No abstract

Deteriorated cast iron pipes often account for a significant portion of water main failures in a water distribution network. Such incidents cause havoc to traffic circulation, damage surrounding properties and public infrastructure, and increase the risk of water contamination. Thus, infrastructure managers often receive questions from stakeholders concerning the replacement time horizon of such pipes and the associated financial investment needs. These questions are difficult to answer as the service lifetime of buried pipes depends on a number of factors such as the rate of deterioration, the associated failure risk, the level of risk tolerance of the utility as well as the intervention planning activities of other utility networks. In addition, replacement costs depend on economies of scale as the unit cost of pipe replacement tends to decrease as length increases. Managers must consider these factors along with associated uncertainty when making estimates on replacement projections of problematic pipes. In this paper, a methodology is presented that aims to help infrastructure managers make accurate pipe replacement projections. An example is provided of the implementation on a large water distribution network.