The physical impacts of climate change are being felt around the world, including at our operations, where changing patterns of precipitation and spring snowmelt can create challenges for water management. In 2017, an unusually long winter at our Highland Valley Copper (HVC) operations, combined with sharp temperature increases in the late spring, resulted in heavy snowmelt flows, also known as freshet.
This unusual event resulted in widespread flooding that stressed HVC’s water management infrastructure. Ditches and sumps were overwhelmed, there was water flow in pits, and pump systems ran at capacity. The event did not, however, present a risk to HVC’s tailings storage facilities, which are designed for much larger flooding events. To manage this larger than normal volume of water, mining was temporarily paused as the site worked to rebalance water across the site. HVC’s strong response ensured that there was no material impact to the environment, and production was not impacted.
Following this event, HVC updated a number of flood management practices and systems, including the installation of additional pumping capacity and real-time flow monitoring stations. These measures have been effective; while spring runoff levels were similarly high in 2018, the new flood management practices and systems helped to minimize the impacts of snowmelt runoff in 2018 as well as in 2019.
How the 2017 Flooding Occurred
The spring of 2017 at HVC was uncharacteristically cool, with mean temperatures generally below zero. By the beginning of May, the snowpack in the rolling mountains surrounding HVC Operations was still quite large, with snowpack surveys indicating it contained between 3-5 times more water than an average year.
Sharp temperature increases led to snowmelt flows up to four times higher than average, causing widespread flooding over a period of approximately 72 hours, followed by localized flooding throughout the following week. Site personnel mobilized to coordinate water management efforts and minimize the impacts of this flood event.
Responding to the Event
A number of projects, systems and management practices were implemented to improve future flood management at HVC, including:
- Installing additional pumping capacity during freshet conditions at key locations
- Extending the use of real-time flow monitoring stations to improve freshet management decision-making;
- Setting up a freshet monitoring and management team to coordinate activities during freshet.
- Creating simplified process flow diagrams for all dam facilities, with clear instructions on when valves need to be opened.
These improvements were tested during the spring of 2018, which saw spring runoff levels as high as in 2017, and have been instrumental in managing peak flow levels and avoiding a repeat of the 2017 flooding.
The measures introduced at HVC are an example of how we are adapting to the risks of climate change, and incorporating increased climate variability into our planning. Each of our operations faces a different set of physical climate risks, and we work to identify and implement best practices and tools to manage these risks, take advantage of opportunities, and stay resilient in the face of climate change.
Learn more about our approach to adapting to the physical risks of climate change in the Energy and Climate Change section of our website.