the river begins at katchewanooka lake on the north side of the community of lakefield in the municipality of selwyn, and flows south over the lakefield (trent-severn lock 6) dams and locks. after leaving the community to the peterborough city limits, the river forms the border between selwyn and the municipality of douro–dummer. the river continues south, passing through the dams associated with four more locks, enters the city of peterborough, and passes under faryon bridge at trent university. just south of the university, the trent-severn departs via a south-bound canal to the peterborough lift lock east of the river, while the river continues south to the west. it passes over several hydroelectricity dams and generating stations, and passes into the centre of the city of peterborough, as close as to downtown, as it reaches little lake. the trent-severn waterway rejoins the river there, exiting from ashburnham lock. the river leaves little lake at scotts mills lock & dam, and heads south, passes under ontario highway 7, passes into the municipality of otonabee–south monaghan, and snakes its way without any other locks or dams to reach its mouth at rice lake, which flows via the trent river to lake ontario.