You have it wrong. Rochester certainly was on the canal. The canal was rerouted. There is a bridge in the middle of the city, a block from Main which used to be an aqueduct, running the canal over the river.

https://www.cityofrochester.gov/eriecanal/

Part of one of the expressways, I490, runs through downtown and still has some of the old canal locks next to it as the expressway approaches downtown.