A list of the places in Ireland where sinkholes and subsidence are most likely to occur has been revealed by Gamma, the location intelligence software and services provider. Using its risk assessment reporting tool, Perilfinder, Gamma has identified a number of areas across the country that are more exposed to subsidence events such as sinkholes.

Historic underground structures can all have an effect on risk levels

Subsidence occurs when the earth’s surface ‘sinks’ unexpectedly. It can damage or destroy buildings, land and infrastructure. Soil depth, soil type, rock type and historic underground structures can all have an effect on risk levels. The extent of subsidence, meanwhile, depends on underlying environmental factors and the design of building foundations. Using the subsidence risk model within its Perilfinder platform, Gamma found that the most vulnerable areas are in counties Galway, Clare and Roscommon. Each of these counties has more than 15% of their total buildings falling within a high risk zone. [caption id="attachment_45938" align="alignright" width="300"] Feargal O'Neill, CEO, Gamma[/caption] More than a quarter (26 per cent) of the 123,401 buildings in Galway fall within such areas. That’s more than 31,500 structures – some 26,800 of which are residential dwellings. In Clare, this percentage is just slightly lower at 24 per cent, which equates to almost 12,000 buildings, including approximately 10,200 residential buildings.

Equivalent of nearly 5,000 structures

Meanwhile, 16 per cent of the buildings in Co Roscommon fall within a high risk area which is the equivalent of nearly 5,000 structures. Again, the majority (3,800) of those are residential structures. At the other end of the scale, Wexford and Wicklow have very few buildings located in high risk subsidence areas; each less than one per cent. Across Ireland as a whole, less than five per cent of buildings (111,056 addresses) – both commercial and residential – fall within areas predisposed to subsidence events. Feargal O’Neill, CEO, Gamma, said: “Sinkholes are extreme cases of subsidence and they are rare in Ireland. However, the consequences can be devastating. "Thankfully, the recent land collapse on a GAA pitch in Co Monaghan didn’t result in any injuries; however, the sports field was damaged, the school had to be evacuated and surrounding roads were closed. Situations like this can cause significant damage and people can end up seriously hurt. “Subsidence is more common and it can affect all kinds of buildings, resulting in costly repairs. The key, therefore, is prevention. The Perilfinder tool highlights location-specific dangers such as subsidence, as well as areas that are at higher risk of flooding or crime. "This curated Irish data can be used by organisations, including insurance companies and local authorities, to assess existing threats and lower the risk.”