In St Boniface, above, one can see the remains of an oxbow from the Red River. Detached from the main flow, it would have become, as indicated in this 1882 map, a slough perhaps flooding each spring. Not to worry, the street grid has been drawn over it anyway, good flat land for development. Just to the west (the map has west at the top) of the oxbow one can see the old seigneurial land divisions: thin narrow lots fronting on the river.
In the google satellite view, below, the edge of the oxbow is Enfield Crescent, the eccentric in the grid. The seigneurial pattern is gone, but the road that skirted the swamp (also long gone) remains, permanently embedded in the street layout.