Water Risk Hotspots for Agriculture: The Case of the Southwest United States
Published: September 22, 2016
Authors: Heather Cooley, Michael Cohen, Rapichan Phurisamban, and Guillaume Gruère
Despite being the United States’ most arid region, the US Southwest – Arizona, California, Colorado, Nevada, New Mexico, and Utah – is one of the most productive agricultural regions in the world. Yet nearly 75% of total cropland in the region, and an even higher percentage of total agricultural productivity, depends on supplemental irrigation. Meanwhile, climate change and increased water demand are putting pressure on the region’s limited water supplies and raising concerns about the viability of agriculture in the region.
The Pacific Institute, in coordination with the Organisation for Economic Co-operation and Development (OECD), recently completed a case study on the possible impacts of future water risks on agriculture in the US Southwest by mid-century. The report finds that while the Southwest will likely continue to be a major agricultural producer for the next 50 years, it will be impacted by more variable and uncertain water supplies and increased water demand. Additionally, total irrigated area is likely to decline due to limits on water supplies and urban encroachment, with lower value, water-intensive field and forage crops likely to experience the greatest reductions.
Livestock and dairy are economically important to Southwest agriculture and are especially vulnerable to water shortages and climate change. Feed prices are likely to rise, thereby increasing costs for producers, while climate change is likely to alter the location and productivity of pasture and rangeland, the distribution of livestock parasites and pathogens, and the thermal environment of animals. Trade and employment may also be affected, although projections remain uncertain.
These projected changes will be less disruptive if meaningful steps are taken to mitigate economic losses, protect ecosystems, and invest in productive strategies, and the report provides several key recommendations: increasing urban water-use efficiency to reduce the pressure to take water from agriculture; increasing agricultural water-use efficiency to help maximize the productivity of limited water resources; and shifting from higher water-use to lower water-use crops to keep agricultural land in production with less total water demand.
Additionally, improving groundwater management and developing water banks can reduce vulnerability to more variable surface water supplies, while the use of recycled wastewater could be expanded, especially close to urban areas. Lastly, water transfers can also play a role, although they must be conducted within a clearly defined system, have explicit goals, and acknowledge and adequately mitigate possible adverse impacts.
Download the report here.