The River Clady is a Medium to Large sized river in County Londonderry, Northern Ireland, a tributary of the Lower Bann. The River starts up the Carntogher mountain along with the Grillagh and flows eastwards towards swatragh this small stretch is also known as the Knockoneil River , Corlacky River or Upper Clady , Corlacky and Knockoneil are 2 of Slaughtneils Townlands and is where the Clady starts its course and it is only about 10 to 15 feet wide at this point after this the river widens as it passes through Swatragh and onwards to Upperlands where energy from the river is used for Clarke's mill. It flows onwards outside Culnady where it widens quite drastically round the old Dunglady Bridge around 20 to 30 feet across it then flows onwards where it joins the Grillagh river the rivers l