Obscene images were scrawled on the statue of Our Lady and its background wall.
The hands were smashed off and horses were let in to graze in the green area surrounding the image.
Cllr Jim Long said he was appalled at what had been done to the statue.
He said: “Since it was put in place in the Marian Year, 1954, people from the entire area around Ballinacurra Weston have gone to pray there. Children were brought there on their First Holy Communion days and the statue and the surrounding area were always well kept.
“When I went to see for myself I just wondered what kind of people did this. I hope that who ever did this may some day come to realise what they have done.”
The desecration has led for calls to have it moved to another area.
Aileen Doran said: “I’m living right across the street from the grotto and its a disgrace to look at it, a disgrace. We used to come down here with the kids for their Holy Communion.
“We used to march down to the grotto and take the pictures of the children. There used to be beautiful flowers at the grotto, and it was always kept painted.”
Matt Collins, chairperson of the Ballinacurra Weston Residents Alliance said they wanted to restore the statue.
He said: “You can go to all the estates in Limerick and they all have grottos and every one of those grottos is respected. Weston is getting it bad enough and we need to stop it.”