In the 1970s the US faced a serious shock to the supply of oil but the shortage of oil was caused by price controls. Today, California is facing a serious water drought but the shortage of water is caused by price controls, subsidies and the lack of water markets. In an excellent column, The Risks of Cheap Water, Eduardo Porter writes:

Water is far too cheap across most American cities and towns. But what’s worse is the way the United States quenches the thirst of farmers, who account for 80 percent of the nation’s water consumption and for whom water costs virtually nothing….

Farmers in California’s Imperial Irrigation District pay $20 per acre-foot, less than a tenth of what it can cost in San Diego….This kind of arrangement helps explain why about half the 60 million acres of irrigated land in the United States use flood irrigation, just flooding the fields with water, which is about as wasteful a method as there is.

Tyler and I discuss water subsidies in Modern Principles:

Farmers use the subsidized water to transform desert into prime agricultural

land. But turning a California desert into cropland makes about as much sense

as building greenhouses in Alaska! America already has plenty of land on which

cotton can be grown cheaply. Spending billions of dollars to dam rivers and

transport water hundreds of miles to grow a crop that can be grown more cheaply

in Georgia is a waste of resources, a deadweight loss. The water used to grow California cotton, for example, has much higher value producing silicon chips in

San Jose or as drinking water in Los Angeles than it does as irrigation water.

The waste of subsidized water is compounded by over 100 years of rent-seeking and a resulting legal morass that makes trading water extremely difficult (see Aquanomics for a good analysis). A water trading system is slowly taking form in the American West but the political transaction costs are immense. Australia, however, faced similar difficulties but has managed to develop a good water trading system and Chile has long had a robust market in water. Subsidies to farmers are politically sustainable when everyone has as much water as they want but when faced with continued shortages and an ever-intrusive water Stasi consumers and industry may eventually demand a more rational, less wasteful system based on incentives, markets and prices.