· Launch of Geological Survey Ireland Groundwater Flood Mapping and Hydrometric Web Service
· Karst groundwater flooding, or turlough flooding, is a feature of large areas in the midlands and west of Ireland
· Work carried out by Geological Survey Ireland has increased the understanding and data availability for groundwater flooding areas
· The new data products will inform future planning and development in flood-prone areas
The new groundwater flooding maps and data are results of the 2016-2019 GWFlood project which was established in the aftermath of the serious groundwater flooding event of winter 2015/2016. The remit of this project was to advance understanding of karst groundwater flooding in Ireland and address the deficit of data available. To achieve this, Geological Survey Ireland, in collaboration with Trinity College Dublin and the Institute of Technology Carlow, developed a monitoring, mapping and modelling programme to address the knowledge gap regarding karst groundwater systems. The project team worked with local authorities and the OPW to produce flood maps and data products which can be used to inform future flood risk management strategies.
As part of this project, European Space Agency Copernicus Programme Satellite Imagery was used to develop two types of groundwater flood maps. The first, the historic flood map, shows the extent of observed groundwater flood events, and is mainly based on satellite mapping of the 2015/2016 flood event, which in most areas represented the largest groundwater flood event on record. The second, the predictive flood maps, have also been developed for areas of recurrent groundwater flooding (turloughs), with flood levels and extents predicted for a range of annual exceedance probabilities (i.e. return periods).
Outlining the importance of the flood maps, the Minister with responsibility for Geological Survey Ireland, Eamon Ryan T.D., commented:
The affects of climate change are being increasingly seen in Ireland and we need to respond to this in scientifically-driven ways. The groundwater flooding that periodically affects large parts of the Midlands and West is a complex issue, but I am encouraged that the work of our Geological Survey is helping to contribute to solutions for vulnerable communities. These new maps will enable local and national authorities to make more scientifically-informed decisions regarding groundwater flood risk management in karst areas.
Koen Verbruggen, Director of Geological Survey Ireland, added:
Satellite data has transformed the way we are tackling many geohazards, including now the monitoring of groundwater flooding in Ireland. It provides a practical method to approach a complex problem and represents a step-change in tackling this issue.
The flood maps and their accompanying report, which have already been made available to the OPW, are available here: https://www.gsi.ie/en-ie/programmes-and-projects/groundwater/activities/groundwater-flooding/gwflood-project-2016-2019/Pages/default.aspx
Geological Survey Ireland has also launched its hydrometric data viewer and download service. The viewer, which provides real time hydrometric data from the Survey’s growing groundwater monitoring network can now be accessed at www.gwlevel.ie. This data will be of benefit to local and national authorities, researchers and individuals affected by groundwater flooding. It will be available to aid decision making on flood risk management, abstraction, infrastructural development and climate change adaptation.