The River Shannon is the longest river in the British Isles at 360.5 km (360.5 mi) It drains the River Shannon catchment, which covers 16,865 km2 , a fifth of the island’s area.
Shannon separates the west of Ireland (mainly the province of Connacht) from the east and south (Leinster and most of Munster). Main exception is County Clare, which lies to the west of Shannon but is part of the province of Munster. The river forms the main physical barrier between east and west, with less than thirty-five crossings between Limerick city in the south and the village of Dowra in the north.
The river takes its name from the Celtic goddess Sionna.
Shannon has been known as an important waterway since antiquity and first appeared on the maps of the Greco-Egyptian geographer Ptolemy. (c. 100 – c. 170 AD). The river flows mostly southwards from the Shannon Pot in County Cavan, then turns west and empties into the Atlantic Ocean at the 102.1 km long Shannon Estuary. The city of Limerick stands at the point where the river’s water meets the estuary’s sea water. East of Limerick, the Shannon is tidal to the base of the Ardnacrusha Dam.
Channels
The River is also connected to many canals. The Royal Canal and the Grand Canal connect the Shannon with Dublin and the Irish Sea. Shannon-Erne Waterway connects it to the River Erne and Lough Erne. Ballinasloe is connected to Shannon by the River Suck and the canal, while Boyle is connected by the Boyle Canal, the River Boyle and Lough Key. There is also the Ardnacrusha Canal connected to the Ardnacrusha Dam south of Lough Derg. Near Limerick, the short Plassey Canal connects with the River Abbey, allowing boats to bypass the Curraghower Falls. Which are a major barrier to navigation. The village of Lecarrow in County Roscommon is connected to Lough Ree by the Lecarrow Canal. The Jamestown Canal and Albert Lock form a link between the River Shannon south of Jamestown and Lough Nanoge south of Drumsna.
Fishing
Although now depleted, fishing in the Shannon Estuary once provided employment for hundreds of people along the length of the river. In Limerick, fishermen from Clancy’s Strand used the River Gandelow to catch salmon. Abbey fishermen used a net and boat known as the Breacaun to fish between Limerick City and Plassey until 1929. The construction of the Ardnacrusha Dam in 1929 seriously affected salmon farming. Which, together with the introduction of quotas, led to the closure of the salmon fishery in the 1950s. However, recreational fishing still continues. Further up the Shannon estuary at Kilrush, the Currach was used for herring fishing and also for salmon drift netting.
