When a recent drought dangerously reduced available water, California set up a voluntary water bank that purchased water from farmers and sold it to urban areas. The farmers made a profit by selling water for more than it was worth to them, while the cities got water at a cost well below that of other sources of supply. In the 1960s the government of the USA concluded that sixteen dams and more than US$ 400 million were required to meet the water needs of Washington DC. Environmental pressure forced plans to be reconsidered. The number of dams was reduced to one at a total cost of US$ 30 million. The key changes were a revised plan for managing demand during droughts and more efficient operating rules. Also in the USA, manufacturing industry freshwater withdrawals are estimated to be 62% less in 2000 than in 1977, primarily because of the increased costs industries have to pay for disposing of industrial wastewater.
The city of Jakarta, Indonesia, has had success in reducing overpumping of its aquifers by registering groundwater users and introducing a groundwater levy. In Sao Paolo, Brazil, three industrial plants reduced their water demand by between 42 and 62% as a result of the imposition of effluent charges.
UNESCO's programme includes the following: evaluating the impacts of global and regional climate changes on water resources; improving scientific understanding of water-related issues and sustainable water resource management in the humid tropics; strengthening member states' capabilities in the preparation of water-resource master plans.