Hydraulic Models Support Renewal and Replacement Programs

Those who live in developed countries are accustomed to having safe water instantly available at the tap, so they rarely think about the infrastructure needed to bring it to their homes until there is a service interruption. In the water industry, service expectations for utilities are often defined as “service levels” and generally include metrics for how systems should perform. Fire-flow volumes, minimum and maximum service pressures, and allowable pipe velocities are examples of measurable system performance criteria that can be determined through field verification or hydraulic modeling.

As water mains age, failures become more frequent, and maintaining service levels becomes increasingly challenging. Utilities must have actionable plans and funding in place to rehabilitate or replace infrastructure to continually meet customer expectations. If a utility waits too long to develop a pipe management program, it may find its maintenance activities are primarily reactive rather than proactive. Reactive maintenance is symptomatic of a less reliable system and ultimately may result in higher operational costs for a lower level of service. Over time, every community needs to replace its aging infrastructure, particularly water mains. This article analyzes risk-based approaches to renewal and replacement strategies and how hydraulic modeling can be used to support risk-based asset renewal programs.