Cork North Central Solidarity TD Mick Barry has now backed calls for a tidal barrier to future-proof the city from rising sea levels caused by global warming.

“I believe that the OPW proposals are crude and do not sufficiently take into account the relationship of the people of the city with the river,” he said.

“If implemented, I would be concerned that rising sea levels in future would result in an ‘easy fix’ by building the walls higher again.”

He called for the OPW to give more consideration to alternative proposals put forward by the Save Cork City (SCC) campaign group which has criticised the OPW reliance on raised quay walls.

SCC has called for the construction of a tidal barrier at Little Island to reduce tidal flood risk, and for a raft of upstream mitigation measures to minimise fluvial flood risk.

SCC has costed its barrier at €135m but the OPW insisted this week that the campaign group’s figure doesn’t take into account site investigation works and complex engineering issues. The OPW says it stands over its tidal barrier estimates of between €500m and €1bn.

But Mr Barry said: “I am concerned that the OPW cost estimates are being used as a club with which to beat down dissent on this issue. I would like to see a genuinely independent assessment as to the cost of constructing such a barrier.”

He said he was impressed by arguments from climate change expert, Professor Robert Devoy, who has suggested that a tidal barrier will need to be constructed sooner rather than later given rising sea levels.

And he said Professor Philip O’Kane’s argument that strengthening the Inniscarra dam combined with a tidal barrier and ‘slow the flow’ initiatives upstream could guarantee against flooding of the city, should also be considered.

SCC has criticised the OPW’s dismissal of its tidal barrier estimate. The barrier proposal is contained in its submission to the OPW.