Water restrictions will remain in place for homes and businesses across Dublin for at least another three days despite improving reservoir supplies, council chiefs have said.
Levels at the affected Ballymore Eustace treatment plant - one of the country's biggest - have been replenished over the weekend but are still a fifth lower than needed to meet the capital's daily demands.
Supplies at treated water reservoirs also remain "critically low".
Michael Phillips, Dublin City engineer, said local authorities are working around the clock to resolve the problem but taps will continue to run dry overnight until at least Thursday.
"We are reviewing the water supply situation on a daily basis and a decision will be taken on the current restrictions as the situation evolves," he said.
"We wish to once again urge consumers all over the Dublin region to continue to conserve water, in an effort to assist us in restoring our water supply to normal."
Environment minister Phil Hogan visited the Ballymore Eustace plant today.
Up to 1.2 million people across Greater Dublin, parts of Kildare and Wicklow are being hit nightly with water restrictions, with supplies drying up in many areas between 8pm and 7am.
Traders say they are losing hundreds of thousands of euro every day as a result of the shortages.
Although householders have complained of dirty water, council chiefs said there is no problem with the quality of treated drinking water being piped through the system.
Engineers have been forced to conserve supplies after a mysterious change in the colour and cloudiness of raw water supplies.
It is suspected the dry summer followed by periods of heavy rain over recent weeks has created an unusual balance in the water.