Improved river defences, facilities for storing floodwater, and changes to the way that Cork’s dams operate are some of the proposals to be examined as part of the city’s €100m flood relief programme.
OPW Minister Brian Hayes told a conference in Cork yesterday that a public consultation process on the flood proposals will be held at City Hall on July 17 and July 29. December has been set as the deadline for the final scheme to be unveiled.
Ken Leary of Arup Consulting Engineers said there were many “potential solutions” to Cork’s flooding problems and described the “potential to reduce peak flow” at the ESB dams at Inniscarra and Carrigadrohid as an important consideration in these plans.
He also said that “direct defences,” such as walls and embankments would be examined as well as storage on the tributary rivers that flow into the River Lee.
The splitting of the water flow between the north and south channel of the Lee will also be considered, he said, as will the pumping of floodwater and an overhaul of the flood warning system.
Meanwhile, the ESB’s hydro manager, Senan Colleran, said the Inniscarra dam was not designed for flood mitigation and underlined how it had “small water capacity” in comparison to the downstream river capacity. He said the dam had “limited ability to attenuate medium and large floods”.
John Martin of the OPW told residents that the dredging of rivers was complex and that it would not work in Cork City, as the flooding is tidal and that, no matter what is removed, the water will come in at a particular level.
Dr Martin said water attenuation, such as holding it back and storing it in reservoirs, could be explored for certain parts of the country as part of the national plan to counter flooding.
Examining other ways that the effects of floods could be mitigated, he told the Cobh Harbour and Chamber Conference that walls and embankments to stop water hitting vulnerable communities could be looked at, but warned such projects can also increase the risk of “water seepage”.
Mr Hayes said he was determined that the OPW will adhere to the timelines that it outlined for publication of the Lee flood relief works.
“If we stick to those timelines, get the engagement of the stakeholders in the city, there is no reason why we cannot be building the flood defence scheme at the tail end of next year,” he said.
“We are absolutely committed as a Government to delivering a solution for the people of Cork. This situation is intolerable. We cannot have a situation where the second largest city on the island of Ireland is brought to a standstill every six months or so because of a flooding threat. We need this issue resolved.
“In Cork it is not just about throwing money at the problem. It is a complicated problem… there are rainfall issues and tidal issues involved.”
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