Rivers

The Bend on the Blackwater

For most of its 167 km journey to the sea, the direction taken by the River Blackwater is influenced by geological structures that encourage its flow from west to east. These geological structures are linked to a great mountain folding some 300 million years ago and have produced a series of ridges and valleys that follow west-east axes. The Lee (89km) and Bandon (72 km) rivers also follow these geological ‘gutters’ for much of their course to the sea. Looking at the geology and at the physical features, it seems as if the Blackwater should continue eastwards and flow out to sea at Dungarvan Harbour. Instead, this river turns abruptly south at Cappoquin and forces its way through several ridges to reach the sea at Youghal. The Lee and Bandon make similar, if rather less abrupt, turns south. The reasons for this unusual behaviour have been extensively debated by geographers and geologists. One suggestion is that the north-south sections of the rivers of south Munster originated tens of millions of years ago when this part of Ireland had a chalk (Cretaceous) cover that has now disappeared. With many, many millions of years of erosion, hundreds, perhaps thousands, of metres of younger rock were removed, and the west-east ‘gutters’ in the older folded rocks were exposed and became major drainage channels. However, the lower sections of some of the well-established north-south rivers had sufficient energy to continue to dominate. The result is that in their lower reaches the great west-east flowing rivers divert along the long-established routes of older north-south flowing rivers. Ideas like this are of interest because they help us appreciate that some parts of the landscape may have great age. But they are also very puzzling and sometimes seem to raise more questions than they answer. Many of us may be satisfied just to gaze at that great river bend at Cappoquin and to wonder at the wooded beauty of the lower Blackwater.

Map drawn by Stephen Hannon.
The Bend on the Blackwater
Map drawn by Stephen Hannon.

The Bend on the Blackwater

For most of its 167 km journey to the sea, the direction taken by the River Blackwater is influenced by geological structures that encourage its flow from west to east. These geological structures are linked to a great mountain folding some 300 million years ago and have produced a series of ridges and valleys that follow west-east axes. The Lee (89km) and Bandon (72 km) rivers also follow these geological ‘gutters’ for much of their course to the sea. Looking at the geology and at the physical features, it seems as if the Blackwater should continue eastwards and flow out to sea at Dungarvan Harbour. Instead, this river turns abruptly south at Cappoquin and forces its way through several ridges to reach the sea at Youghal. The Lee and Bandon make similar, if rather less abrupt, turns south. The reasons for this unusual behaviour have been extensively debated by geographers and geologists. One suggestion is that the north-south sections of the rivers of south Munster originated tens of millions of years ago when this part of Ireland had a chalk (Cretaceous) cover that has now disappeared. With many, many millions of years of erosion, hundreds, perhaps thousands, of metres of younger rock were removed, and the west-east ‘gutters’ in the older folded rocks were exposed and became major drainage channels. However, the lower sections of some of the well-established north-south rivers had sufficient energy to continue to dominate. The result is that in their lower reaches the great west-east flowing rivers divert along the long-established routes of older north-south flowing rivers. Ideas like this are of interest because they help us appreciate that some parts of the landscape may have great age. But they are also very puzzling and sometimes seem to raise more questions than they answer. Many of us may be satisfied just to gaze at that great river bend at Cappoquin and to wonder at the wooded beauty of the lower Blackwater.

Map drawn by Stephen Hannon.
Enlarge image

 
The main rivers that flow through Co. Cork are the Blackwater, the Lee, the Banon and their tributaries.

The Blackwater rises near Kingwilliamstown in Kerry, and acts as the boundary between Kerry and Cork for 11 miles. Flowing across all of Co. Cork, the Blackwater also forms part of the boundary between Cork and Waterford in the east for a short distance, before flowing south to enter the sea at Youghal. It is 120 km long in total.

The Blackwater is a large, fast-flowing river and is very popular for salmon fishing from spring to autumn.

The Lee rises in the Shehy Mountains that lie on the border between Cork and Kerry. At certain points along its 56 mile course towards the sea, the Lee widens to form both Inchigeela Lake and Lough Mahon. It enters the sea at Cork Harbour.


As with the River Lee, the Bandon also rises in the Shehy Mountains. It is another popular fishing river, where salmon and trout are plentiful. It flows through Dunmanway and Bandon before draining into Kinsale Harbour.

These three main rivers all flow from west to east, making sharp turns to flow south into the sea. The Blackwater and the Lee act as natural drainage for most of Co. Cork.


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