Phoenix Water Services Department forecasts the City of Phoenix will need to spend approximately $20.5B over the next 75 years.
The estimate comes from more than 12,100 miles of water/sewer pipeline that must be rehabilitated or replaced.
Water and sewer pipelines have an average life expectancy of 75 years, with many of Phoenix’s pipelines nearing the expiration date.
A pipeline is usually considered at the end of its useful life when operation costs are too high or if the impact of breaks become “unacceptable”.
Approximately 41% of the City’s pipelines were built between 1950 and 1980. Many of those pipes are anticipated to age out between 2025 and 2055. This will lead to an influx of pipes needing attention in the earlier portion of the 75-year Water Services Department forecast.
The Water Services Department is trying to figure out the optimal way to spread out infrastructure costs to keep water rates affordable for residents. Bonds are a potential method the City can use to fund the infrastructure improvements.
Assessing the pipes will give the Department priorities. Once priorities are set, projects will be planned in neighborhoods to address multiple mains at once. This typically occurs on a half-mile grid.
Assessments occur every eight-10 years, leading to the pipes being rated on a nationally standardized system.
Previously, pipes were dug up for repairs/replacement. Now the pipes are often simply lined with new material, lowering costs and traffic disruptions. (Source)