UBC researchers say ending clear-cut logging could reduce flood risks

As officials keep a close eye on potential flooding in parts of B.C. this weekend, University of British Columbia researchers are calling on the province to change forestry practices as a way of safeguarding against flood risk long-term.

The researchers say in communities including Merritt, Princeton and Cache Creek, logging practices may have played a role in the severity of floods.

“When we take a look at what happened upstream of these towns and the watersheds draining to these towns, you find excessive clear-cut logging that has been happening,” said Younes Alila, a hydrologist with the UBC Faculty of Forestry.

He said researchers reviewed decades of hydrology studies and found many severely and consistently underestimated the impact of forest cover on flood risk.

“If you do really destructive logging such as clear-cutting, which is the norm for B.C., it significantly increases flood risk and flood severity,’ explained Henry Pham, a UBC PhD student.

They said previous studies helped create forest management policies in B.C. that allow clear-cut logging. But researchers said the new study shows it’s time for change.

“We’re actually logging, clear-cutting like there’s no tomorrow, but that logging comes at a very, very high cost to the environment and to communities,” Alila said.

Pham explained how forests protect against severe flooding in several ways.

“The trees themselves offer so many ways of mitigating flood risks, such as reducing moisture and reducing sunlight on the snowpack and interception of precipitation even before it reaches the ground,” Pham said.

“In B.C. alone, the flood risk is escalating as we continue to lose forest cover due to ongoing large-scale logging and wildfires,” said Alila.

“If we want to mitigate the costs of disasters like the 2021 flooding in the Fraser Valley or the 2018 flooding in Grand Forks, we need to change the way we manage our forest cover. Regenerative practices such as selective logging, small patch cutting and other alternatives to clear-cutting are an important way forward,” he explained.

Alila said other countries have already banned clear-cut logging in favour of less harmful practises.

Pham also said that clear-cut logging causes more severe and much more frequent floods.

“They can negatively impact river ecosystems, degrade water quality in community watersheds and cause sedimentation issues downstream. Thousands of lives and many ecosystems further downstream of clear-cut logging stand to be affected,” he explained.

In a statement to CTV News, the Ministry of Forests said: “Throughout the province we are seeing the impacts of climate change on our forests and ecosystems, with more major rain events leading to flooding, increased insect infestations, as well as drier, hotter summers leading to drought and wildfire activity.

“That’s why B.C. scientists and forest professionals always consult significant amounts of data when determining where and when to encourage harvesting,” the statement continues.

The ministry said it welcomed the new research and that B.C. is always incorporating new silviculture methods and findings into forest practises.

“It’s why we’re committed to developing and implementing alternatives to clear-cutting practices, such as selective harvesting techniques, that better support forest resiliency, ecosystem health and climate adaptation,” the statement reads.