Dr Alison Hoyle, director of risk and compliance at Southern Water, said: “We haven’t made this decision lightly and we know the Temporary Use Ban will have an impact on our customers.
“We’re working with the Environment Agency to ensure that we act responsibly to protect our environment. We’re asking everyone in Hampshire and the Isle of Wight to do their bit by supporting these measures and only use the water that they need.
“We’re experiencing one of the driest years on record for over a century and we’ve seen record temperatures.
“River flows are approximately 25 per cent lower than they should be for July, which is equivalent to losing more than 25 million bathtubs of water.
“We’re asking our customers to help protect our rivers and the habitats that live there by cutting back their water use.
“We believe a Temporary Use Ban is a responsible and vital step to reducing the amount of water being taken from the Rivers Test and Itchen.”
Most of England is experiencing “prolonged dry weather”, the stage before an official drought, the Environment Agency said earlier this week.
A hosepipe ban affecting the Isle of Man came into force today, the first since 2020.
High demand during the heatwave earlier this month, a dry winter and spring and rainfall very far below average for July have both exacerbated the water shortage.
The company said that an hour’s worth of hosepipe use is equivalent to more water than each person on average uses in a week in the region.