Under the Microscope/Prof William Reville: I was born and raised in New Ross, less than 100 yards from the River Barrow. The river occasionally overflowed its banks and I well remember the misery of a flooded ground floor in the house.
Flooding in Ireland is now more common and severe than in the past and the scientific predictions are that global climate change will exacerbate the situation in years to come. We have just witnessed severe and expensive flooding in many Irish towns in late October. These towns were caught without adequate flood warning, but there was one exception - Mallow. The warning system in operation in Mallow should be extended on a widespread basis.
The heavy rainfall on Wednesday, October 27th, that led to the extensive and costly flooding on October 28th and 29th in many parts of the South and East of Ireland was forecast two days in advance by Met Éireann. So why were urban centres like Clonmel, Cork, Kilkenny and Wexford, to name but a few, caught without adequate flood warning? On the other hand, Mallow on the River Blackwater was well warned and consequently well prepared.
Cork County Council, using its experience combined with the flood-warning web pages of The Flood Study Group at University College Cork (www.irishfloodwarning.com), issued a flood warning to Mallow residents on the Wednesday night at 10p.m. The Council warned that floodwater would enter Bridge Street, Mallow at about 7 a.m. Thursday and that the flood would peak at about 5 p.m. on Thursday.
The Council's timing and height predictions of the flood were accurate. The warning given about six hours in advance of the flood allowed householders, shopkeepers and the Council to mobilise emergency plans. Cork County Council is to be commended for its military precision in dealing with the warning and their emergency preparedness for flooding in the Mallow region. It goes without saying that other flood-risk towns around the country would benefit from a Mallow-type flood-warning system.
A flood-warning system neither reduces the height of a flood nor the areas flooded, but it should give sufficient warning so that people can be safely evacuated and furniture and shop goods can be moved off ground levels. Millions of euro could have been saved in the affected towns if robust flood-warning systems were in place prior to October 28th.
Much of the problem of October 28th can be attributed to the lack of a national strategy on flood warning. Responsibility for our rivers and estuaries is shared by many agencies. At least eight agencies have monitoring networks of some kind on the river Lee in Cork. These agencies include: The ESB; Cork County Council; University College Cork; The Fisheries Board; The Environmental Protection Agency; Cork Harbour Authority; Met Éireann, and the Office of Public Works (OPW). Unfortunately, there is little or no formal coordination between these agencies on flood matters. However, local authorities suffer the brunt of public criticism after a flood event. If the River Lee is representative of the national problem, lack of inter-agency coordination is at the root of our deficient strategy on flood warning.
A robust flood-warning system has three essential interconnected components: (1) accurate rain forecasts (2) instantaneous updating of expected river flood levels, and (3) an emergency procedure for protecting (e.g. road closures) and informing the public (e.g. live web pages).
Reliable rain forecasts are the responsibility of Met Éireann, which has an excellent track record. Local authorities have excellent track records on emergency planning. Updating of expected river-levels is the weak factor with no single agency responsible for providing this information.
Up to now, the weak link politically has been the lack of a national strategy for flood warning. The Minister for the Environment, who oversees local authorities, is well positioned to address this issue. An inter-departmental group from Met Éireann, OPW, local authorities, universities and the insurance industry, should be mobilised to develop a brief for a national flood-warning strategy. These five agencies are important contributors and none should be omitted from this discourse.
Most developed countries have web-based operational flood-warning systems. In many locations you simply type in your postcode and up pops the current river-level and advice as to the probability of flooding in your area. More sophisticated web systems, like the one developed for Mallow by Ger Kiely and Gearóid Corcoran of the Flood Studies Group at UCC, show continuous graphical updates of river levels.
With further development, it is possible that alongside the regular Met Éireann weather bulletins, detailed flood warnings for specific rivers could be issued. Viewers or listeners could be directed to web addresses for updates of local river flood warnings.
Politicians are likely to come under increasing public pressure to provide sustainable urban flood warning and protection measures. To date, we have been very lucky to have few fatalities during flooding. The impending climate change may see our luck running out, and that of the politicians who fail to act.
William Reville is associate professor of biochemistry and director of microscopy at University College Cork