Ireland’s national Catchment Flood Risk Assessment and Management (CFRAM) programme began in 2011 as a response to the EU Floods Directive. While the initial surveys were cynically seized upon by insurance companies to deny flooding risk to many customers, the overall effect of CFRAM has been to focus minds on locations at risk of flooding throughout the country.
The official CFRAM study of Shannon Town was commissioned by the OPW and found that “the whole area is below sea level and at significant risk of flooding”.
While the report acknowledges that there has been no flooding to date. It also states that there is a public fear of flooding in the town. Of primary concern is that there is a significant risk of flooding if overtopping or failure of the embankments occurs.
On the basis that Shannon is at major risk from tidal flooding, Cllr Gerry Flynn has been to the fore in lobbying for a long-term solution. At the July meeting of Shannon Municipal District, he was told by senior engineer Sean Lenihan that a final report has been prepared to future-proof Shannon’s flood defences for the next 100 years and restore confidence to local residents and business owners.
In his presentation, Mr Lenihan noted ongoing concerns about the flood risks associated with the embankment defences around Shannon.
Recent surveys have identified wave action causing further damage to these embankments that were built many years ago with the available natural materials. They are now vulnerable to wave action and water overflowing into low-lying areas.
He noted that “overtopping” is quite common at the embankment, particularly during high tides and storms, and this wave action is causing erosion of the defences.
In a worst-case scenario, Mr Lenihan said this could lead to a failure of the embankments. Surveys have found that access to parts of the defences would be difficult in an emergency situation.
Clare County Council is the lead agency along with Shannon Airport and the OPW in responding to this threat. Together they have set up a steering group and commissioned the report which has just been finalised by Malachy Walsh & Partners.
Mr Lenihan said a huge amount of information is collated in the report with the aim of reducing any risk of overflowing as well as future-proofing by strengthening the embankments against erosion.
“They have done a fantastic job until now but we want to ensure that we can have confidence in them for the next 100 years,” said Mr Lenihan.
With regard to the outcome of the report, Mr Lenihan said there are works to be done to strengthen, raise and widen certain parts of the embankments.
Critical to the outcome is that Shannon Town and the airport are hydrologically linked. Both locations were taken separately in the CFRAM report which was necessary because of EU directives on state aid.
Obviously, a tidal breach in the town could cause damage to the airport and vice versa but overall the correct position is to take an integrated approach to the entire area.
Mr Lenihan noted that the Government recently launched its flood risk management plan and Shannon Town is one of the areas noted for further assessment having secured funding of around €6 million under the 10-year plan.
However, he emphasised that this has nothing to do with the embankments but CFRAM did recommend that a separate report be done and this is now complete.
Mr Lenihan said the finished report is being submitted to the key stakeholders and a copy will be sent to the OPW and to Minister Shane Ross.
The next stage is to prepare costings for the necessary works. It has been agreed by the three interested parties to immediately appoint consultants to prepare detailed designs and tenders.
Seán Lenihan expressed his confidence that funding will be provided by the various parties. He is hopeful of going straight to the contract stage once the designs have been completed.
Commenting on the presentation, Cllr Gerry Flynn complimented the council’s recently retired senior engineer Tom Tiernan for his very positive engagement in explaining the condition of the embankments and the potential risks.
One problem, said Cllr Flynn, is that Shannon has not come under the first tranche of funding in the State’s flood-risk management plan. He pointed out that there was a time when the OPW inspected the integrity of the embankments weekly but this no longer happens.
Cllr Flynn stated that parts of the embankments no longer exist due to erosion as they were constructed haphazardly during a very different time before concerns about climate change.
Seán Lenihan described the report as “very positive” and added that the OPW is putting pressure on the insurance industry to be cognisant of any works that have been done to alleviate risk.
He said that when this work is done, people will have 100% confidence as the outcome is that “pretty much all of the embankment needs to be raised, most of it needs to be strengthened and certain parts exposed to the waves will be protected”.
“These works will have a huge overall benefit for the town and will be future-proofed for the effects of climate change,” said Mr Lenihan.
Gerry Flynn now finds himself vindicated by this report as he has pursued the issue of the embankments vigorously since the publication of the CFRAM report which caused problems for many Shannon residents who have been denied flood-risk insurance.