Flood warning sparks call to clear city drains

The drainage system in Dublin must be cleared immediately to avoid floods as the highest tides in two decades approach, a senator warned today.

Cyprian Brady called on Dublin City Council to ensure all precautionary measures are undertaken to avoid floods during the expected high tides on September 10 next.

“While there has been major investment in our flood defences in recent years, many drains are blocked and this will heighten the flood risk when some of the highest tides in two decades are expected in the city in less than two weeks,” Mr Brady said.

“The Dublin Metropolitan Emergency Planning Group is keeping the situation under review, however, in the short space of time we have left it is important that the drainage system of the city is checked. Such an examination should take place before winter arrives whether there is a flood alert or not.”

The Fianna Fáil senator said it was important residents were kept fully informed of the risks of flooding ahead of the period of high tides.

He said: “It is feared the flooding will occur if the high tides coincide with heavy rain.”

Mr Brady said sandbags should be made available in the flood prone areas, especially along the Liffey River, the Dodder and Tolka, if there is bad weather forecast during the period.

“While the power of nature is impossible to control if we make the proper preparations now then we can reduce the risk to homes in the coming days,” he said.

The Irish Marine Institute warned Ireland will experience unusually high tidal ranges which will reach a peak in Dublin around September 10 and October 9 next.

In Dublin on September 10, a high tide level of 4.5 metres or 14.6 feet is predicted around 12.30am.

The institute said any flooding problems that occur will be due to bad weather, or a storm surge, coinciding with the high tides.

Twice a year, at the Spring and Autumn equinoxes the biggest spring tides occur due to the alignment of the earth with the sun.

But tides also follow an 18.6 year "nodal cycle" relating to the tilt of the moon and its orbit around the earth. This allows for an extremely big spring tide during this cycle.

When both of these occur at the same time it can result in particularly high waters, and especially low and high tides can be expected at all locations around the coast during this period.

The institute is working with a number of partners to install a permanent network of tide gauges with monitoring stations in Killybegs, Dublin Port, Rosslare, Castletownbere, Galway Harbour and the Kish Bank Lighthouse.

The information gathered can be used to increase the level of accuracy of tidal prediction and in conjunction with information from Met Eireann it can be used to predict storm surges that might cause flooding.