By Alice Deyell, ’26
Once again, British Columbia is being hit with a series of atmospheric rivers, causing downpours of rain after an elongated drought. An atmospheric river is a large, narrow stream of water vapour that travels through the sky. Last year, the historic rainfall caused the flooding of 15,000 hectares of land, and 1,000 farms, and killed a multitude of livestock. The rain washed out highways and infrastructures, causing 285 million dollars worth of damage to the province.
Usually, BC is in its rainy season by mid-October, but this year there has been a fraction of the usual rain. Very warm temperatures have set records in the province for 10 out of 13 days by mid-October. According to The Canadian Press, the City of Vancouver sees an average of 165mm of rain between July and October 14th. In 2022, Vancouver received 16mm in this time period, which is less than 10% of the average amount. In the Fraser Valley, Abbotsford had 10mm, which is less than 5% of its 222mm average and Chilliwack 8mm, 3% of its 245mm average.
In many regions across BC, this drought has escalated to the most severe rating on the province’s five-point scale. Level 5 means conditions are “exceptionally dry,” and “adverse impacts to socio-economic or ecosystem values are almost certain. These regions include the Sunshine Coast, Vancouver Island, the lower mainland and some northern BC regions. Sunshine Coast governments were thinking of implementing a local state emergency due to their declining water supply. Metro Vancouver was never in such a dire predicament, though unnecessary use of water was advised against. The drought was caused by a strong high-pressure system in the North Pacific, typhoons in the West Pacific, and warmer sea surface temperatures. “Drought conditions often reinforce drought conditions,” Tyler Hamilton of the Weather Network stated. “That’s the problem, you get a feedback. Storms tracks want to avoid us.”
Finally, by the end of October and early November, the rain came. Too much rain. Now, two atmospheric rivers have hit BC and Vancouver over a few weeks, bringing strong winds along with heavy rain. Winds ranged from 40 to 60 km/h in Metro Vancouver and got up to 80 km/h in Victoria. At one point, 70mm fell in 12 hours, as reported by Environment and Climate Change Canada. Wet snow could also fall in the higher areas of Metro Vancouver such as the North Shore. As much as 30cm of snow is expected from snowfall warning for BC’sBCs interior and northern regions.
The problems that are arising because of these atmospheric rivers include power outages and disastrous flooding. There were multiple outages reported by BC hydro across Metro Vancouver in late October, with 9,000+ of their customers out of power in the Lower Mainland. Some of the wind downed an electricity line on Highway 1 in Coquitlam, causing even more loss of power. These outages will continue to happen as the atmospheric rivers pass through BC. The amount of rain hitting the dry ground might be too much after such a long drought that floods will happen. A repeat of last year would be disastrous, and the Canadian government is working to prevent such a thing.
If these atmospheric rivers keep coming to BC in the fall, more disastrous and harmful floods will most likely happen. BC’s outdated flood mitigation infrastructure struggled with the floods last year, and the federal government needs to invest in it for future years. Should we be continuously hit with droughts and floods, some areas of BC might start to expect to flood in the fall. These dry seasons followed abruptly by atmospheric rivers are causing a lot of damage to our province and are causing this fall’s abnormal weather.