By Jay Lund
There has been considerable kvetching during this drought about California exporting agricultural products overseas, with some saying that this implies we are virtually exporting water that we should be using in California.
Those concerned should take comfort with California’s major imports of virtual water. Much of the food consumed here comes from other states and countries, and their production, of course, requires water.
Much of the corn fed to California’s dairy cattle is grown on Midwest farms with Midwest water. And much of our clothing is made of imported cotton, a water-intensive crop, or made from petrochemicals, which used oil and water from elsewhere.
Tremendous amounts of water also is needed to grow Oregon’s forests that supply a lot of the lumber framing our new homes, to produce the steel in cars shipped to California and to run factories in China and Malaysia that make our computers and smart phones. Think of the virtual water all these other countries and states are exporting to us.
We live in a world of virtual flows of goods and services that produce the real goods and services we willingly buy in favor of less-efficiently made local goods and services. The economics of production are important – virtual water is not.
The virtual water notion can be applied to other production inputs. Consider California’s many virtual immigrants — people who did not need to move here because we import the products they make in other states and countries. Consider virtual energy use; some of the energy used to make your iPhone came from Iran via China, virtually avoiding trade sanctions with Iran.
“Virtual water” and related “water footprint” calculations are cute and popular. We can have lots of fun with the idea of a virtual this and that. (Virtual manure can be imagined coming and going from California and flowing globally.) These notions have some value for raising public consciousness on the roles and importance of water. But the wide range of water values and opportunity costs across the globe and over time commonly makes these calculations misleading.
Talk of virtual water distracts from serious discussion of economic, environmental and hydrological objectives and processes important for real water and environmental systems to function. Virtual water discussions are all the more counterproductive coming in the midst of a very real and serious drought.
Jay Lund is a professor of civil and environmental engineering and director of the Center for Watershed Sciences at UC Davis.
Frontier Economics (2008), The concept of ‘virtual water’ — a critical review, Report for the Victorian Department of Primary Industries, Australia.
Iyer, R.R. (2012), Virtual water: Some reservations, GWF Discussion Paper 1218, Global Water Forum, Canberra, Australia.
Merrett, Stephen W. (2003), ‘Virtual water’ and Occam’s razor, Occasional Paper No 62, SOAS Water Issues Study Group, School of Oriental and African Studies/King’s College London, University of London.
Neubert, Susanne (2008), “Strategic Virtual Water Trade – A Critical Analysis of the Debate,” in W. Scheumann et al. (eds.), Water Politics and Development Cooperation, 123 doi: 10.1007/978-3-540-6707-76, Springer-Verlag, Heidelberg 2008
Wichelns, Dennis (2010), Virtual Water and Water Footprints Offer Limited Insight Regarding Important Policy Questions, Water Resources Development, Vol. 26, No. 4, 639–651, December.
Save the Date
Drought Science, Policy and Management Summit
University of California
April 25, 2014
8:30 a.m. to 4:30 p.m.
Free and Open to the Public
Unless the next two months are extraordinarily wet, 2014 will be a drought year. There is increasing attention on water supply problems for farms, cities, fish and wildlife. California’s history is punctuated by short and long droughts, and climate change portends a water-short future for the state. California’s institutions of higher education have long provided insights and scientific information on droughts and water management for policymaking and management. Conversations on drought and long-term water management seem especially timely.
This event will bring together a wide range of experts from across the state for thoughtful discussion of California’s drought and water supply issues. Experts will engage with water managers and policymakers on how best to manage current and long-term water shortages. Topics range from agricultural production and employment to wildfires, public health and welfare, the economy, energy production and use, fish and wildlife, and water conservation.
The event will include a review on what university campuses are doing to conserve water and provide water-saving advice for residents, farmers and business owners.
The Center for Watershed Sciences at UC Davis is organizing faculty from all UC campuses and others to help plan the daylong summit with a range of government, academic and other drought experts.
A preliminary program will be available soon.
- News Media: Patricia Bailey; Office: (530) 752-9843;
- Cell: (530) 219-9640; firstname.lastname@example.org
- Summit Planning: Amber Manfree, email@example.com
UC Drought Web Sites: