Defences needed as floods set to become more frequent, expert says

Coincidence of low pressure, spring tides, rising seas and heavy rain becoming more frequent

High seas batter Tramore seafront in January. Prof John Sweeney of the Irish climate analysis and research unit at NUI Maynooth said the confluence of high winds, rising sea levels, low pressure and heavy rain, which has given rise to the flooding this week, is set to become more frequent.

High seas batter Tramore seafront in January. Prof John Sweeney of the Irish climate analysis and research unit at NUI Maynooth said the confluence of high winds, rising sea levels, low pressure and heavy rain, which has given rise to the flooding this week, is set to become more frequent.

Tue, Feb 4, 2014, 01:01

As coastal and riverside communities mop up after their wettest January in two decades, Met Éireann has predicted that tomorrow will be another day of severe coastal storms – with at least two more such days before the end of the week.

In addition, adverse conditions which brought flooding to homes and businesses in counties Limerick, Galway Kerry, Cork and Wexford, are set to become significantly more frequent in coming years, with a need for multimillion- euro spending on riverside dykes and coastal defences.

That is the view of weather forecasters, climatologists and planners who yesterday called for better flood-prevention measures, better planning and more enlightened climate change strategies.

Prof John Sweeney of the Irish climate analysis and research unit at NUI Maynooth said the confluence of high winds, rising sea levels, low pressure and heavy rain, which has given rise to the flooding this week, is set to become more frequent.

Prof Sweeney said there had been two moons in January with exceptionally high tides, while the low pressure would also have encouraged high seas and the extra rainfall made rivers overflow, particularly where there was a strong coastal wind along an estuary.

“With climate change ratcheting up in the background, events which have been described as one in a 100- year storms, will become more like one in 20-year storms.”

Referring particularly to floods in Limerick, where the Shannon broke its banks, Prof Sweeney said many of the earthen banks were suitable for the last century. A climate change towards warmer, wetter weather had already begun to deliver heavier, more intense rainfall and it may be appropriate to engineer higher banks in order to protect the city. He called on the Government to redouble its efforts to reduce greenhouse gas emissions which he said were rising again with the pick-up in the economy.


Shannon dyke
Former Green Party minister and DIT lecturer in town planning Ciarán Cuffe agreed that a new dyke may be necessary along the Shannon.

He said the appropriate response to the recent flooding was a mixture of engineering riverside and coastal defences and tighter planning controls. The insurance industry appeared to have the best flood plain maps and these should be shared with the Office of Public Works. Mr Cuffe said while some coastal areas could not be defended there were inflatable barriers and barriers that could rise from the ground in minutes and were suitable for protecting areas such as Clontarf in north Dublin.