Cumberland, British Columbia grew out of coal mining. For decades, this industry defined daily life, employed thousands of workers, and shipped millions of tons of coal around the world. When the mine operations closed after some 80 years, more than just an empty tunnel was left behind. The closures also created persistent economic disparities in communities.
Today, the underground networks that once supported industry could help us achieve a cleaner future. The University of Cumberland is researching how abandoned shafts and tunnels can be used as a new energy source through a partnership with the University of Victoria-led Accelerated Community Energy Transformation (ACET) initiative.
At the heart of this effort is the Cumberland District Energy Project. Researchers are studying how water trapped in old mining systems can be used to generate geothermal energy that can heat and cool buildings across town.
Mayor Vicky Brown believes the project could help reshape Cumberland’s identity. The village, already known for outdoor recreation such as mountain biking and hiking, could also become a model for clean energy innovation.
“This is a way to highlight Cumberland’s history and bring a sustainable future, clean energy ethos to Cumberland,” she says. “It’s something Old Cumberland can be proud of because we’re taking that old resource waste and transitioning to cleaner energy.”
How underground mine water can heat and cool buildings
This concept is based on a simple but powerful idea. Water deep within abandoned mines tends to be cooler than air during the summer and warmer during the winter. According to ACET project leader Zachary Gould, this stable temperature difference can be exploited using heat pumps.
These systems use groundwater to regulate indoor temperatures, providing heating in colder months and cooling in warmer months. This approach has the potential to provide energy at relatively low cost while producing very little carbon.
“(The Cumberland Regional Energy Project) is technically a very large-scale geothermal heat exchanger,” explains Emily Smekal of the Cascade Institute, which focuses on geothermal energy.
Since the tunnels extend under much of the town, the system has the potential to serve a wide area. Mapping efforts by geologists have already revealed the scale of the underground network, helping researchers estimate the amount of energy it could provide.
Initial plans focus on key areas such as a proposed urban redevelopment site with a community center, municipal buildings and affordable housing, as well as an industrial area near Comox Lake.
“We were really motivated to think about this energy system in terms of how we could reduce the cost of critical infrastructure and provide important amenities to local residents,” Gould said.
“But it’s more than just an energy system,” he added. “This is an opportunity to look at resource extraction in a new way, in a village built on mining principles. This project will be able to transform the remains of mining into an opportunity and a common asset for the region, so to speak.”
The legacy of coal mining that shaped local communities
Coal mining defined Cumberland for generations. According to historian Dawn Koopman, about 16 million tons of coal was mined from the Comox Valley starting in 1888 and ending in the late 1960s. Ships leaving Union Bay carried coal to markets as far as Japan and helped fuel world industry.
This resource powered steamships, heated homes, and supported metal production through the coking process. But it also came with significant costs for the industry. Working conditions were dangerous, many miners were injured or killed, and coal burning was contributing to climate change.
Repurposing these abandoned mines for clean energy doesn’t erase their history, Koopman said. Instead, it provides a way to use it constructively.
She points out that a coal mining project proposed near Union Bay in 2011 faced strong opposition. In contrast, current geothermal initiatives are viewed more positively.
“I think it’s good to be able to use what we already have for heating,” she says.
From geological curiosities to clean energy projects
The idea to use the mine as a geothermal resource began when local geologists discussed methane issues associated with old mine sites. Over time, those conversations expanded to exploring whether the same underground space could support other energy uses.
Cumberland geologist Cory McNeil explains that while deep geothermal drilling was not practical in the area, existing mine water provided a more accessible solution. It could help offset seasonal temperature fluctuations without requiring extreme depths.
Similar projects already exist in places like Nanaimo, British Columbia, and Spring Hill, Nova Scotia, showing that the concept can also work in former mining communities.
“This is about rethinking old resources and industrial relics,” McNeil said. “It’s very powerful to look at all of this mining and consider how we can benefit from it from a more environmental perspective.”
Transforming old infrastructure into a sustainable future
Mayor Brown put this idea into action after attending an ACET webinar for municipalities.
“They said, “They’re looking for projects in collaboration with local governments.” Then I thought, “I have a project.” ”
Two blocks of city-owned land, including the village hall, capitol building, public works facilities, and recreation center, sit directly above the mine site. Brown saw an opportunity to test whether geothermal energy could support redevelopment plans for the area.
Cumberland, a small community of about 4,800 people, doesn’t have the in-house engineering resources to fully evaluate a project like this. ACET’s expertise is essential in assessing feasibility and building the business case.
“We need their academic expertise and their ability to help with those business cases and also help with the (geothermal) exploration side of it,” Brown says.
If the first pilot is successful, the possibilities extend far beyond the first site. A network of tunnels beneath the town could support wider energy use.
Lower heating and cooling costs could make the region more attractive to businesses that rely heavily on temperature control, such as greenhouses and food processing facilities. This, in turn, could provide jobs, strengthen the tax base and improve quality of life.
“We haven’t always worked well with natural systems,” Brown says. “But I think this is a model that leverages the tools and resources that are in place to respond to the needs of the community. And I think it’s much more resilient than the way we’ve done it in the past.”
