The Paris of the Prairies Leads the Way for Pipeline Management

The city of Saskatoon supplies water to approximately 320,000 residents within the province of Saskatchewan via 1,192 km of water main at an estimated replacement cost of over CAD$2.5 billion. The city continually evaluates these linear assets within a long-term asset management plan that has contributed to reduced water main breaks (198 in 2020 compared to a 239 10-year average) and a more targeted water main maintenance and replacement program that is having an overall positive impact on the reliability of the system and citizen satisfaction. As part of this program, the city inspected 7.8 km of large diameter (600–1,050 mm) steel water mains in 2020 to assess their in situ condition. Assessing large diameter metallic pipelines was an expansion to the city’s overall inspection program, which had primarily focused on high-risk C-301 PCCP water transmission mains. Expanding the program to include metallic water transmission mains was driven by newly developed high-resolution free swimming inspection technology that would provide the city with the data they needed to make more informed decisions on these critical assets. The 2020 water main inspection program utilized multiple technologies to measure wall thickness and ovality, assess coating, and provide leak detection, all while keeping the water mains in service. In addition, structural (FEA) and remaining useful life (RUL) analyses were conducted to assist in repair recommendations, re-inspection intervals, and overall estimated pipeline life expectancy. Inspection results identified higher risk pipe sections at a highway crossing with both wall loss and out of roundness. A unique finite element analysis (FEA) was completed on pipes in this area that accounted for all these conditions—defects, out of roundness, and above normal external loading (significant depth of cover, highway crossing).