzles,” which attach to center-pivot irrigators and reduce the amount of water lost to evaporation and drift.
“Dropped nozzles” hang right above crop, reducing water lost to evaporation and drift. Source: USDA, Natural Resources Conservation Service
But after making the shift to dropped nozzles, farmers ended up applying more groundwater to fields – completely negating the conservation intent.
Rather than reducing consumption, many farmers used their efficiency “savings” to expand irrigation into poorer soils or grow thirstier higher-value crops such as corn, alfalfa and soybeans. Greater irrigation efficiency increased overall water use.
Our findings, cited earlier this year in The New York Times, are counterintuitive but not surprising given the economics of irrigation.
Irrigation allows the production of higher-value crops on previously marginal land. More efficient irrigation increases the amount of water the crop receives per unit pumped from the ground. Thus, subsidizing more efficient irrigation makes more water available and induces irrigation of more land and the planting of more water-intensive crops.
Similarly, our field data show almost no effect of land conservation programs on groundwater pumping. Measures such as the federal Conservation Reserve Program pay growers and ranchers to retire, leave fallow or dry farm their land. Theoretically, because these programs are voluntary, farmers will enroll their least productive land.
There is substantial evidence that farmers do enroll their least productive lands in the programs, while pocketing government payments higher than the lands’ profitability. It is unlikely that irrigated parcels – a big investment to enhance productivity – would be among the low profitability plots that farmers enroll in the programs. So enrolled lands are unlikely to reduce groundwater pumping.
William Stanley Jevons, British economist, 1835 – 1882. Source: Wikimedia Commons
The responses we observed among farmers participating in the groundwater conservation programs are hardly new. In 1865, the English economist William Stanley Jevons postulated that the invention of a technology that enhances the efficiency of using a natural resource does not necessarily lead to less consumption of that resource. He found this to be true with the use of coal in a wide range of industries. Economists today refer to this idea as the “Jevons’ Paradox” or “the rebound effect.”
Policymakers need to be wary of the potential perverse consequences of conservation measures under development. Incentive-based groundwater conservation programs are a prime example of a well-intentioned policy gone awry.
C.-Y. Cynthia Lin an associate professor in the departments of Agricultural and Resource Economics and Environmental Science and Policy at UC Davis.
Further reading:
Jevons, W. S. (1865). The Coal Question. London: Macmillan and Co.
Fleck, John. (2013). Jevons’ Paradox of Christmas Lights, Jfleck at Inkstain, 17 Jan. 2013.
Lund, J., E. Hanak, R. Howitt, A. Dinar, B. Gray, J. Mount, P. Moyle, B. Thompson (2011), “Taking agricultural conservation seriously,” CaliforniaWaterBlog.com, 15 March 2011.
Pfeiffer, L., and Lin, C.-Y.C. (2013). Does efficient irrigation technology lead to reduced groundwater extraction?: Empirical evidence. Working paper, University of California at Davis.
Wines, Michael (2013). “Wells dry, fertile plains turn to dust,” New York Times, 19 May 2013.
Unfortunately, in this example, the state-subsidized higher efficiency irrigation equipment only made it cheaper to use the same amount (or more) of water over more land. Kansas distorted the economics of the situation in the wrong direction, and the result was continued high usage of the diminishing High Plains Aquifer. No surprise there.
The assumption that Jevons’ Paradox is shown here as a complete picture of the behavioral calculations and water use by farmers is not a sufficient explanation of what happened.
A truer picture of the impacts of the introduction of new efficiencies would be demonstrated if the externalized costs of supplying additional or replacement water from a depleted aquifer were included. As the High Plains Aquifer (or Ogalalla or other ground water) is depleted, the costs for supplying additional or replacement water go up – way up. Those costs – likely at least an order of magnitude higher than current costs – would be the real driver of the use of higher efficiency in irrigation.
As is true for additional water supply, or electrical supply or other limited resources, when the true costs of obtaining, delivering, generating or otherwise finding and delivering the next increment is included in the calculation, efficiencies will be used. Efficiencies will then be cheaper than finding and delivering more water of at least the same quality.
As long as the true, externalized costs of water are obscured or not included, the market remains dysfunctional and seriously distorted, and the behavior isn’t significantly changed.
Pingback: Science news and reports: New research on mercury, toxic algal blooms,steelhead trout, affordable water bills, climate change, building condos for fish and more! » MAVEN'S NOTEBOOK | MAVEN'S NOTEBOOK
I’m sorry but this is a misrepresentation/misinterpretation of what is going on. You imply that efforts to improve efficiency are misguided. But you mistake efficiency and “productivity.” You criticize such efforts done without any related policy decisions about water rights or reallocation as though it is the fault of farmers who make the logical choice (in the absence of an agreement to give up or reallocate water) to simply do more with less. This is not the fault of efficiency efforts. This is the fault of efficiency efforts WITHOUT accompanying policy prescriptions.
Unless these efforts, done (as you say) to reduce groundwater overdraft, are accompanied by explicit required reductions in withdrawals, then it is a POLICY failure, not the failure of technical efficiency efforts.
Perhaps this is what you mean, but the way this is written, it implies (and the media reads it and reports on it as though) efficiency efforts themselves are bad.
We address this explicitly in the journal article found here:
http://www.pacinst.org/publication/water-use-efficiency-and-productivity-rethinking-the-basin-approach/
The commenters seem to violently agree with the author. It has taken many years for some water use efficiency advocates to understand this more nuanced view of efficiency.
Alas, in agriculture, large reductions in net water use commonly (but not always) require reductions in crop production. As a colleague once put it, “Agriculture is an evapotranspiration business.”
There can be other benefits to improving the localized efficiency of water use, such as improving water quality in some cases, but there are also costs.
“Efficiencies” which are not effective in achieving environmental and economic objectives are not actual efficiencies at all. Worse yet, such false efficiencies can distract us from more effective actions.
The author has done us all a great service of reminding us what is needed for actual efficiencies to occur.
Pingback: The ag irrigation efficiency paradox : jfleck at inkstain
This is an interesting article. But, it left a massive gap in information, and I was left wondering, “So, what exactly needs to occur to ensure that water conservation efforts are not wasted, or even exploited, resulting in unintended extravagant water use?” Certainly, the article cannot be insinuating that water conservation efforts are a bad thing in and of themselves, right? Of course not. Then I read the commenter’s post:
“Unless these efforts, done (as you say) to reduce groundwater overdraft, are accompanied by explicit required reductions in withdrawals, then it is a POLICY failure, not the failure of technical efficiency efforts.”
Now it makes sense. Thank you, Dr. Gleick, for filling in the missing piece that the article should have included. I plan on reading the article that you linked to.
Reblogged this on NewsBeat: UC Davis College of Agricultural and Environmental Sciences.
Pingback: The Cal Water Blog: Irrigation Efficiency Increases Ground Water Use | California Central Valley Water Blog
Rising irrigation efficiency is certainly not a black-and-white issue: a change in irrigation efficiency is a major technological change that reorganizes the water flows in the basin, their quality and, consequently, their value for the farmers and the society. All these consequences should be assessed and the interest of switching to higher efficiency is highly context dependant.
Groundwater may be the main exception where the usual explanation of the Jevons paradox applies: higher irrigation efficiency reduces the cost of water for the farmer, which can lead to more water use, since cheaper water allows a higher demand to be satisfied.
Groundwater is an exception because the common situation in the world (for surface water) is that the amount of water applied by farmers is not constrained by water price but other factors such as quotas or physical scarcity. In this case, the explanation of the Jevons paradox (based on cost/price) does not hold.
Another problem with the Jevons paradox is that it implies that water savings can effectively be obtained when adequate policies are established (Dr. P. Gleick says the same), while in many cases, much part of the water “saved” would have been available for other users downstream anyway (percolation in the “inefficient” system). The use of water may be more productive after efficiency improvement (not sure if the energy costs of a drip system are integrated) but it is definitely hard to prevent an increase in CONSUMPTIVE water use.
More details in our recently published paper (open access): “Is the Rebound Effect or Jevons Paradox a Useful Concept for better Management of Water Resources? Insights from the Irrigation Modernisation Process in Spain”
http://www.sciencedirect.com/science/article/pii/S2214241X13000072#
Well, it is context-dependent. In many of parts of Tamil Nadu, where farmers are taking to coconut crop in a big way due to problems such as increase in labour scarcity and wage rates, the introduction of drip irrigation for water saving has resulted in acceleration in coconut area expansion. A farmer who could have planted one acre of coconut, planted two or more, because of additional water available due to drip system. And also the farmers took acreage decisions based on groundwater availability and rainfall quantum in normal years.
During the last two years of drought, when the groundwater levels dropped and coconut trees started withering, there has been a large scale effort to drill deeper and deeper bore-wells, thus pushing the water levels down. This process has been further aggravated by the fully subsidized electricity supply for agriculture. So, no matter how little is the water yield of bore-wells, it always makes sense for the individual farmer to dig deeper and deeper in search of whatever little quantum of groundwater that is available. Free electricity together with electrically operated compressors have come in handy for the farmers to pump even very little quantities of water.
As a coconut farmer I am pumping water from a recently-dug borewell of 700 feet depth. The water yield is only 4 to 5 litres per minute but still it makes sense for me because electricity is free and the cost of coconut plantation and the cost of bore-well have already become sunk costs. If the drip systems were used on seasonal crops, the story would have been different. But because farmers have established coconut plantations with substantial initial investments, they are under the compulsion to “save” these plantations at any “cost” — private costs of drilling bore-wells and social costs of electricity, groundwater over-exploitation, and the associated intra- and inter-generational externalities. The rampant expansion in bore-wells associated with the huge expansion in coconut area and drip irrigation is a clear case of policy failure. Such a steep increase number and depth of bore-well has not happened in other parts of the state where coconut has not been expanded in a big way.