An investigation has been launched as thousands in southeastern England were left without water for the fourth day in a row.
About 25,000 customers in Kent and Sussex had no water or an unreliable supply at the height of the disruption, according to local reports on Tuesday.
Customers began experiencing problems on Saturday, with South East Water (SEW) blaming Storm Goretti and a power cut at one of its pumping plants.
The water company has apologized to those affected, saying it is working hard to fix the issues. Water has since been restored in some areas, but problems have continued for many households.
The scale and duration of the outage prompted a response from regulators and the government.
The Drinking Water Inspectorate confirmed it had launched an investigation into the incident. The water regulator, Ofwat, said it was considering "further action" to determine whether South East Water had met its legal obligations.
The government described the disruption as "completely unacceptable."
South East Water has said the problems stemmed from the combined impact of Storm Goretti and a power cut at its pumping plant, which affected the company's ability to maintain normal water supplies across parts of Kent and Sussex.
Engineers have been working to stabilize the system and bring customers back on supply.
The incident has added to wider scrutiny of water companies' resilience and response to extreme weather and infrastructure failures, as regulators assess whether adequate steps were taken to protect customers from prolonged outages.
