Ottawa uses dynamite to clear up ice in the Rideau river. It’s the first time I’ve heard about this program.
Since mid-February, specialist workers have been using buzz saws and amphibious ice breakers to cut channels and long grooves in the ice. The next step is to drill holes, pack these holes with sticks of dynamite, and blow apart the sheets of ice.
Basically, it helps prevent massive flooding in the spring time.
Update: Another article from The Globe and Mail.