FLOOD defence works in Fermoy did not contribute to the deterioration of the town’s weir and mitigation measures in the city will not damage structures, the Office of Public Works (OPW) has said.
Fermoy's weir has been in disrepair for many years with parts of it crumbling. Its structure is breached in several places, meaning fish passes have been affected, leading to negative effects on salmon spawning and migration.
Problems with the weir date back more than a decade.
Cork County Council recently signed a €344,000 contract with TJ O’Connor & Associates, consulting engineers, to carry out design work for the rehabilitation of the Fermoy weir and a new permanent fish bypass channel on the north bank of the River Blackwater.
The OPW completed flood defences in the town in 2015, prompting concerns there mitigation measures had contributed to the weir’s deterioration.
However, OPW chartered engineer Ezra Mac Manamon has said this is not the case and has moved to assure damage will not be caused to structures in Cork city due to the body’s proposed €140 million flood defence scheme for the River Lee.
“We’re very much of the view, and we have looked into site records, that what we did [in Fermoy], did not have any impact on the weir. The weir is an old historic structure and it hasn’t been maintained. It is in the ownership of the local authority and it would be a big amount of money to be spending on repairing and maintaining something like that.
"We’ve looked at it. We have considered it very carefully and we’re confident that what we did, did not contribute to the [weir’s deterioration]. The flood defences in Fermoy worked and that’s an example of our track record,” Mr Mac Manamon added.
Lower Lee Flood Relief Scheme consultant for ARUP Ken Leahy said the proposed city defence works will not drastically change how the river flows.
“The reality is that the defences as part of this scheme are on the line of existing quays to similar heights to the existing quays so we’re not generally narrowing the channel. In many cases, the defences are set back like in Fitzgerald Park and the Lee Fields so there isn’t a reduction on the cross width available.
“There is a reduction in the flow going through the cross channel as a result of this so essentially there isn’t a fundamental change in the regime of how the river passes through. In the city, the only difference is the bit at the top where it currently spills in and floods the central island won’t do so because the volume is taken out from the dams.
“Now it will rise up in the river and not in the city,” Mr Leahy added.
The OPW’s Cork city flood defence scheme is awaiting ministerial approval.