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.

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.

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.