Residents near Lough Funshinagh in Co Roscommon say they are relieved that an interim pumping system is now operational.
Since 2016 flooding at the former turlough has led to devastation in the community with the loss of homes and land.
2.5 kilometres of piping is being used to bring excess water from the lake through Curraghboy and into a nearby river.
The pipes have been placed on the surface of the land and the pumping will be controlled to ensure that no issues arise downstream.
OPW Minister Kevin 'Boxer' Moran who officially switched on the pump today said it was a significant day for the community who had endured years of flooding.
Minister Moran said his Department is committed to finding a permanent solution and for now this will ease the worries of the local community, allowing them to sleep soundly in their beds at night knowing their homes will not be flooded.
"It's been a long time in the making but today is a very big day for the people," the minister said.
Many of the residents gathered today to watch the pump being switched on.
"It means the world to us, we've been through quite a bit" said Tom Carney, one of the affected residents.
Roscommon County Council has said that it is progressing with the design and environmental assessments to find a permanent plan.
It is anticipated that an application will be ready for submission to An Bord Pleanála towards the end of this year.
Read more:
Flood relief scheme at Lough Funshinagh gets planning go-ahead
'Shocking' experience for people around Lough Funshinagh - Tánaiste
Taoiseach meets Lough Funshinagh residents affected by flooding
