In a report responding to concerns raised during public consultations on the planned €140m scheme for the city, the OPW and consultants Arup said the majority of proposed defence walls in the city centre would be no higher than knee height.
The prospect of replacing and heightening quay walls in and near the city centre has sparked considerable opposition. One campaign group wants a tidal barrier built instead, saying that doing so 10km downstream of the city centre would cost about €140m.
As previously reported by the Irish Examiner, however, the OPW’s assessment of the tidal barrier option has ruled it out on cost grounds. In the report published yesterday, it said any tidal barrier would have to be located further downstream.
The furthest upstream location it suggested would be at Little Island, but that would cost nearly €1bn. An alternative location at either side of Great Island in the outer harbour would be technically feasible, but the OPW estimates the cost at over €1.7bn.
Addressing the potential impacts of the proposed flood relief scheme, the OPW and Arup said over €20m is being committed to carefully restore the historic quay walls. In many cases, these walls are at risk of collapse, which happened at Grenville Place during the 2009 flood that caused an estimated €90m of damage.
The report said solid river wall heights would increase to 1.2m in some areas on the river’s north channel, but river views would be maintained in all cases.
“Views of and connection to the river will be significantly enhanced with approximately 1km of new river walkway and cycleway being created as part of the scheme,” it said.
It said areas with historic features like ornate railings, such as North Mall and Sullivan’s Quay, are being redesigned to preserve existing railings and features in-situ.
The OPW/Arup report said they considered alternative proposals, including changes to the operations of the hydroelectric dams upstream of the city on the River Lee at Inniscarra and Carrigadrohid.
“Such submissions are premised on a large number of incorrect assumptions and are based on a proposed operating regime which would jeopardise dam safety by significantly increasing the risk of overtopping,” states the report.
Minister of State Kevin ‘Boxer’ Moran said the OPW has listened to concerns, and he looks forward to the start of the first phase. Cork City Council will submit it for planning in early 2018 as part of an integrated public realm project for the Morrison’s Island area of the city centre.