protecting water resources directly at the source by limiting pollution from catchments also generates indirect benefits such as avoided investment and treatment costs and can be overall more costeffective increasingly countries are recognising the benefits of managing water resources using a whole of basin or river basin approach given that reducing pollution at the source tends to be a cheaper option than treating water before supplying it to consumers the degree of certainty with which water is supplied is an important factor in determining the benefit that water users derive from the service and strongly influences their willingnesstopay increased reliability of water supplies avoids the need for households to store water for shortage situations and therefore induces cost savings water reliability is also an important parameter for economic activities industries but also agriculture and services which use water in their processes or as a nonsubstitutable input benefits from wss investments are not equally shared amongst users whereas benefits from water services are usually experienced at household level benefits from sewerage services are shared by a community as a whole