Sunday, January 03, 2016

River coping with extra discharge

The Liffey is so far coping well in Kilcullen at least with the increased discharge from Poulaphuca Reservoir, initiated by the ESB yesterday, writes Brian Byrne.

Though the level has risen significantly at the bridge since even last night, the only overrun is on the old weir section of the Camphill Nature Trail — which has happened a number of times since it was constructed in 2012.

Developments and sewerage system renewal on either side of the bridge over the last decade has provided higher and more robust banks, diluting the risk of the occasional flooding of riverside properties of the past.

This painting, by local artist Richard Murphy, who died in 1945, shows how easy it would have been for high Liffey waters to spill onto the square area in the past.

Further upstream, though the river is flowing fast and wide at Berney's Inch, there's as yet no sign of encroachment onto New Abbey land that has featured before.

The Mill Stream (above and below) is running at capacity now, but again there's no sign of imminent overflow onto land or at the vulnerable section of Mile Mill where there has been flooding before.

It's worth noting that while the ESB and County Council both issued possible flood warnings yesterday because of the increased discharge, the amount of water at 40 cumecs is less than a tenth of that being released at other key catchments, such as at the now infamous Parteen Weir on the Shannon.

As detailed recently, the hydro-electric infrastructure on the Liffey has substantially reduced the risk of serious flooding along the river since the first of the three dams was built in 1940.