Ottawa blasts its river ice. What would it take to do the same in the N.W.T.? | 24CA News

In 1951, a person in Hay River, N.W.T., drowned after the city skilled devastating flooding.

The explanation for the flooding was the identical factor that brought on the 2022 floods: ice jams. But a 1988 report by the federal authorities particulars {that a} flood prevention measure that had been used the earlier three years wasn’t utilized in 1951. This was the apply of ice blasting, utilizing explosives to explode river ice and stop jamming. 

“Because of the flooding in 1951, an extensive blasting program was undertaken in the spring of 1952,” the report stated.

The first point out of blasting within the report is within the Forties, however it’s unclear when precisely it was discontinued — it is not at the moment utilized by the N.W.T.

However, it remains to be utilized in a number of different jurisdictions, together with Ottawa.

Blasting on the Rideau River

Bryden Denyes is the realm supervisor for roads providers with town of Ottawa. 

He’s been answerable for Ottawa’s blasting program for eight years. This takes place within the spring and is finished to guard 900 houses alongside the Rideau River — as compared, the N.W.T. has 9 communities vulnerable to flooding, together with the territory’s second-largest, Hay River. 

Denyes stated they find areas the place ice might doubtlessly jam, typically close to bridges.

“So a shallow area with, say, a natural pinch point where the shoreline narrows is an area we definitely watch because you can have, potentially, some ice jams there depending on the thickness of the ice and how fast the flow is,” he stated. 

Denyes stated in all of the years he is run this system, there’s by no means been flooding from ice jams, just a few resulting from sheer quantity of water. 

The process may be harmful, involving explosives and ice, however Denyes stated the workers monitor the ice and make sure the blasting is finished proactively and never in a way that would injury infrastructure. 

“Our staff are trained specifically how to deal with these explosives,” Denyes stated. 

In phrases of environmental influence, Denyes stated town works with conservation companions to make sure it is not detrimental to ecosystems. He added town is additionally attempting to make use of much less explosives and extra mechanical instruments to interrupt up the ice, together with an amphibious excavator.

24CA News reached out to the federal Fisheries Department on the dangers of blasting within the N.W.T., however did not obtain a response. 

Unpredictability

The Rideau River is considerably smaller than most of the rivers that current flood dangers to the N.W.T., however Denyes stated he believes blasting can be utilized on any dimension of river — it is a matter of getting the best instruments and coaching to finish it. 

“You have to really have that knowledge of what that river system is, the infrastructure you’re dealing with, and really you’re looking at your flows, how thick your ice is,” he stated. 

Jay Boast, a spokesperson for the Department of Municipal and Community Affairs, stated in an electronic mail, “due to the unpredictability of ice and flooding in the N.W.T., flood mitigation tactics would have to be community specific and would require feasibility studies prior to initiating a measure like blasting.”

He stated at the moment the N.W.T. “is focusing on better understanding flood risk to N.W.T. communities through flood mapping efforts.”