ABSTRACT
Water managers are entrusted with the responsibility of overseeing the operation and maintenance of water distribution networks to ensure that the public continually has access to a reliable source of high quality potable water in sufficient quantity and at a reasonable price. With time and usage, water infrastructure deteriorates, resulting in lower levels of provided service and an increased risk of failure. Hence, water managers must determine the interventions to be executed on the network and subsequently coordinate these optimally with other utilities/stakeholders to minimize impacts to the public and take advantage of cost-saving opportunities (i.e. replacement of other infrastructure networks). This is a difficult task due to the extent of such networks, the variety of objects present (e.g. pipes, pumps, valves, etc.) and the considerable level of information uncertainty. These factors lead managers to rely on intuition and expert knowledge to make important investment decisions. This is not ideal as expert knowledge can be prone to bias, the knowledge transfer between experienced and inexperienced water managers is not perfect, and decisions can be made, which are non-transparent to all stakeholders. In order for objective decision-making, costs and benefits of executing interventions must be defined and calculated for the intervention planning period. In this paper, a method for conducting cost-benefit analyses is presented for water infrastructure investment decision-making. An example of the implementation is shown for a large water distribution network consisting of both underground pipes and facility objects. A discussion is provided of how this can be used in investment decision-making.
