The construction of a tidal barrier to protect Cork city from floods has been ruled out again on cost grounds.
Flood defence Minister Kevin ‘Boxer’ Moran said preliminary findings from a near-complete Office of Public Works-commissioned report on the costs of a tidal barrier suggest the structure is not viable, and would cost many times the figures suggested by the Save Cork City group which is leading opposition to the State’s largest single investment in flood defences.
The Minister said an independent report released by the campaigners last week, which costed their alternative tidal barrier plan at €140m, lacked detail on cost breakdowns and did not adequately address several fundamental issues, including navigation and environmental constraints.
Save Cork City asked hydraulic and engineering experts, HR Wallingford, to provide an independent cost estimate for their tidal barrier plan, which it wants combined with a suite of upstream catchment management measures.
The report described their tidal barrier proposal as viable and said it would provide many benefits over the OPW’s approach, which includes the controversial raising of quay walls.
The report said a 950-metre sector and sluice gate tidal barrier, similar to storm surge barriers in New Orleans, could be built 10km downstream of Cork City for €140m based on 2017 figures, would protect more of the city from tidal flooding, and would avoid the disruption caused by raising quay walls.
This approach would also avoid the scenario of overtopping or failure of flood walls in the city.
But Minister Moran said the OPW and its technical advisers have studied the Wallingford report in recent days and noted that it addresses the estimated cost of the tidal barrier design proposal put forward by Save Cork City rather than a report on its own design.
“From a preliminary review of the report, the OPW notes it lacks detail on cost breakdowns and does not adequately address some fundamental issues such as navigation requirements within Cork harbour or the environmental constraints which would arise due to the proximity of Special Areas of Conservation and Special Protection Areas in the harbour and which would be difficult to overcome,” he said.
“It is also noted that the report sets out the project costs at €165m rather than the figure of €140m being quoted in the media.
“In addition, the report does not include for any measures to deal with the fluvial flooding problem which exists through the city up to Inniscarra dam, all of which would still be required even if a tidal barrage was constructed.”
The OPW has yet to publish its response to the over 1,200 submissions from the public on its Lower Lee flood relief scheme.
It will include the OPW’s new report on tidal barrier costs.
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