North to south (more or less)
Shannon Harbour: 36th lock
Shannon Harbour: below the 36th
Shannon Harbour: road to Banagher closed
Banagher: the harbour above the bridge
Banagher: the harbour’s sole inhabitant
Banagher: work goes on
Portumna Bridge: Hawthorn moving
Below Portumna Bridge
Above Portumna Bridge
Portumna Bridge: Waterways Ireland yard
Mountshannon: the main quay
Scarriff: the river in flood
Scarriff: the river flowing on to the road to the harbour
Scarriff: sandbags blocking the road …
… to the Waterways Ireland Shannon HQ. Anyone in the building must have waded there
Killaloe: the flash lock
Killaloe bridge from downstream
Water level with the quay at O’Briensbridge
Flooded fields at O’Briensbridge
O’Briensbridge is on the original course of the Shannon, downstream of Parteen Villa Weir, which controls how much water goes via the original course and how much goes to the hydroelectric power station at Ardnacrusha.
Normally, the original course gets the first 10 cubic metres per second (10 cumec, they say) of water and Ardnacrusha gets the next 400, 100 for each of its four turbines. In floods, any excess is sent down the original course, through O’Briensbridge, Castleconnell and Plassey. One newspaper today said that, on Monday 7 December 2015, 315 cumec had been sent down the original course and, on Tuesday 8 December, 375 cumec.
The water levels are still below the peak achieved in November 2009, but there is more to come: as the Shannon drains a very large amount of Ireland, and as it is falls very little in its upper reaches, it takes a long time for the runoff to reach Killaloe and Parteen Villa. It may be that the ESB, which controls Ardnacrusha and Parteen Villa, is now running down the level of Lough Derg to make room for the water that has yet to arrive from the upper Shannon.