Friends of the Irish Environment say it's likely that it will be seeking a High Court injunction later this week to stop work to install an overflow pipe at Lough Funshinagh in south Roscommon.
The lobby group is requesting Roscommon County Council provide it with the specific legislation and the Managers Order under which it can challenge the legality of the project without the necessary assessments under the EIA, Habitats and Water Framework Directive.
Spokesperson for FIE Tony Lowes says that however traumatic it is to see houses and farmlands flood - the solution is not to try and hold back nature but to adapt to the changes.
He says a national law passed 70 years ago does not supersede European environmental regulations: