Rideau Canal - The Birth Of Hogsback Falls
The story of a damned dam.
EPISODE NOTES
The spring flooding of the Rideau is something Ottawa would still struggle with more than a century later - in 1947, the river rose more than 2.5 meters, flooding whole neighbourhoods - with blame placed on bad water management at Hogsback Falls.
TRANSCRIPT
The Rideau canal was a massive terraforming operation. And nowhere is that more clear than here at Hogsback Falls (technically Prince of Wales falls, but nobody calls it that). It’s a place that gave birth to a brand new waterway - and nearly killed the guy in charge of the whole canal.
In 1816, it’s unrecognizable - just a winding stretch of the Rideau. But it has two big problems. These rapids, which need to be flooded so boats can pass through. And here, the river needs to be diverted entirely. This is the spot where the canal will split from the Rideau and carry boats all the way to the Ottawa river.
Both problems can be solved with one audacious 13.7 meter dam here. Actually forget audacious, for a while it seems impossible thanks to the sheer power of the spring flood. Every year, meltwater swells the river into a seemingly unstoppable torrent.
But flooding be damned, so to speak, they start work anyway, in 1827. And by the spring flood of 1829, the dam has collapsed… for the third time. February 1828 - gone. April, 1828 - gone. April, 1829 - gone. And this time it almost takes Lieutenant Colonel John By, the guy in charge of the whole canal, with it. He and fourty men are standing on the dam when it starts to collapse.
But for some reason they try again and apparently fourth time’s the charm. In 1829, the dam that does the trick is a timber crib design, filled in and braced with a 91 meter long ‘apron’ of broken stone. The dam’s been modernized but you can still find pieces of timber in the area along with a huge rock field, what’s left of that original ‘apron’.
And at long last, this dam changes everything around it. It raises the water level upstream 12.5 meters, flooding the rapids and turning the narrow stretch of the river into the 3.5km sq of Mooney’s Bay. It diverts the natural flow of the river into the Hogsback locks and the artificial canal all the way through Ottawa.
But most impressive, it gives birth to this: Hogsback Falls themselves. Because to be clear, none of this is natural. It’s a wastewater channel, it was excavated into the rock by hand to give excess water somewhere to flow. And that is a pretty emblematic reminder of just how much we alter the landscape wherever we go - and all along the length of the Rideau Canal.