The measures came into force after midnight this morning, August 24, but it is unclear when the temporary ban will end. Customers can no longer use hosepipes for cars, gardens and windows.
An unsettled week of rising and falling temperatures is predicted by the Met Office - but the weekend itself is expected to be warm across the UK. Meanwhile, some much-needed rain is forecast over the week.
A drought has been declared in south west Wales this morning after large parts of southern England were placed into the category last week. It includes the major city of Swansea.
The latest ban introduced by Welsh Water from August 19 means some 200,000 people will not be allowed to water their plants, wash their cars or clean windows using a hose