A number of measures exist that may potentially reduce the use of publicly supplied water. These can be broadly grouped into the categories of water saving devices; greywater re-use; rainwater harvesting and the efficient use of water in gardens and parks; leakage reduction; behavioural change through raising awareness; water pricing; and metering. Since treating, pumping and heating water consumes significant amounts of energy, using less publicly supplied water also reduces energy consumption (13).
In Denmark and Estonia, for example, a steady rise in the price of water since the early 1990s has resulted in a significant decline in household water use. Metering leads to reduced water use; in England and Wales, for example, people living in metered properties use, on average, 13% less water than those in unmetered homes (15).
Desalination increases the total available freshwater resource and, in this respect, may be preferable to further depletion of the surface and groundwater stocks. Detrimental environmental impacts are associated with desalination plants, however, in particular their energy consumption and the production of highly concentrated brine that may be released into sensitive marine waters. Furthermore, expanding supply from desalination plants does not provide any incentive to either reduce water use or improve the efficiency of use. Decisions on the suitability of future desalination plants need to be addressed on a case-by-case basis, accounting for all environmental and economic issues