Skip to content

Assessing flood risks in Thompson River basin

Fraser Basin Council (FBC) has received $600,000 under the National Disaster Mitigation Program
11063373_web1_180322-NTC-ThompsonRiverBasinMap
Map shows the extent of the Thompson River watershed, which includes the basins of the North Thompson and South Thompson rivers. Wikimedia Commons graphic

The Fraser Basin Council (FBC) has received $600,000 under the National Disaster Mitigation Program to embark on an ambitious project: undertaking a watershed-wide risk assessment of flood and land/debris flows covering the entire Thompson River watershed.

It is an area that covers 5.6 million hectares and four different regional districts; is the territory of four different First Nations language groups and 26 First Nations; and is home to some 200,000 people. Representatives of the cities, municipalities, regional districts, and First Nations in the watershed will work together to identify flood hazards, potential impacts, and community and infrastructure vulnerabilities, as well as the overall flood risk profiles for the area and common risks. It’s hoped that raising awareness of all the risks in the watershed will enable mitigation planning and action to address various issues, and hopefully prevent, or reduce the magnitude of, future emergencies.

“The primary things we’re looking at are flooding, debris flow, landslides,” says Mike Simpson, senior regional manager of the FBC, “especially in light of last year’s spring floods and fires. A lot of people forgot about the flooding because of the fires.” However, he notes that fire burned between 40 and 70 per cent of the Bonaparte watershed, which could have an impact on flooding.

An initial meeting in February saw 62 people from all four orders of government at the table. “We wanted them to hear about the project, share information, and ask them about key priorities.”

The first phase, which involves risk assessment, has been fully funded. “The next funded phase would be flood plain mapping, which would be useful to get to,” says Simpson. “Across the Thompson watershed we have a patchwork of flood plain maps. Enderby and Kamloops have done work on that in the past 10 years, and Cache Creek has funds and will be doing their own work.

“But we need to look at the watershed from top to bottom and fill in the gaps. Some of the maps were done in the early 1970s and are 40 to 50 years old. They’re done at a 20-foot contour level, but with today’s technology you can get them done almost to the centimetre. And there have been a lot of developments [to the landscape] since the 1970s. Rivers change.”

This first assessment stage will prioritize key areas of highest risk. “It will look at where are the homes, properties, lives, critical infrastructure that’s at risk, look at fisheries values. At the February meeting there was a discussion about where things are built. If an area is constantly prone to the risk of flooding, how have we developed it?”

Simpson says the idea for the project came about in the summer of 2016. “We wanted to know who is already doing what, who has current funding, because we’re not trying to duplicate or replicate any work. We want to reference things that have recently been done or that are underway, and fill in gaps.”

The first phase of the Thompson Watershed Risk Assessment project is expected to be completed in March 2019. Find out more by visiting the website at http://bit.ly/2FVKn6I, which will be updated regularly.



Barbara Roden

About the Author: Barbara Roden

I joined Black Press in 2012 working the Circulation desk of the Ashcroft-Cache Creek Journal and edited the paper during the summers until February 2016.
Read more