Water desalination has been supported since 1983 by the Spanish Government to obtain a price of drinking water similar to the average price of water used by households in all of Spain. The support was calculated according to many factors such as the cost of water production (m(-3) Euro), energy consumption (kWh m(-3)), quantity of desalinated introduced in the supply network (m y(-1)), and population density (inh km(-2)) from 1983 to 1996. In 1997, according to advances in the economics system undertaken by the Spanish Government, the formula was simplified to take into account only water production and management. In regions with strong water scarcity such as the Canary Islands, subvention for water desalination was calculated following the hydraulic system efficiency of each concession company. Since 1997, the difference of water market prices between the Canary Islands and the rest of Spain has been practically constant at 0.87 m(-3) Euro. The water desalination industry has had a sustainable growth due to price controls in Spain.