A recently completed study is allowing the Columbia Shuswap Regional District to better understand flood and landslide hazards.
The regional district commissioned BGC Engineering to look at the hazards to people and property posed by flooding and landslides. Using a range of technology to analyze steep creeks and areas prone to flooding, the engineering firm produced a 258-page report.
The study was presented to the CSRD board of directors at their Feb. 18 meeting. Kris Holm, who directed the project for BGC was on hand to explain its scope and answer questions from the board.
According to Holm, the study, which builds on similar work in the Thompson watershed in 2019, took a look at 1000 flood plains and 450 alluvial fans at the bottom of steep creeks in the CSRD. Valuable assets like buildings near hazard areas were also identified in the study.
The geohazards in the study were ranked based on the level of priority for future assessments. Eleven steep creeks were considered a very high priority. The very high priority creeks included Sicamous Creek and Hummingbird Creek, both of which have been the site of destructive debris flows in the past.
Work on investigating the hazards posed by flooding and landslides is expected to continue. Holm said the next step will be creating detailed hazard maps; a grant application is in progress and if it is approved Holm said the more detailed maps will be completed in early 2022.
Electoral Area D director Rene Talbot asked Holm if logging practices in his electoral area might be having an impact on Silver Creek and the Salmon River which he said have been running higher and bursting their banks in ways he has not seen in 40 years. Holm replied that activities like logging and road-building in the upper basin can change hydrology downstream. In regards to the stream behaviour which hasn’t been seen in decades, Holm said mapping is important because alluvial fans at the bottom of steep creeks can lie dormant for many years before leading to destructive flooding.
Following questions from other directors about the complex study, board chair Kevin Flynn suggested scheduling a further workshop to discuss the study in detail.