|This article does not cite any references or sources. (December 2009)|
The river rises in Killinure townland, in the boggy ground at the northern base of Ouley Hill (186 metres), and is fed by numerous drainage ditches as it passes through the farmland to the south of the town of Carryduff. From here it passes beside Carryduff open reservoir and flows north down through a gap in the Castlereagh Hills, joining with Purdysburn, which in turn flows into the Lagan valley, joining the River Lagan at Minnowburn.
The original village of Carryduff grew up at the point where the routes south out of Belfast to Downpatrick and Newcastle, and the east-west routes from Hillsborough to the head of Strangford Lough, all met at the Carryduff River.
The Carryduff River has been covered over and encased in a pipe for some of its stretch through the town.