Those without water are include just over 300 in Cork; 800 in Williamstown in Galway; just over 1,000 in Tuosist in Kerry; 300 in south Dublin; and just over 2,300 in Waterford; and nearly 7,000 in Wexford.
Irish Water is especially appealing to anyone with an outside tap to ensure that it is securely turned off.
He said the plant, which was recently opened, will require major remediation works.
In all 11,600 people are without water and an additional 126k have restricted supply due to low levels in reservoirs.
While hospitals on the network have been prioritised and have water diverted to them.
The depleted reservoir levels around the country are partly due to households and businesses that chose to leave taps running to prevent pipes from freezing.
He said that efforts were being made to clean water as fast as possible.
"Because I think even to get back to the baseline leakage level which we had a week ago which wasn't satisfactory in this area where we only have two or three percent headroom at any one time, it means that we are under pressure now to manage pressure, to try and balance water between reservoirs so we can keep all areas of the region supplied and hopefully not have significant outages of water".
He urged households to conserve water by limiting use of washing machines and dishwashers, having shorter showers and turning the tap off when brushing teeth.