Why a summer of drought could lead to fall flooding in B.C.
After a summer marked by prolonged drought and record-breaking wildfires, B.C.'s landscape has been left more vulnerable to floods and landslides, according to an expert.
UBC Prof. John Richardson told CTV Morning Live that while rainy weather brings some relief, it also brings risk – particularly if the precipitation is sudden and heavy.
"We're still talking about these atmospheric rivers, which nobody talked about five years ago. And that means that we have these really focused streams of moisture that are coming at us," he explained.
Both drought and wildfires, Richardson says, change the soil and make it less absorbent which means waters flow directly into rivers and streams. This summer's drought, he also notes, is the second year in a row the province has seen persistently parched conditions.
"Anytime we have big, big rains, we have to be concerned about those sorts of things, but the things that have happened in the last couple of years are going to lead to the landscape being a little bit more vulnerable to that rainfall," he said.
The other thing that the drought has done to rivers and streams is to clog them with twigs, branches and other debris. And brittle, drought-stricken trees are likely to lose more branches in windy conditions.
"The streams not only will have water rushing through them, but there's a lot more stuff out there in terms of twigs and things that get washed out. And as they move down, they can dislodge logs and rocks and eventually we could end up with small debris avalanches," Richardson said.
Wildfires also destabilize the roots of trees and burn surface vegetation, he said.
"The soil is no longer protected by the roots of the trees that hold the soils together. And especially in steep landscapes, that combination can lead to more landslides," he added.
Richardson also said he doesn’t think there is a risk of a repeat of the catastrophic flooding that devastated parts of the province in 2021 and he does not predict that "the whole province is going to slide into our streams but we're going to have more landslides."
However, he also said that the places most vulnerable to flooding and landslides are the ones that have already been hardest-hit by wildfires and drought.
In the last update from provincial officials on drought conditions, 80 per cent of the province's watersheds were at drought level four or five. This means that "adverse impacts on both communities and ecosystems" are likely or almost certain, according to the province's ranking system.
The wildfire season has seen an unprecedented number of hectares scorched, tens of thousands evacuated and hundreds of properties lost. It has also been a devastating one for firefighters, who have seen six of their colleagues die.
CTVNews.ca Top Stories

Poilievre calling on 'unelected' Senate to 'immediately' pass farm fuels carbon tax bill
Conservative Leader Pierre Poilievre is pushing for MPs to call on senators to 'immediately' pass a bill that would exempt certain farm fuels from the carbon price.
Chicago Blackhawks to terminate Corey Perry's contract after finding 'unacceptable' conduct
The Chicago Blackhawks said Corey Perry engaged in unacceptable conduct and took a step Tuesday toward terminating his contract, the latest twist involving the veteran winger who was mysteriously scratched and sent home last week without explanation.
Short-term rental tax changes left out of Freeland's bill to implement fiscal update measures, here's why
Finance Minister Chrystia Freeland will be tabling an omnibus bill to pass measures she promised in last week's fall economic statement. Missing from the package are the government's promised plans to crack down on short-term rentals, while the Liberal promise to double the carbon tax rural rebate top-up, is included.
Frank the Tank, a tortoise found wandering a B.C. field, gets a new home
Adoption requests came from as far away as New Zealand, but Frank the Tank, a 17-kilogram tortoise found wandering in a Richmond bok choy field last month, will be staying in British Columbia.
French police arrest yoga guru accused of exploiting female followers
French authorities arrested the leader of a multinational tantric yoga organization Tuesday on suspicion of indoctrinating female followers for sexual exploitation.
OPINION Advice on dealing with 'quiet hiring' in the workplace
In a column for CTVNews.ca, personal finance writer Christopher Liew tackles 'quiet hiring' -- a term referring to companies that quietly hire from their own talent pool rather than look elsewhere -- and outlines some tips for employees on how to take advantage of the practice.
Customer sues Chopt eatery chain over salad that she says contained a piece of manager's finger
A customer has filed a lawsuit against the fast casual chain Chopt over a salad that she says contained a piece of the manager's finger.
Alex Murdaugh sentenced to 27 years for financial fraud after victims angrily confront him in court By Jeffrey Collins
For years, South Carolina attorney Alex Murdaugh looked his anguished clients in the eyes and promised to help them with their medical bills, their suffering or simply to survive. Then he stole most, if not all, of what he won for many of them.
High-fat flight is first jetliner to make fossil-fuel-free transatlantic crossing from London to NY
The first commercial airliner to cross the Atlantic on a purely high-fat, low-emissions fuel flew Tuesday from London to New York in a step toward achieving what supporters called 'jet zero.'