Analysing water use patterns for demand management: the case of the city of Masvingo, Zimbabwe

Water use in urban centres is dynamic, fluctuates, differs between high and low-income users, and tends to increase over time. Supply infrastructure can often hardly keep pace with increased water consumption. Given (a) the high cost of infrastructure development, (b) the recent emphasis on demand management, and (c) the social obligation to provide water services to the poor, urban water providers are faced with an important choice: whether to go the demand management route, or to continue constructing new infrastructure. This paper sheds light on some of the possibilities and constraints of both choices by providing a case study of the city of Masvingo in Zimbabwe. The paper analyses water use patterns in this city with a population of 70,000, located in a drought prone region of average rainfall of 600 mm/a. Water consumption has reached the limits of the water supply capacity. The paper first looks at the long-term water use pattern of the city as a whole and the factors that have caused the observed pattern using multiple linear regression. The paper then analyses the patterns of water use of rich and poor households, and attempts to assess the (im)possibilities of influencing these by means of an appropriate tariff structure. In projecting future demand, the paper then considers a number of interventions that could influence demand, which include leakage control, pressure management, awareness campaigns, free technical advice to water users, as well as a new tariff structure. It also discusses when new supply infrastructure should be available, depending on the various demand management measures taken.