These are the lake waterbody polygons delineated in accordance with Guidance Document No. 9: Implementing the Geographical Information System Elements (GIS) of the Water Framework Directive (2003) and Guidance Document No. 22: Updated Guidance on Implementing the Geographical Information System (GIS) Elements of the EU Water policy (November 2008).
https://data.gov.ie/dataset/water-framework-directive-lake-waterbodies?package_type=dataset