The ESB has said levels in Lough Derg are finally going down after weeks of swelling.
The drop means it is able to reduce the flow of water through the Parteen Weir.
The rate will be cut to 335 cubic metres per second today - down from its peak of almost 500 over Christmas.
However the change does not remove the risk of flooding for areas downstream including Springfield, Montpelier, Castleconnell, Mountshannon (Annacotty) and the University of Limerick.
An ESB spokesperson has said he is hopeful that the reduced levels will continue in the coming days.