Update 5.39pm: Cork City Council have said that the burst mains that caused water outages across Cork city has been repaired.
Engineers are working on filling in the excavation around the pipe, and they expect that the normal water service will return at around 6pm this evening.
They said that it may take two to three hours for full pressure to build up across the entire network, with households and businesses at the extremities of the network most likely to experience delays.
Some discolouration to the water supply may occur when the water supply is restored. This discolouration will clear in a short time.
People have been advised to check the clarity of the water at the kitchen tap before operating drink vending machines, washing machines, dishwashers etc.
If there are any further delays in the return of normal water supply, people can contact the Irish Water helpline on 1850 278 278 or log on to www.water.ie.
Meanwhile, as water supplies are restored to over 40,000 homes and businesses in Cork following a day of disruption the focus now turns to the cost for city centre business.
Speaking today Lawrence Owens of Cork Business Association said members have been reporting significant disruption to their businesses
"It will have a knock on effect for businesses ... and is a major interruption."
Eoin English has been canvassing business reaction throughout the day and will have a full report in tomorrow’s Irish Examiner.
Update 4.13pm: Water has now been restored to large parts of Cork City as Irish Water and Cork City Council continue to make good progress on repairing a major burst in a trunk water main close to Lee Road.
It is expected that those areas that are still without water will have their supply restored by approximately 6pm this evening.
The disruption in supply was caused by a burst in a trunk water main supplying many low lying parts of Cork city this morning.
Crews working on behalf of Irish Water have now located the burst and isolated it and are carrying out repairs to a section of the pipe.
It is expected that this work will be completed in the coming hours after which supply should begin to return to the remaining affected areas.
In the meantime, water has been restored to most of the city centre business district and surrounding areas.
Areas that are still experiencing supply interruptions include Capwell, Ballinlough and Douglas.
Irish Water has apologised to all customers for the disruption caused by this incident and thanked them for their patience as they contine to work to resolve it.
Earlier: Some businesses have reported that their water supply has been restored after a burst pipe continues to cause major disruption to the water supply in Cork city.
The reports suggest the water has been restored in Barrack St, Lancaster Quay, Western Rd and Washington St.
Back here now too ! Thanks for all the updates :-)— Liberty Grill (@libertygrill) June 21, 2017
It's back here on Lancaster Quay @paradisocork— Denis Cotter (@denis_cotter) June 21, 2017
There has been no official update on the situation from Irish Water.
Earlier: Up to 40,000 residents and businesses are without water this afternoon after a major distribution pipe burst at the Lee Water Works.
Cork city council say every effort is being made to keep minimise the interruption and engineers are currently assessing the situation.
Localised flooding has been reported around the Lee Road Waterworks, which engineers are attempting to clear.
People are advised that there may be some discolouration to their water when the supply is restored, but it will clear in a short time
Earlier: Vast swathes of Cork city are without water today after a major burst on a trunk water main.
Repairs crews working on behalf of Irish Water are on site and are working to repair the burst and restore supply as quickly as possible.
But due to the location and scale of the burst, repairs to this pipe cannot be completed without disruption to some areas of the city’s water supply.
The bursting of the pipe has also caused localised flooding around the Lee Road Waterworks and city council engineers are attempting to remove this water.
"Every effort is being made to complete repairs as early as possible but it is likely that water supply will be disrupted in many low-lying areas of the city until at least 6pm this evening," a spokesman for Irish Water said.
I am afraid we will have to shut until dinner at 5pm due a burst water main #sorree— Liberty Grill (@libertygrill) June 21, 2017
Irish Water has apologised to all customers for the disruption.
It said updates on the disruption will be provided as soon as they are available on the service and supply section of the Irish Water website, www.water.ie or by calling 1850 278 278 for information.
The following areas will be without water:
The temperature in the city is currently around 22C.
A statement from Cork City Council read: “Every effort will be made to keep the interruption to a minimum.
“Some discolouration to the water supply may occur when the water supply is restored.
“This discolouration is harmless and will clear in a short time.
“Please check the clarity of the water at the kitchen tap before operating drink vending machines, washing machines, dishwashers etc.
“Please help us by informing your neighbours who may not hear this notice.”
Reporting: Eoin English and digital desk staff