Could a Calgary-like water disaster happen in Metro Vancouver?

Metro Vancouver policy calls for continuous maintenance, including catching up with repairs to 12 per cent of its water system deemed in very poor or poor condition in a 2022 inventory.

Two years after a Metro Vancouver report rated 12 per cent of the region’s water infrastructure as either “poor” or “very poor,” some of the deficiencies have yet to be repaired. A senior manager for the regional district said this week that projects flagged for immediate attention are “at various stages, ranging from pre-design to design phases,” but the size and complexity of repair projects take time to plan and execute. “Given that the (Metro) water system is over 100 years old, leaks happen,” said Daniel Roberge, deputy general manager of operations for water resources at Metro Vancouver. “However, they occur at an annual rate of less than one leak per 100 kilometres of pipe.”

Scrutiny of water infrastructure has intensified in recent days after a water main break in Calgary cut off more than half the city’s supply. In Calgary, on June 6, a section of an 11-km-long trunk line in the city’s northwest that serves 1.2 million people failed, forcing water restrictions for a large part of the city. That’s a nightmare scenario that municipalities are constantly in a race to avoid, said Troy Vassos, an engineering consultant and adjunct professor in civil engineering at the University of B.C. “Water main breaks occur very frequently, they just don’t occur on the major trunk lines so often,” Vassos said. That means drafting plans for continuous replacement of aging infrastructure, which Canadian governments, especially at the higher levels, might not have long enough histories to fully grasp the need. Vassos said federal and provincial governments made big contributions to municipal infrastructure in the 1950s and ’60s, “but 40 to 60 years later, there has to be a plan in place for replacing it.”

Roberge said Metro Vancouver is “committed to maintaining and upgrading our infrastructure,” which is the backbone of water distribution for the region’s 21 municipalities. It consists of: three watershed reservoirs, the Capilano, Seymour and Coquitlam; five dams to control those watersheds; two water treatment plants; 520 km of large-diameter water mains; 19 pump stations to maintain pressure; eight re-chlorination stations and 26 community reservoirs for in-system storage. The 2022 State of the Assets Report rated Metro Vancouver’s overall system as in “good” condition. Its estimates were made from a mix of evidence-based inspections and projections based on expectations for the age of equipment made on a five-point scale from very good to very poor. On balance, Metro Vancouver estimated that 12 per cent of its infrastructure was in either ‘poor’ or ‘very poor’ condition, with very poor defined as at risk of imminent failure within 12 months. Within categories, the report estimated Metro Vancouver’s water mains to be in ‘fair’ condition with two per cent judged to be in ‘very poor’ and 10 per cent in ‘poor’ condition. Its 26 system reservoirs were also judged to be in fair condition with one per cent judged to be in ‘very poor’ and 25 per cent in ‘poor’ condition, 40 per cent ‘fair’, 28 per cent good and six per cent ‘very good.’ The water supply reservoirs, dams, re-chlorination stations and communications systems were judged to be in ‘good’ condition, its water treatment plants ‘very good,’ meaning in new or excellent condition. The 2022 report was part of a 2019 Metro Vancouver policy aimed at the continuous improvement of maintaining its assets. At the time, the report estimated necessary maintenance to cost $236 million per year over the long-term. Over the immediate horizon, however, Metro Vancouver had committed $248 million to repairs.

The 2024-28 financial plan for Metro Vancouver’s water district listed 80 maintenance projects, worth $889 million, among more than $3.3 billion in capital projects it wants to complete over that time, with $105 million committed for the 2024 budget year. Some 48 maintenance projects were identified as under construction, though the condition of the assets wasn’t identified. An additional 25 capital projects in the 2024-28 plan were identified, with 13 of those under construction, and 11 identified as upgrades. Vassos used the analogy of an ordinary house to describe the need for infrastructure replacement. A home’s roof, walls, driveway in front, sewer and water lines will “all fail over time.” “It all boils down to how much effort the municipality puts into the detection of these problems to get at them before they become a catastrophic break that takes a long time to fix,” Vassos said.

The characteristics of Metro Vancouver’s system, however, with the three watershed reservoirs for H2O, and backup between municipalities, give operators room to work around a lot of major problems, Vassos said. Those three “huge storage reservoirs,” Vassos said, would be able to provide the volume of water needed while a major repair is underway. Calgary, however, which draws water from two rivers, has more limited storage capacity. Roberge said Metro Vancouver also has a “flexible distribution system with a high level of redundancy,” which gives the regional district options to direct water from different sources to different parts of the region. “This allows for the uninterrupted delivery of water even while sections of the system are isolated for repairs,” said Roberge. Vassos added that Metro Vancouver and its municipal members routinely co-operate on emergency planning so that “most of the time, the public isn’t aware of any problems. They just get fixed or are dealt with.”

Source: Vancouver SUN