It’s already one of the largest census metropolitan areas in B.C., but the city of Abbotsford continues to grow.
Currently home to 130,000 people, some 60,000 new residents are expected to move into the sprawling Fraser Valley city in the next 20 to 30 years.
Increasing Abbotsford’s population by roughly one-half will have a major impact on the city, including its ability to provide such essential services as water and sanitary sewer operations.
To help the city with its water and sewer services planning, its engineering department uses a computerized system that enables it to model changes to the infrastructure before it actually starts to dig and lay pipe.
Called hydraulic modelling, it enables the city’s water engineers to see on their computer screens an abstract representation of what the changes will look like and what effect they will have on the complex network of pipes, pumping stations, reservoirs and treatment centres.
“We’ve been modelling our network for a total of about 20 years,” said Tyler Bowie, Abbotsford’s senior water engineer. “We installed the latest model in 2003-2004.”
Another rapidly growing city in the Fraser Valley, the District of Mission, has also been modelling its water and sanitary sewer system.
“We use the hydraulic model to find out if there are any deficiencies in the capacity of the system,” said Hirod Gill, Mission’s manager of engineering planning and design. “When changes are made to the municipality’s official community plan, which happens about every five years, then the model gets updated.”
Gill said the hydraulic model enables the city to suss out where there are liable to be problems in the water and sewer network in the future.
“And it helps us decide when to upgrade our system,” he said. “Mission is growing quickly, as more people are moving from Greater Vancouver eastward into the Fraser Valley. We need to plan ahead for the number, location and size of pipes that we’re going to need.”
Hydraulic principles are the same as they ever were, but the tools we use to analyze them are getting better and better
— Werner de Schaetzen
GeoAdvice Engineering Inc.
To help Abbotsford and Mission keep on top of their water and sewer infrastructure requirements, the cities have been working with GeoAdvice Engineering Inc., of Port Moody, B.C., their go-to hydraulic modelling experts.
“Our business is right-sizing the pipes that are connected to a municipal water and sanitary sewer system,” said Werner de Schaetzen, GeoAdvice’s president and CEO. “We size pipes, pump stations, pressure reduction valves and reservoirs for the network.”
About 70 per cent of the company’s customers are municipalities.
“At one time or another we have worked with most of the municipalities in the Lower Mainland,” said de Schaetzen.
This is how GeoAdvice’s stock-in-trade works.
Hydraulic modelling uses advanced mathematics to design an abstract model of a municipal water and sanitary sewer system in order to identify deficiencies and plan additions and upgrades as the municipality grows and its demand for water and sewer services changes.
Hydraulic modelling illustrates the effects of changing demand and climactic conditions on water distribution and wastewater collection systems.
It predicts pressures, identifies network bottlenecks and shows how different solutions would work in the real world.
“By testing different alternatives, modelling can help minimize the cost of making improvements to the water and sewer network,” de Schaetzen said.
A hydraulic model uses a variety of historical, network and field data that is wide and detailed.
For example, for GeoAdvice to model a network of pipes, it needs to collect data on the pipes’ length, internal and external diameter, roughness, connectivity, age, material and type and age of lining.
“Hydraulic principles are the same as they ever were, but the tools we use to analyze them are getting better and better,” said de Schaetzen.
Introduced in the U.S. by the Environmental Protection Agency, computer-based hydraulic modelling has been the standard since at least the 1990s.
Before that, the manual Hardy Cross method was used to estimate the flow in pipe network systems where the inputs and outputs are known, but the flow inside the network is unknown.
And before U.S. engineer Hardy Cross came up with his eponymous method, engineers were forced to use simple trial and error in order to determine a water network’s optimal configuration.