RIVERS (Lowland)
The map of Northern Ireland shows that rivers follow one of a small number of patterns in terms of their direction or destination of flow.
Lough Neagh tributaries
These include the Upper Bann, Sixmilewater, Glenavy River, Crumlin River, Blackwater, Moyola River, Ballinderry River, River Main. Lough Neagh drains north to the Atlantic by means of the Lower River Bann.
Lough Erne tributaries
These include the upper River Erne itself, Kesh River, Ballycassidy and Ballinamallard Rivers, Sillees River, Arney River (which drains the Loughs Macnean whose tributaries include the Cladagh River running out from Marble Arch), Cladagh or Swanlinbar River, Woodford River, Colebrooke River, Hollybrook River. Lough Erne drains westwards to the Atlantic Ocean by the lower River Erne).
Lough Melvin tributaries
Shared between Co's Fermanagh and Leitrim, this lake receives water from upland streams and discharges westwards to the Atlantic Ocean by the Drowes River.
Rivers draining to Lough Foyle, the North Coast, the Antrim Coast or the Irish Sea.
The most significant are the Rivers Foyle (and its main tributaries: the Strule, Owenkillew and Glenelly Rivers), Faughan, Roe, Lower Bann (which drains Lough Neagh via Lough Beg), Bush, and all the rivers flowing down from the Antrim Hills eastwards, (mainly those of the Antrim Glens), the Inver or Larne River, the Lagan and its tributaries, and all the rivers in Co Down except the Upper Bann and its tributaries. The principal Co Down lowland rivers which drain to the Irish Sea are the Lagan, Ballynahinch, Newry and Quoile Rivers and their tributaries.
Lowland rivers tend to be slow-flowing, unlike those of the uplands, but no clear demarcation is feasible. Many species characteristic of lowland rivers are shared with canals and lowland lakes.