Drinking Water Infrastructure Risk and Vulnerability Assessment, a study undertaken by Associated Engineering, has won a 2022 Award of Excellence in the Studies, Software and Special Services category from the Consulting Engineers of Alberta.
Vulnerability and risk assessments are “a critical stage within an overall adaptive management framework to increase resilience to climate variability and climate change,” says the report.
The Alberta Ministry of Environment and Parks, and Alberta Innovates, a provincial standalone research and innovation agency, partnered to sponsor a study of the climate change risks of what it called extreme stream flow events – floods and droughts – as they could affect municipal drinking water facilities across Alberta.
Drinking Water Infrastructure Risk and Vulnerability Assessment was undertaken for three reasons: to help municipalities understand the risks of the changing climate to their drinking water infrastructure; to identify any gaps in facility and in knowledge; and to enable the creation of plans to ensure a supply of safe drinking water.
The premise of the study is that evidence suggests climate change has been altering the type and scale of natural risks to communities in Alberta and that this pattern is likely to continue through the 21st century.
“More frequent droughts and floods and changing water levels prevent municipal water treatment facilities from operating as they were designed to do,” said Vicki Lightbown, director of the Water Innovation Program at Alberta Innovates. “Environmental changes can damage the facilities, which were not designed to handle the effects of climate change. For example, flooding can increase water turbidity and that can lead to clogged water filters.”
Because drinking water facilities in Alberta are located near river, lake and groundwater systems, and because they draw water from these systems, they are affected by climate conditions and changes to these conditions.
The facility components most vulnerable to high- and low-stream water flow are source water systems (intakes, storage ponds, and pump houses) and treatment systems (buildings, process systems, and pump stations).
Distribution systems (pipelines and tanks), on the other hand, are generally less vulnerable, because they are usually underground or not close to the water sources.
“High- and low-stream events are the main ways climate change is expected to affect Alberta drinking water facilities,” said Lightbown. “Another impact of climate change, warmer water temperatures, can lead to algae blooms. As a result, water treatment plant operators need to be flexible and able to adjust quickly to changing conditions.”
The study analyzed the water infrastructure systems of 48 municipalities across Alberta.
“The large scale of the study…is unique,” said Lightbown.
The 48 facilities make up a large portion of the regulated drinking water facilities in Alberta, based on population served. Calgary and Edmonton are excluded, however, because they have their own water infrastructure studies.
To assess the vulnerability of the 48 municipal systems, Associated Engineering sent a questionnaire to facility operators.
They were asked for details on system layouts, area topography and facility Drinking Water Safety Plans (DWSPs).
DWSPs ensure consumers receive water of good and consistent quality. They consider the source of the water, and how it is treated, stored and distributed.
A safety plan is based on an assessment of risk factors that could adversely affect water quality. It also prescribes how risk factors are to be monitored and managed.
Operators’ answers to the survey showed most of them are familiar with the potential impacts of high- and low-stream flow events.
Three of the main findings of Drinking Water Infrastructure Risk and Vulnerability Assessment:
- 45 (94 per cent) of the 48 facility owners had completed DWSPs;
- 13 (27 per cent) have flood readiness plans and seven (15 per cent) have drought readiness plans; and
- 17 (36 per cent) municipal systems were moderately to highly vulnerable to high-flow events and 14 (29 per cent) were moderately to low-flow events.
The report concludes most drinking water facilities require some significant capital upgrades to rehabilitate or upgrade existing systems on 10- to 25-year cycles, depending on population growth and changing regulations.
“It will be important for future planning and the design of these systems to
consider the future uncertainty that climate change may impose on high and low stream flows,” the report said.
To read the study in its entirety, click here.