Pádraig Hoare: 70,000 homes and businesses at flood risk

More than 70,000 homes and businesses are at risk from coastal flooding due to climate change in the next 30 years - with Munster counties firmly in the crosshairs of Mother Nature’s angry response to humankind’s dereliction of duty when it comes to harming the planet.
Pádraig Hoare: 70,000 homes and businesses at flood risk
Don O’Sullivan bringing sand bags to protect the outside of the Munster Arms Hotel during the flooding in Bandon, West Cork, the result of Storm Frank in 2015. Picture: Dan Linehan

More than 70,000 homes and businesses are at risk from coastal flooding due to climate change in the next 30 years - with Munster counties firmly in the crosshairs of Mother Nature’s angry response to humankind’s dereliction of duty when it comes to harming the planet.

A stark report from Gamma Location Intelligence, which provides map and data analysis to insurance companies and local authorities for risk assessment purposes, found that approximately 62,000 homes are at risk.

Dublin will be the most affected in terms of the number of addresses expected to be impacted by extreme coastal water levels, with some 23,435 properties - or 21,513 homes and 1,922 commercial properties - at risk, Gamma said.

Munster counties will not escape the clutches of the recurring deluge.

Clare will see 7,376 homes and 1,320 businesses at risk, while Limerick will see 4,741 homes and 685 respectively.

That represents more than 13% of homes in Clare, and almost 6% in Limerick.

Cork would see just 1% of homes and businesses affected, but that still means 2,231 homes in the firing line, with 428 commercial properties.

With 2,417 or just under 3% of Kerry homes and businesses at risk, as well as 4.5% or 2,281 Waterford buildings at risk, only Tipperary will escape the brunt of major coastal flooding, according to Gamma.

It is estimated that the cost of climate change, influenced by sea level rise, on property in Ireland will be approximately €2bn, Gamma said.

Richard Cantwell, Senior Spatial Data Scientist for Gamma Location Intelligence, said: “Global warming is already having an impact on our daily lives, but the effects of it will become more tangible and extreme in the years to come.

“With increasing global temperatures, sea levels are rising which means flooding will become more commonplace. This will have a major impact on many Irish counties, particularly along the coast, and a significant number of properties are set to be affected – unless carbon dioxide emissions are reduced which will help to delay the process.”

The findings are based on a predicted global temperature increase of 2°C which climate scientists expect to happen in the next 30 years in some scenarios, Gamma said.

This increase would cause sea levels to rise and bring about more extreme weather events, leading to higher and more frequent coastal flooding.

Gamma Location Intelligence mapped out the impact of this temperature increase utilising the Digital Terrain Model within its Perilfinder software platform. This solution assesses location risk for properties including flooding, fire, subsidence and crime.

Mr Cantwell said Munster counties should consider evaluating their plans for such catastrophes.

“The aim of the research was to quantify the levels of properties at increased risk of coastal flooding due to climate change around the Irish coastline.

“There is a cost/benefit trade-off with implementing flood defence infrastructure, however with increased frequency and severity of coastal flooding due to climate change it is possible that the benefits of this infrastructure may have been understated.

More exposed counties, including those in Munster may need to re-evaluate their plans for implementing coastal defences and target the investment where it will have the greatest benefit.” Planning laws had to be cognisant of the new dangers, he said.

“It is my view that the flood risk, be it coastal, from rivers or accumulations from excess rainfall, should be fully addressed in any planning application irrespective of the size and nature of the proposed development.

“Flood risk is a key component of Local Authority Development Plans, however there have been many cases where planning applications have not fully taken these risks into consideration.

“Given that risks are likely to increase in future there may be a requirement to ensure that planning applications explicitly reference the flood risk at the site of the development, and if a risk is present propose detailed mitigation measures.”

Regarding the cost estimates, Gamma said that the average cost of a flood related insurance claim is unclear, as it is not published directly by Insurance companies.

The AA mentioned an average cost of €27,000 for domestic flood damage in 2016, while figures released by Insurance Ireland in 2012 show average claims of €16,500 for households and €47,000 for commercial property damage as a result of the flood event in October 2011.

Applying inflation and other factors to these figures, Gamma said it assumed an average household claim of €21,450 and an average commercial claim of €80,720.

It could therefore estimate the cost of climate change influenced sea level rise on property in Ireland at approximately €2bn. This figure is the cost for properties only and does not include the cost of repairing infrastructure or motor vehicles impacted, Gamma said.

An albeit unlikely but truly devastating possibility also lies ahead for Munster counties if the Great Earthquake of 1755 in Portugal was to happen again.

The monster earthquake is now estimated to have been an 8.4 on the modern Richter Scale, which would place it among the biggest of all time. Considering previous earthquakes devastated the country in 1321 and 1531, it is not beyond the realms of possibility it could happen in our lifetime.

Tsunami waves were said to be as high as 20 metres, smashing into cities as far away as Galway, partially destroying the famed Spanish Arch that protected the city’s quays.

Aughinish in the Clare estuary actually became an island due to the 1755 event, with the connection to the mainland said to have been washed away in three-metre waves.

Recent seismic hazard studies warn that a Lisbon earthquake is much more likely than previously thought.

While an 8.5 monster is most unlikely, a 6 or a 7 could be a possibility, scientists predict.

Mr Cantwell said: “Tsunamis driven by seismic events in the Atlantic would be considered to be true 'Black Swan' events, extremely rare but also extremely damaging.

Protecting the Irish coastline against every foreseeable risk is clearly not economic, however there may be certain pieces of critical infrastructure along the coastline where a tsunami would be utterly catastrophic.

It would be a useful exercise to conduct a high level risk assessment for this infrastructure, followed by a cost/benefit analysis.”

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