About The Site
Following serious flooding in many parts of Ireland in October and November 2002, a review of national flood policy was instigated by the Minister of State at the Department of Finance with responsibility for the Office of Public Works, Mr Tom Parlon TD. Throughout 2003, the Review Group met with agencies and groups and received submissions via a public consultation process to gather information. The focus of the review was on clarifying the roles and responsibilities of the various stakeholders and to establish effective policy for the future management of flood risk in Ireland. The Final Report of the Flood Policy Review Group was approved by Government and published in September 2004. The Report set out recommendations on policy, organisation and direction of work to provide a holistic and effective State response to the risks arising from flooding in the future. The Office of Public Works (OPW) was given responsibility as lead agency to implement these recommendations. A key recommendation of the Flood Policy was the completion of a National Flood Hazard Mapping Programme with the results to be published on the internet and all information to be made available to inform future planning and development processes. The Flood Hazard Mapping website was launched in October 2006.
Flood Hazard Mapping
Flood hazard maps are used to indicate areas of land or property that have historically been flooded or that are considered to be at risk from flooding. Maps of this kind have been widely developed and implemented throughout Europe and in countries around the world. Historic and Predictive are the two principal types of flood hazard maps. These are defined as follows:
- Historic flood mapping is the mapping of observed flood events and extents as recorded by survey, photography, video, press, memory, etc. Historic flood maps are useful for providing supplementary information to predictive maps but are dependant on the availability of information captured about historic floods, and on the quality of that information available.
- Predictive flood mapping is the mapping of flood levels and extents that are predicted to occur for a given single or range of selected frequencies (such as, a 1% or 1-in-100 year return period). Predictive flood maps are produced using a range of techniques, such as hydraulic and hydrological modelling, detailed channel and floodplain surveying. Predictive maps are therefore more complex to produce and take longer to develop.
OPW are producing predictive flood maps for the country on a catchment-by-catchment basis under phase 2 of the Flood Hazard Mapping Programme. The first results are expected to be made available on the www.floodmaps.ie website in 2008, with more parts of the country added from then until 2013.
Historic Flood Information
To develop the historic flood hazard maps for the website, the OPW commissioned ESBI Computing (www.esbic.ie) in 2004 to undertake a data collection exercise to gather as much information as possible on flooding throughout the country from any organisations that had this information. Over 50 different stakeholder organisations, including Government Departments, Local Authorities, national organisations, insurance companies and members of the public were consulted and provided a range of information about past flood events. This information included engineers' reports, letters, articles, minutes of meetings, photographs, eye-witness accounts and documents.
All the flood information gathered was catalogued, reviewed, classified and made digitally available into one collection, the National Flood Data Archive.
Flood Maps Website
Historic Flood Maps were developed to display the location of all the flood events in the Flood Data Archive and link the flood events with all the different types of report information that described them. Additional mapped information, such as the Ordnance Survey of Ireland background maps, rivers, hydrometric gauge stations, drainage districts and land benefiting from drainage schemes are included to provide contextual information.
The www.floodmaps.ie web page displays the Flood Maps and provides tools and options on the page to search for and display information about selected flood events.
The location of floods is shown with either point symbols ( or ) or, if the extent of the flood is known, area symbols ( ). All available information that describes a flood, such as photos, reports, videos, press archive are listed as links and can be displayed or downloaded.
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