The hospital has now revealed the problem areas have been ‘fully cleaned and repaired’ with QA able to ‘stand down the major incident’.
No patients or staff were harmed – with them relocated to other areas of the hospital.
Patients had been asked to ‘use alternative services’ where possible and only arrive at the Cosham site’s emergency department in life-threatening cases after the major incident before 6am on January 7.
All outpatients and elective procedures, excluding dialysis, chemotherapy, radiotherapy and maternity appointments, were cancelled as a result.
Three wards were thought to have been left without water.
A spokeswoman for QA, announcing the crisis had been brought under control, said: ‘Early this morning (January 7) we declared a major incident following a significant water leak within clinical areas of the ground floor.
‘The water supply was turned off to a significant portion of our site while the cause was identified and infrastructure challenges rectified. No patients or staff were harmed and we were able to relocate patients safely to other areas of the hospital.
‘Throughout the day we have been working to test the water supply and ensure the areas affected have been fully cleaned and repaired. Due to the success of this work, we are pleased to share we have now been able to stand down the major incident.
‘If you are due to attend the hospital for an appointment or procedure from tomorrow (Saturday January 8) please attend as usual, unless you are otherwise contacted.’
Portsmouth Hospitals University NHS Trust chief executive Penny Emerit said: ‘I would like to thank our incredible teams for their hard work in keeping all patients onsite safe and restoring all infrastructure and clinical services.
‘Throughout the incident, we have worked closely with our local health and social care partners, who acted quickly to offer help and support throughout, so we would like to share our thanks with them too.
‘I would also like to thank our local communities for their patience and understanding. We know having an appointment or procedure delayed isn’t easy, but it was the right thing to do given the situation we were in.
‘Please continue attending appointments and we will keep you updated with any news or information from the trust through our website and social media.’
Firefighters were called to the hospital in the early hours of the morning following reports of the leak.
A spokesman for Hampshire Fire and Rescue said: ‘Cosham firefighters were called at 5.46am this morning to assist with a major incident at QA Hospital.
‘Crews used a pump to remove water and worked alongside onsite staff to prevent further flooding before leaving the scene at 7.45am.
‘Officers continue to liaise with partners to ascertain how HIWFRS can assist.’