Update 6.15pm: Irish Water says 16,000 are without water in counties Tipperary, Galway, Wexford and Leitrim.
Water restrictions are in place for 35,000 in Leitrim, Meath, Galway, Mayo and Cork.
Almost 12,000 are on boil water notices mainly in Enniscorthy, Co. Wexford.
12,000 households supplied by the Fethard Public Water Supply in Co. Tipperary are on a "Do Not Drink" notice.
The reduced pressure in parts of the greater Dublin area will continue tonight from 8pm until 6am.
Earlier: Irish Water is warning today that restrictions on supply could last for weeks.
Around 40,000 people are having night-time supplies rationed around Dublin in the wake of storm Emma.
More than 20,000 people have been cut off in Galway, Leitrim, Tipperary and Wexford.
The public is being advised that the process of finding and repairing problems will "not be rapid".
Kimmage resident Ray Bailey said that the restrictions have hit his family hard.
"The water went off without any warning," he said.
"The kids had to go to school with no fresh water, they couldn't brush their teeth.
"The last time this went on for a couple of weeks, back in the Big Freeze, and i actually put in an extra storage tank after that - but as you can imagine, with six of us, it still didn't last too long.
"But again, if we had had a warning, we could have stored some water."
- Digital desk