Thousands of homes and businesses in north Dublin are set to be hit with a water shortage, with some losing their supply completely.
Dublin City Council warned essential works will be carried out on a water main on the North Circular Road near Hanlon's Corner.
Water mains will be shut off, with tankers supplying those worst affected.
A spokesman said it would be switched back on depending on when the work is complete.
"There will be disruption to water supply resulting in a reduction in service with reduced pressures and loss of supply in some areas," said a council spokesman.
The water tankers supplied will be stationed at Rathdown Road and Grangegorman from 9am to 6pm.
"All efforts will be made to minimise disruption as far as is possible. Dublin City Council apologises for the inconvenience caused," the spokesman added.
"With your cooperation and understanding we hope to keep the disruption to a minimum."
Areas most likely affected will include parts of Infirmary Road, Conyingham Road, North Circular Road, Phibsboro, Stoneybatter, Grangegorman and surrounding areas.
Officials also said there would be a stop-go traffic management system in place where the works are being carried out.