Using rebar to slow riverbank erosion poses safety hazard for rafters, Alberta biologist warns

Jim Stelfox says practice is common on Elbow, Sheep and Highwood rivers

Image | Jim Stelfox

Caption: Retired provincial fisheries biologist Jim Stelfox stands in an area where concrete rubble is piled along a section of the Elbow River west of Calgary. (Dave Gilson/CBC)

The practice of using concrete rubble and rebar to protect riverbanks from erosion poses a safety hazard for rafters, a former government biologist says.
The warning comes after problems with rebar puncturing rafts in the Bow River, sparking nine separate calls for help over the weekend, when rafts were caught up or damaged by the metal lurking just below the surface of the water in a shallow section of the river near Crowchild Trail.
At some point in the future, I suspect we'll hear another occasion of a rafter being hung up on rebar and hopefully not killed or injured. - Jim Stelfox, retired provincial fisheries biologist
The rubble is an approved method used to prevent erosion along riverbanks.
"I've seen it many times on the Elbow, the Sheep, Highwood [rivers]," says retired provincial fisheries biologist Jim Stelfox.
Other methods include quarried boulders and field stones.
Stelfox, who has spent three-and-a-half decades working along southern Alberta waterways, says he's concerned concrete rubble could pose a safety hazard, especially when blocks of it are washed away, tumbled and broken up by floods and high water.
"At some point in the future, I suspect we'll hear another occasion of a rafter being hung up on rebar and hopefully not killed or injured."
The provincial government regulates erosion control projects along rivers. Officials say while concrete rubble is allowed, they discourage its use.
As for the recent rebar problem on the Bow River, fire officials say it's still unclear what and where that rebar came from.

Image | Calgary Rafters Rebar Bow River

Caption: Rafters make their way past Calgary firefighters working to remove rebar from the Bow River that had snagged and damaged numerous rafts over the weekend. The water level on the river was temporarily lowered Tuesday to help the firefighters access the submerged debris. (Monty Kruger/CBC)