A herd of cows in Ballycullane outside New Ross in Co Wexford went without water last Sunday and Monday and subsequently couldn't be milked due to a water supply issue late on Saturday.
"Our water was turned off here at 10.30pm Saturday night," dairy farmer Anna Kehoe told the Irish Farmers Journal.
"We had no water on two of the hottest days of the year, Sunday and Monday were 30°C. I'll never forget it, it was hair-raising stuff seeing the animals like that," she said.
The dairy farmer believes that Irish Water turned off the water supply on Saturday night for maintenance work.
She said that Irish Water was "totally unaccountable" for turning off the water supply and gave no reasonable explanations as to why it happened.
"They knew perfectly well it was going to happen because they brought tankers into towns full of water before the supply was turned off," she said.
The Kehoes didn't milk their cows on Sunday evening or Monday evening in fear they would become even more dehydrated adding that she was extremely concerned as the cows were freshly in-calf.
The cows were milked Sunday morning for a bit of "relief", according to Kehoe. However, she is very concerned about their cell count going through the roof as they couldn't wash the parlour.
"One farmer came to me on Sunday and I was genuinely worried for him. He had 80 cows and 80 cattle and not a drop of water," she said.
Irish Water have a duty of care for both people and animals and it should never happen again, she said.
She also said she would be looking to speak with a representative from Irish Water over what happened.