Northern Ireland River Basin District's (RBD)'s defined for the implementation of the Water Framework 2nd cycle. Each RBD contains all waterbodies within a specific region, both land and sea. The spatial division is based on terrestrial catchments grouped as best fit watersheds. Published in July 2016 this layer was submitted as part of Water Framework Directive reporting at the time and continues to be used to defining Northern Ireland's water bodies for management purposes. The layer replaced the 1st Cycle 2009 version and has been clipped at the Border with the Republic of Ireland. No further revisions are planned.
The European Water Framework Directive was transposed to national legislation through the Water Environment (Water Framework Directive) Regulations (Northern Ireland) 2017. The Water (Amendment) (Northern Ireland) (EU Exit) Regulations 2019 ensures that the Water Framework Directive (WFD) (as transposed) and the various supporting pieces of water legislation remain implemented in Northern Ireland as National legislation.