
Richmond Hill, Ontario Turns to CIPP for Water Main Rehab
With a water main that needed rehabilitation under a busy, arterial road with public transit services, the City of Richmond Hill, Ontario, needed a minimally invasive solution that would resolve the issue.
Traditionally, Richmond Hill has been used to utilizing traditional open-cut water main replacement methods, but because of the central location of the required maintenance, Richmond Hill sought an alternative approach that would minimize disruptions to local businesses, residents, and the surrounding environment while saving taxpayer money.
The project, centered on Carrville Road between Yonge Street and Bathurst Street, involved rehabilitating 2,500 m of 300-mm cast iron water main using cured-in-place pipe (CIPP) technology. The goal was to offer a less disruptive, more cost-effective, and environmentally friendly alternative to traditional open-cut water main replacement while finishing the project on budget and ahead of schedule.
Situated along an arterial road between residential neighborhoods, Carrville Road is a busy area with transit services and businesses like Hillcrest Mall and Bathurst Glen Plaza. Ensuring that the project caused minimal disruption to the area’s businesses, residents and infrastructure was a top priority for the city, especially since digging up the water main would have resulted in traffic interruptions and business impacts.
Challenges and Key Considerations
The City had no prior experience with CIPP technology and needed to understand the practical differences between CIPP installation and the traditional open-cut method it was accustomed to. The water main’s location, running between the passing lane and curb lane on a busy arterial road, meant that an open-cut approach would have required significant lane closures, leading to traffic disruptions and inconveniences for the local businesses and residents.
The geometry of the water main fluctuated between the passing lane and curb lane in the eastbound direction. If City of Richmond Hill officials had elected to dig the water main up, they would have had major traffic disruptions, negatively affecting multiple businesses and residents. There were also 92 individual service connections along the project, all of which required internal reinstatement after the liner was installed.
Richmond Hill officials also wanted to prioritize the environmental condition and ecological integrity of the area. By using CIPP technology, not a single tree needed to be removed during the project.
Richmond Hill Project Execution
The project kicked off in July and was completed by November 2024. In addition to the CIPP lining, the scope of work included installing a temporary bypass system to ensure uninterrupted water service, replacing 23 valve chambers, and reconnecting service lines and side-street water mains. The project also required careful traffic management to avoid disrupting the flow of vehicles and transit along Carrville Road.
Early in the project, the water main had some unexpected breaks that necessitated an expedited switch to the temporary bypass system to ensure uninterrupted service for residents. Even during Rosh Hashanah, a major religious holiday, water service was never interrupted, which was particularly important for the residents and businesses in the area.
Results and Benefits
The use of CIPP technology proved highly beneficial for Richmond Hill by allowing the city to rehabilitate the water main without the need for extensive excavation, thus avoiding major traffic disruptions and reducing the project’s overall environmental footprint. The project was completed on time and under budget, with a final cost of $5,268,863.
By avoiding the need for open-cut excavation, Richmond Hill significantly reduced the project timeline and costs while minimizing greenhouse gas emissions typically associated with heavy machinery and long-term road closures. Businesses and residents along Carrville Road were able to continue their daily activities with minimal interruption, a key consideration given the proximity of Hillcrest Mall, Bathurst Glen Plaza, and Roselawn Public School.

The City of Richmond Hill now has a valuable case study that demonstrates the effectiveness of CIPP technology in urban water main rehabilitation. The project not only delivered a solution that was less disruptive and more environmentally friendly but also established a precedent for future infrastructure projects in the region.
Kyle Paterson, CET, PMP, is project manager-infrastructure delivery for the City of Richmond Hil.