Located in the heart of the Sonoran Desert, the City of Mesa, Arizona faces historic drought and increasingly hotter, drier conditions. To support sustainable water supplies for Mesa’s growing population, the City manages a rigorous pipeline inspection and replacement program. As a result, water loss from pipeline leaks and breaks is below the national average.
This program leverages advanced inspection technology to detect threats early and make timely repairs. Prioritizing high-risk assets and areas for inspection helps the City focus resources across one of the largest water distribution systems in the state.
Freeway crossings are among these high-risk areas. Pipelines running beneath freeways and other transportation infrastructure face heightened risks from heavy traffic loads and third-party construction. Pipeline leaks and failures can also have serious consequences for road integrity, traffic, and public safety.
Challenge
In December 2025, an inspector discovered water surfacing from an active water distribution main during construction of a new roadway connection on Ray Road in Mesa. The leak was located beneath a newly built overpass at the intersection of Ray Road and State Route 24, a critical commuter corridor carrying an average of over 60,000 vehicles daily.
The saturated subgrade and active leak brought the transportation project to a standstill. With multiple contractors involved, any prolonged shutdown risked significant daily costs and project delays.
Exposing the 16-inch main revealed water leaking from the end of a 900-foot steel casing. Casings are commonly used at freeway crossings to provide additional structural support and protection. However, the casing not only made traditional excavation impractical but also distorted sound, rendering aboveground acoustic leak detection ineffective. The City of Mesa needed a solution that would deliver results fast, even under difficult conditions.
SmartBall® is a pipeline inspection tool that uses acoustic technology to detect leaks.
Solution
The City’s Water Resources Department acted quickly to prevent major disruptions to the Ray Road improvement project. Drawing on their condition assessment experience and long-standing partnerships, they enlisted Xylem’s support to pinpoint the hard-to-find leak.
The team inspected the pipeline on December 29, overcoming logistical challenges of the holiday season and mobilizing within days of the initial call.
Xylem used the free-swimming SmartBall® inspection platform to listen for leaks. The tool rolls with the flow of water inside the pipeline, collecting critical data without disrupting service. Its advanced acoustic sensor, combined with its proximity to the leak, makes SmartBall far more sensitive than external leak detection methods.
The team inserted SmartBall into the pipeline using a fire hydrant upstream of the casing. Downstream, the City of Mesa installed a six-inch tap with a gate valve to enable the tool’s extraction and create an access point for future inspections.
Xylem also accelerated its reporting timeline. Within 24 hours, the onsite technician analyzed the data and confirmed the presence of a large leak. Within 10 days, Xylem delivered a detailed dig sheet pinpointing the leak’s location and providing the City of Mesa with the information needed to act decisively and proceed with confidence.
After removing the casing, the leak was visible on the 16-inch ductile iron water main.
Results
Despite the acoustic challenges posed by the thick steel casing, SmartBall successfully detected the leak within less than a foot of its actual location.
SmartBall’s precision enabled the contractor to excavate exactly where needed and quickly repair the main. This prevented costly exploratory digging along the 900-foot casing and prolonged construction delays.
The City of Mesa was able to inspect and repair the pipe for less than half the projected costs of alternative lining and sliplining options. Additionally, the repair restored the integrity of the pipe without a loss in flow capacity.
Detecting the leak during construction also prevented potential future issues, such as sinkholes, structural damage to the SR 24 overpass, and expensive emergency repairs to a newly paved roadway. In addition to protecting the integrity of the state’s transportation infrastructure, the City of Mesa’s timely repair safeguarded a critical pipeline and reduced water loss in the arid Sonoran Desert.
Ultimately, the success of this project highlights the value of preparedness, trusted partnerships, and advanced inspection technology in resolving complex infrastructure challenges.
From a broader perspective, this project underscores the importance of proactively assessing high-risk pipelines, such as those at freeway crossings. Leaks and breaks in these locations can lead to disproportionately severe consequences. The City of Mesa’s condition assessment program includes a plan to inspect all freeway crossings in its transmission network. As communities worldwide tackle the challenges of managing aging pipelines, the City’s approach demonstrates how strategic, long-term programs can empower utilities to reduce risk and address unexpected challenges.