Irish Water have issued a immediate Boil Water Notice for around 10,500 residents in South Tipperary.
The decision is being taken due to elevated turbidity which has affected treatment at the Glenary Public Water Supply plant.
The area impacted include part of the town centre in Clonmel, Cashel Road, Cahir Road, and Ring Road.
It follows consultation with the HSE, Irish Water and Tipperary County Council which is aimed at protecting the health of consumers.
All consumers affected by this notice must boil their water before drinking.
A map of the affected areas, detailing the areas affected, is available on www.water.ie