To combat ice sheets on the Ottawa River in Canada, you might say explosives are this team’s dynamite.
Ice builds up on a 9-kilometer stretch of the Ottawa River each winter, creating an icy problem should water swell behind an ice jam and flood any of the 900 buildings nearby.
A quick remedy–dynamite.
“Ice blasting” started in the 1880s according to a BBC article. By the 1960s and 1970s, the explosive practice became an annual flood prevention measure.
Since mid-February teams have used buzz saws and amphibious ice breakers to carve channels in the ice. The Manitoba Water Stewardship uses similar ice breakers on the Red River, but it does not use dynamite to break up ice flows.
Once channels are made, holes are dug and 1,543 to 3,000 pounds of dynamite is inserted over the course of a season. The ice pieces quietly float downriver after the blast. Ottawa spends $460,000 a year on the practice, but officials say flood clean ups would cost more.
Ice blasting season ends in March, though the city now uses ice breakers more often than ice blasting to protect wildlife and reduce the impact to bridges.