A hosepipe ban has been announced for Kent and Sussex as households were without water for a fifth day on Friday.
Schools have been forced to close in the counties because of outages and the warm weather has impacted supply.
South East Water on Friday said it is introducing a hosepipe ban and bottled water stations have been set up across the counties.
The utility firm, which has 2.2 million customers in Kent, Sussex, Surrey, Hampshire and Berkshire, said the temporary restrictions will come into force from June 26.
It means customers cannot water their gardens, wash cars, boats or patios and are banned from filling paddling or swimming pools.
The utility firm said demand for drinking water had reached “record levels” as temperatures soared to almost 30C this week.
David Hinton, chief executive of South East Water, said: “This situation has developed much more rapidly than last year.
“Understandably, we’ve seen customer demand increase in line with the hotter weather, however this has impacted our ability to keep all customers in supply at all times.
“Despite asking for customers help to use water for essential uses only, regrettably we’ve now been left with no choice but to introduce this temporary use ban restriction to protect customers supplies across Kent and Sussex.
“The long-term forecast for the rest of the summer is for a dry period with little rainfall, although temperatures may reduce slightly.
“Restricting the use of hosepipes and sprinklers to make sure we have enough water for our customers’ essential use, will ensure we can serve our vulnerable customers and to protect the local environment.”
The outage has affected areas including Rotherfield, Mayfield, Tunbridge Wells, Crowborough and Wadhurst.
Leader of Wealden District Council James Partridge said he is seeking an urgent meeting with Mr Hinton.
