THE urgent need for a major flood defence plan for Cork City centre was brought into sharp focus following the devastating 2009 flood which left a €100m trail of destruction.
But what can be done to protect one of the city’s most flood-prone areas?
On one side, you have the Office of Public Work’s €140m Lower Lee flood relief scheme — the single largest investment in flood defences in the history of the State.
The OPW has proposed several measures to minimise flood risk in the city, including the controversial construction of direct defences such as raised quay walls, embankments, and tidal gates.
However, it has insisted that while direct defences are the only viable and cost-effective option, it is still open to considering changes to the look and feel of the defences in certain areas of the city centre.
In December, the OPW announced the overall design concept for public consultation.
These features a suite of measures including:
- Designation of upstream washlands to facilitate greater advance discharges from dams;
- Construction of direct defences at Inniscarra Bridge, Ballincollig, Carrigrohane, and Inchigaggan;
- Construction of direct defences, including walls, embankments, and the raising of existing quay walls, on the north and south channels of the river;
- Construction of floodgates at some footbridges and boardwalk locations;
- The installation of localised surface water pumps to deal with minor flood issues in other locations.
It also includes the development of a detailed flood forecasting system; a flood warning service; and revised operating procedures at the Inniscarra and Carrigadrohid dams, in the event of extreme flood events.
There also plans to build a large river barrier west of Cork City, close to the Kingsley Hotel, to control the flow of flood water into the south channel of the River Lee, and to divert water into the north channel, which engineers say has spare capacity.
The project will also incorporate a number of public realm components, including a paved pedestrian walkway, high-quality street furniture and an enhanced plaza at the eastern end of Morrison’s Quay.
A parapet wall and railing which “reflects and respects the historic bollards” which historically adorned the quays are also planned.
The OPW says the entire flood defence plan will minimise flood risk for about 2,000 properties — 1,227 commercial properties and 878 homes — which will be defended from a once-in-a-century flood event.
A further 1,079 properties not at immediate risk of severe flooding — 613 commercial and 466 residential — will benefit from a significant reduction of flood risk.
On the other side you have, the Save Cork City group, which has called for an alternative plan to be considered — a downstream tidal barrier and upstream catchment management measures.
The OPW has consistently ruled out these proposals, saying a tidal barrier could cost up to €1bn, and that the upstream measures would not provide adequate protection against fluvial flooding.
However, in a report commissioned by Save Cork City and released last month, HR Wallingford experts David Ramsbottom and Peter Hunter, said the alternative plan is viable and provides many benefits over the OPW’s plan. They say a 950m 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.
They said it would avoid the need to build or maintain flood defences in the city centre, avoid the disruption caused by such construction, and eliminate the visual impact of raised walls.
Save Cork City spokesman John Hegarty said the report confirms what they have been saying all along. “We want the right solution for flood relief in Cork that reflects the ambition of the city,” he said.
“The walls scheme would set a new and dangerous precedent for Cork with water pumping systems and many kilometres of walls ensuring the likelihood of a future dangerous breach in the defences leaving the city more likely to be flooded in the future.
“A tidal barrier provides faster flood relief and is environmentally the better choice for the city.
“It represents better value for money for the taxpayer. In design terms, it represents a more predictable set of circumstances so the outcome and costs are predictable too. A tidal barrier is a far safer solution for people at risk of flooding by reducing that risk.”
City Hall will publish its plans for the redevelopment of Morrisson’s Island this month.
Meanwhile, Save Cork City has backed an alternative €10,000 international architectural competition to reimagine the area.
The Morrison’s Island design initiative was organised by the Royal Institute of Architects of Ireland southern region and the Cork Architectural Association with the support of the National Sculpture Factory.
All this week, the Irish Examiner will feature some of the shortlisted designs, with the winner to be announced next Monday.
The winning entry will be chosen by a jury including Yvonne Farrell, of Grafton Architects; James Howley, a conservation architect with Howley Hayes Architects; Siobhán Ní Éanaigh of McGarry Ní Éanaigh Architects; Tim Lucas, a structural engineer with Price Myers Engineers, UK; and artist and sculptor Eilís O’Connell.
The shortlisted entries will be exhibited publicly and the winner will receive €10,000.