City of Lethbridge officials say the city’s water distribution system has built-in redundancy and is being closely assessed as aging infrastructure approaches the end of its life cycle.
During a Jan. 20 council meeting, city staff provided an update on the state of the municipality’s water system, outlining ongoing risk assessments and future capital projects aimed at maintaining reliability and reducing the risk of major failures. Director of infrastructure services Joel Sanchez said Lethbridge’s water system is unique due to the city’s geography. The water treatment plant is located in the river valley, requiring water to be pumped under pressure to reservoirs across the city.
“The way that our system is was designed is that it is interconnected so we have pipelines that can fill these reservoirs and from those reservoirs we can actually fill or supply water to other areas depending on the needs,” Sanchez said. “There might be some conditions that might not be ideal, but we have a system that for the most part has redundancy and reliability.”
Sanchez said that design allows the system to continue operating if a major transmission line fails. In most cases, remaining reservoirs can maintain water service while repairs are completed. He also acknowledged that some water transmission pipes are aging, with some more than 40 or 50 years old, while others are about 20 years old.
Sanchez said transmission mains running through the river valley are made of the same material as pipes that have failed in Calgary in recent years, including a break in December.
“The team has been working in terms of doing a comprehensive risk assessment of the whole water distribution system, considering the pipe age, the material and the break history,” Sanchez said. “We have all the information and all the critical factors in order to plan ahead and see what options do we have.”
Sanchez said the city has recently completed an underground infrastructure master plan, which provides a snapshot of water and wastewater capacity and remaining pipe life. He said the plan will guide future capital projects. Council was also told the city does not rely on a single pipe to carry the majority of its water supply. No pipeline carries more than about 35 per cent of total system capacity, which officials said reduces the risk of a catastrophic failure.
A pair of large water main breaks in Calgary in recent times have prompted improved emergency preparedness in Lethbridge, including repair kits and preliminary designs to allow crews to respond quickly if a major failure occurs. Sanchez said the system is currently performing as expected and will continue to be monitored as upgrades are planned and brought forward to council.
The first project expected to come forward involves twinning a major transmission line to address aging infrastructure and reduce risk. Additional projects under consideration include upgrades to northeast field mains, work on south and west reservoirs and improvements along Mayor Magrath Drive North and Scenic Drive. Council accepted the update for information.
