Dave Cooper, an engineer specializing in river engineering from Matrix Solutions, delivered a presentation at Town council’s May 27 meeting. Cooper outlined the various flood risks that are present along the Kicking Horse River based on a study that was just completed in February.
“Overall the dyke system is fairly well armoured and in good shape,” Cooper said.
However, he did point out some potential risks. The effect that sedimentation could have on future flood levels and the high-energy nature of the Kicking Horse makes it a situation that always needs to be monitored. As was seen this past winter, some winter hazards exist as well.
“The other risk is ice jams from ice coming down into the canyon. With all of these risks we have to come up with our protection guidelines,” he said.
Among the data that Cooper shared with the meeting was information regarding the maximum flow of the river going back as early as 1912 (with a very large data gap between 1921 and 1974). The maximum flow of the river peaked at an all-time recorded high in 1916, with recent highs seen in 2012 and 2007.
The study also looked at freeboard (or clearance) levels along the river to the top of the dike. The provincial guideline is to have 0.6m or greater of freeboard based on the 200 year flood level. Some areas in Golden didn’t meet that standard, but some of those sections are only slightly lower than the 0.6m guideline, often by mere centimetres.
“The only real cases where it’s a bit more is just downstream of the Highway (95) bridge,” said Cooper. “There are some spots there where it’s about 30 or 40 centimetres lower.”
But, because of the Kicking Horse’s high velocity, Matrix has recommended a free board of one metre. Priority locations for improvement include the dykes by the campground and the section behind the College of the Rockies, which is a particular concern as a high velocity region and due to debris from the islands in that section of the river.