Success of OPW flood relief schemes welcomed
Minister of State for the Office of Public Works, Mr. Patrick O’Donovan TD, has welcomed the news that flood relief schemes in Cork and Tipperary have prevented a substantial amount of damage to property during the recent significant weather event in southern counties.
The severity of the weather event this week has in some areas been described as more significant than that which caused the flooding in 2009 and 2015, with close to 100mm, or 4 inches of rain falling in a 24-hour period at some locations, during a status orange rainfall weather warning.
The OPW flood relief schemes operated successfully in Mallow, Fermoy, Clonakilty, Skibbereen, Bandon, Douglas and Clonmel during the period of extremely heavy rainfall and subsequent increases in river water levels at these locations.
In Mallow, a flood relief scheme costing €39.5m is in place protecting some 230 properties, while in Fermoy a scheme costing €37.5m protects 264 properties. In Bandon, a €31.4m scheme protects 392 properties, while in Clonakilty, a €29.8m scheme protects 296 properties.
Tuesday saw high flow events occurr in Mallow and Fermoy, which had an estimated return period in excess of ‘one in ten’ years (on average), and were it not for the schemes being in place in those towns, it is estimated that some 140 properties, including about 50 homes, would have been flooded.
While a very small number of properties in Fermoy experienced minor flooding, the OPW is confident that these issues can be remedied successfully in the short term, to ensure protection is provided for future flood events.
While the weather events of the last two days are relatively extreme, the schemes in all of the locations mentioned above are designed to provide protection for much bigger flood events than occurred earlier this week, namely a flood with an average return period of one in one hundred years.
The events of the past few days have again shown that Cork City is at significant risk of flooding, not just from the tide, but also from the River Lee to the west of the city, in conjunction with the tributaries, the western River Bride and the Shournagh.
Over 70mm of rain was recorded on average in the Lee catchment in a 24-hour period, an amount of rainfall that could be expected to occur in the same period about once every 5 years, roughly speaking.
Collaboration which took place between the ESB, who are in control of the reservoirs and dams on the Lee, Cork City Council, and the OPW, who have prepared the Lower Lee Flood Relief Scheme with a view to protecting the city of Cork from flooding from the Lee and its tributaries, as well as from the tide, mitigated the worst impacts of the event.