Water and Agriculture: Irrigation Geography

Agriculture is by a wide margin the largest consumer of the world's freshwater, accounting for approximately 70% of global freshwater withdrawals according to the FAO's AQUASTAT database, a share that rises even higher in arid, agriculture-dependent economies such as Pakistan and Uzbekistan, where irrigation can account for 90% or more of total withdrawal. In the United States, California's Central Valley exemplifies large-scale engineered irrigation geography: a combination of the federal Central Valley Project, authorized in 1933, and California's own State Water Project, begun in the 1960s, moves water hundreds of kilometers via canals and aqueducts from the wetter north of the state to the arid but highly fertile south, sustaining a region that produces a substantial share of the fruits, vegetables, and nuts consumed in the United States despite receiving relatively little natural rainfall.