Recent weather warnings, including an orange rainfall warning for Munster yesterday, have resulted in significant flooding in West Waterford.
Ballyduff Upper village is currently impassable, as well as the regional road from Ballyduff to Fermoy and the road from Lismore to Ballyduff.
The N72 approaching Lismore from Cappoquin at Ballyrafter near the canal is also impassable.
Waterford Council says that local diversions are currently in place.
Senior Roads Engineer with the local authority Gabriel Hynes said: "We didn't get significant rainfall in County Waterford but our problem was that they got it in Cork and Kerry and the River Blackwater has a significant catchment area.
"It's a 105miles in length so you can imagine the volume of water flowing into the Blackwater and levels happened to be quite high yesterday," according to Hynes.
At present, it's hoped roads will re-open by Friday.
"I'm anticipating that those roads will be closed again tomorrow.
"Optimistically I'm hoping that the rainfall will have passed by Friday which would allow us to re-open the N72 and regional road serving Ballyduff- Fermoy, and Ballyduff-Lismore."
