Twentieth-century water policies were largely dominated by the construction of massive water extraction, storage and transport infrastructure, which brought benefits, such as the expansion of irrigated agriculture in deserts, but at substantial environmental costs (Gleick 2003), as illustrated by the examples of the Aral Basin in Central Asia and the Imperial Valley in the southwestern United States (see Chapter 5).

Analogous to the "soft path" for energy policy advocated by Lovins (1976), leading water experts strongly promote a "soft path" for water development in response to the impending global water problems (Gleick 2003; Rijsberman 2004). This soft path should focus on water-use efficiency and the control of demand rather than building ever bigger dams and endlessly developing new sources of water. Deserts, as the first environments confronted with water shortages and forced to rethink water use priorities, should be among the forerunners in developing and testing innovative, and globally relevant, technologies and policies.

The implementation of water conservation measures and improvements in water-use efficiencies needs to be supported by economic and institutional structures. In many desert regions, water prices currently do not reflect the value of water. A strategy to discourage wasteful water consumption, which at the same time contributes to more equitable access to water, is to support low-income and low-volume users with transparent subsidies, financed by excessive water consumers. Raising public awareness about the need to conserve water is particularly important for new migrants into deserts who have not developed a "sense of place", such as those moving into the desert cities of the American Southwest.

Small-scale decentralized water supply facilities and the involvement of communities in the decision-making process about water management, allocation and use ensure more equitable access to water and potentially lower environmental impacts than the massive centrallyplanned water schemes of the 20th century (Gleick 2003). In the communal parts of Namibia, for example, water point committees have been set up as part of a larger decentralization policy, which are responsible for the provision of water to the community and the maintenance of communal water installations (Werner 2000).

Promotion of only high value-added uses of water can improve water efficiency: for example, the high-tech industrial sector enhances the value of each cubic metre of water used many times more than the agricultural sector (Gleick 2001). Within the agricultural sector, one possibility to improve water efficiency is to restrict irrigated agriculture in deserts to high-value crops (for example, dates) or aquaculture (see Chapter 3), whereas lower value crops (for example, maize) can be imported from regions better endowed with water. Despite the risks involved with abandoning their food independence, many water-poor countries already choose to import food rather than growing it, creating a virtual flow of water, which is contained in the imported food products or other commodities that require high water inputs. With increasing globalization, the import of "virtual water" becomes a tool in waterresource management, which can be used to relieve pressure on scarce water resources in deserts.