ABSTRACT
This chapter deals with water demand and the challenges of the water gap, which arises where there is a greater demand for water than available supply in the forms in which it is demanded. Demand for water grows because of demographic change, increased needs for agricultural produce, urbanisation and the supply of manufactured products. Water demand management planning requires ways of measuring demand. This chapter describes key features of demand estimation techniques, which involve large-scale resource inventories of groundwater and surface water, measuring usage rates and replenishment rates, and outlining forecasts of future demand. Managing water demand may require water resource development programmes (e.g. dam construction) in order to try to secure resources to meet demand. Increasingly, however, managing water demand involves technological solutions to drive more efficient use (and reuse) of water and also working with people to alter attitudes and behaviour so as to reduce water demand across agriculture, industry and domestic users.
