The country’s largest water firm, will ban its 15 million customers in London and the Thames Valley from watering gardens or washing cars and ask them to conserve supplies.
It hopes the restrictions – which could be in place for weeks – will save up to 10 per cent of supplies and reduce the amount used per person from 150 litres to nearly 100 litres a day.
The restrictions do not apply to businesses but they are being urged to “use water wisely” and not wash vehicles.
The company said the ban applies to:
Watering your garden, allotment or plants
Filling or maintaining your paddling pool, swimming pool or hot tub
Cleaning your vehicles
Cleaning windows, walls, paths, patios and other artificial outdoor surfaces like artificial grass
Recreational use like water fights and water slides
The ban applies to hosepipes, and anything attached to them, like sprinklers and jet washers.
The ban will remain in force until there is “prolonged and significant rainfall”. People found to be breaching the rules, which can result in fines up to £1,000 for repeat offenders, will be contacted by Thames Water and asked to change their behaviour. Cases rarely result in criminal prosecutions.
Thames said it had become the latest UK water firm to impose restrictions after the driest July in 135 years and the hottest recorded temperatures since 1885 led to a drop in reservoir levels. The River Thames is at its lowest level since 2005.
It said reservoir storage levels in London and Farmoor, Oxfordshire, had “reduced significantly” and were at levels not seen for about 30 years. Groundwater levels are heading towards levels normally only seen once a decade.
But Lib-Dem environment spokesman Tim Farron said the ban was a “slap in the face” for residents when Thames was losing a quarter of all the water it supplied due to leaks.
He said: “Their gross negligence to fix leaks is set to inflict hosepipe ban misery across the South. We wouldn’t be in this mess if Thames Water bothered to invest properly. Instead, water companies are choosing to pay themselves billions of pounds in profits.”
Thames said it is drawing 120 million litres of groundwater from its North London Aquifer Recharge System to top-up the water stored in the reservoirs.
Mayor Sadiq Khan has warned that the ban could be in place for weeks unless Londoners were “good citizens” and limited their use of water.
Sarah Bentley, Thames Water chief executive, said: “Implementing a Temporary Use Ban for our customers has been a very difficult decision to make and one which we have not taken lightly.
“After months of below average rainfall and the recent extreme temperatures in July and August, water resources in our region are depleted.
“Despite investing in the largest leakage reduction programme in the UK, customer demand is at unprecedented levels and we now have to move into the next phase of our drought plan to conserve water, mitigate further risk and futureproof supplies.”