NEW images of a possible tidal barrier at Lough Mahon that have been commissioned by the Save Cork City group.
The group, which is opposed to the river wall defences design of the €200 million estimated Lower Lee Flood Relief Scheme (LLFRS), has long advocated for a tidal barrier to address the city’s flood problems and has released the images. It follows a social media campaign backed by Cork City Council and the Office of Public works (OPW) to promote their own scheme over recent months.
Save Cork City has said the barrier will protect up to 16,000 properties including future homes built on the docklands over the next two decades.
The LLFRS plan by the OPW and Cork City Council will cover 15km kilometres of the River Lee from west of Ballincollig to the eastern tip of the Cork City island and would protect over 900 homes and 1,200 businesses. It will be completed on a phased basis and include sections of demountable barriers.
The LLFRS scheme is close to being finalised, after engineers had redesigned elements, and will be on Finance Minister Paschal Donohoe’s desk in the first quarter of next year so he can approve them and release funding.
However, Save Cork City have said the scheme will reduce public access to the riverfront and will ultimately fail.
Cork City Council and Save Cork City have been engaged in a debate, largely carried out on social media over the last year, over their widely contrasting flood defences.
The two sides are at odds over the costs of both their projects, the measurements of quay wall heights, groundwater mitigation, the efficacy of a tidal barrier, the causes behind flooding in Cork and the effects of climate change on both mooted projects.
The OPW published new images of the LLFRS scheme in September in order to address “genuine misunderstanding” of their project and City Hall chief executive Ann Doherty recently described the scheme as “holistic, evidence-based and rational”.
She believes jobs and investment in Cork city will be jeopardised if the scheme does not go ahead.
However, J. Phillip O’Kane, emeritus professor at UCC’s school of engineering, has criticised the LLFRS plans for their potential to make Cork a “building site”, the possibility of creating a division between the northside and southside of the city and its lack of groundwater mitigation.
He has said the walls are a “waste of public money” and are not needed to protect the city from the river. He has backed the campaign for a tidal barrier.
“Walls and embankments are not needed if we build a tidal barrier,” he said.
“The ESB’s Lee dams are capable of protecting Cork from one in 100-year flooding on the River Lee and consequently flood walls sare not required to defend the city, A tidal barrier at the exit to Lough Mahon solves tidal and groundwater flooding in the city,” he said.
Despite this, OPW engineers have said a barrier flood solution for Cork is “unsafe” and would cost millions of euros per year to operate.
They have also claimed a barrier would impact shipping, tourism and commerce.
Ken Leahy, of LLFRS consultants ARUP, has dismissed claims that the OPW system, based on containment and pumping water, will fail.
Councillors at City Hall were told in the summer that an assessment of the OPW scheme, independent of the State Department and its consultants, could not be carried out. Save Cork City are calling for the independent review which councillors voted for to go ahead.