Dublin city council has been told to reassess plans to rezone industrial estates for housing in flood risk areas.
The Office of the Planning Regulator says further consideration is needed.
The city council has proposed rezoning a number of brownfield sites to allow them to be redeveloped for housing.
However the Office of the Planning Regulator says proposals for land in Kilmainham and East Wall Road need further review, according to the Herald.
It says they should not be rezoned if the change isn't compatible with existing guidelines on development in flood risk areas.
The local authority earlier this month identified eight proposed sites as being at risk of flooding.
The planning watchdog says two plots in central Kilmainham, adjoining the banks of a river, are considered highly vulnerable.
The OPR raised concerns the council had not fully addressed the flooding risk and hadn't shown developing the land would not cause adverse impacts elsewhere.
The regulator has recommended that the council engage with the OPW on the appropriateness of pushing ahead with the proposal, given the flood risk.
