I'd have to assume you mean the Trent-Severn waterway. It connects lower Georgian Bay with Lake Ontario via a series of canals and lakes. There's lots of info on this system on-line.. do a lil' searching.
The only "lost" canal I'm aware of is the Clinton-Kalamazoo canal, which was intended to connect lake St Clair to Lake Michigan in the 1800's. It never extended much further than Rochester from Lake St Clair and was never more than a barge canal with a towpath. When the state ran out of money to pay the workers, the canal met it's demise and in some places was destroyed by the workers themselves. Small sections are preserved in the Rochester area near Yates Cider Mill.