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226 The term virtual water was coined by J. A. Allan in the early 1990s, e.g., “Policy Responses to the Closure of Water Resources,” in Water Policy: Allocation and Management in Practice , P. Howsam, R. Carter, eds. (London: Chapman and Hall, 1996).

227 The global transfer of virtual water embedded within commodities is estimated at 1,625 billion cubic meters per year, about 40% of total human water consumption. A. K. Chapagain, A. Y. Hoekstra, “The Global Component of Freshwater Demand and Supply: An Assessment of Virtual Water Flows between Nations as a Result of Trade in Agricultural and Industrial Products,” Water International 33, no. 1 (2008): 19-32. See also pp. 35 and 98, UN World Water Assessment Programme, The United Nations World Water Development Report 3: Water in a Changing World (Paris: UNESCO, and London: Earthscan, 2009), 318 pp.

228 R. G. Glennon, Water Follies: Groundwater Pumping and the Fate of America’s Fresh Waters (Washington, D.C.: Island Press, 2002), 314 pp. Windmills and other early technology could lift water from a maximum depth of only seventy to eighty feet, but the centrifugal pump, powered by diesel, natural gas, or electricity, could lift water from depths as great as three thousand feet.

229 Figure 7.6, UN World Water Assessment Programme, The United Nations World Water Development Report 3: Water in a Changing World (Paris: UNESCO, and London: Earthscan, 2009), 318 pp.

230 U.S. Geological Survey, “Estimated Use of Water in the United States in 2000,” USGS Circular 1268, February 2005.

231 Other materials can also make good aquifers, for example gravel or highly fractured bedrock.

232 See M. Rodell, I. Velicogna and J. S. Famiglietti, “Satellite-based Estimates of Groundwater Depletion in India,” Nature 460 (2009): 999-1002, DOI:10.1038/nature08238; and V. M. Tiwari, J. Wahr, and S. Swenson, “Dwindling Groundwater Resources in Northern India, from Satellite Gravity Observations,” Geophysical Research Letters 36 (2009), L18401, DOI:10.1029/2009GL039401.

233 Also known as the High Plains Aquifer, the Ogallala underlies parts of Kansas, Nebraska, Texas, Oklahoma, Colorado, New Mexico, Wyoming, and South Dakota. Other material in this section drawn from V. L. McGuire, “Changes in Water Levels and Storage in the High Plains Aquifer, Predevelopment to 2005,” U.S. Geological Society Fact Sheet 2007-3029, May 2007.

234 Human drawdown averages around one foot per year, but natural replenishment is less than an inch per year. Telephone interview with Kevin Mulligan, April 21, 2009.

235 “Useful lifetime” is projected time left until the saturated aquifer thickness falls to just thirty feet. When the aquifer is thinner than thirty feet, conventional wells start sucking air, owing to a thirty-foot cone of depression that forms in the water table around the borehole. The described GIS data and useful lifetime maps for the Ogallala are found at http://www.gis.ttu.edu/OgallalaAquiferMaps/.

236 LEPA drip irrigation systems create a smaller cone of depression, allowing water to be sucked from the last thirty feet of remaining aquifer saturated thickness. Therefore a switch to LEPA can prolong the usable aquifer lifetime another ten to twenty years, but cannot stop the outcome.

237 Notably the Netherlands, France, Germany, and Austria. P. H. Gleick, “Water and Energy,” Annual Review of Energy and the Environment 19 (1994): 267-299. This is not to say all of the water used is irrevocably lost; most power plants return most of the heated water back to the originating river or lake. See note 225 for withdrawal vs. consumption.

238 This is the legal maximum in the European Union, but recommended “guideline” temperatures are lower, around 12-15 degrees Celsius in the EU and Canada. Ibid.

239 See also his book on wind power. M. Pasqualetti, P. Gipe, R. Righter, Wind Power in View: Energy Landscapes in a Crowded World (San Diego: Academic Press, 2002), 248 pp.

240 The reason for this is the very large water losses that evaporate from the open