This comes as experts warned of a potential looming drought across the UK after record-breaking temperatures last month. Thames Water joins Manx Water, Welsh Water, Southern Water and South East Water in imposing restrictions on water usage by its customers.
Yorkshire Water previously announced that restrictions will apply to its customers on August 26, while South West Water said on Monday that limits will be placed on its consumers from August 23.
The announcement from Thames Water means that from August 24, 15 million people in the south of England will be subject to a hosepipe ban.
It is the largest-scale hosepipe ban to come into force so far.
Thames Water said earlier this month that a ban was to be announced in the “coming weeks” in line with Met Office predictions.
A spokesperson for the utilities company said: “We have a dedicated team of analysts and scientists monitoring our water resource levels at all times.
“The team takes into consideration a number of factors including Met office forecasts, reservoir storage levels and expected customer demand.
“When considering implementing a Temporary Use Ban [TUB] we have to balance the impact on our customers and the environment. To inform our decision making we work to our Drought Plan.
“We have been preparing for summer since the winter, making good use of abstractions earlier in the year to fill our reservoirs in London.”
READ MORE: Bloke with massive wedgie found sleeping half-naked on car
They added later in the statement released on August 9: “Our aim is always to ensure that we will have enough water to supply our customers, regardless of the weather.
“Given the long term forecast of dry weather and another forecast of very hot temperatures coming this week we are planning to announce a temporary use ban in the coming weeks.”
They continued: “The timing is not confirmed due to a number of operational and legal procedural requirements but we will be updating our customers, partners, regulators and stakeholders at the earliest time to ensure a coordinated approach.
“In the meantime we continue to urge our customers to only use what they need for their essential use.”
Storm tracker LIVE: ‘Danger to life’ Britons prepare to evacuate [LIVE]
Cycle lanes torn apart by readers for ‘increasing congestion’ [INSIGHT]
POLL: Should the energy price cap rise be scrapped? [VOTE]
Southern Water’s hosepipe ban came into effect for Hampshire and the Isle of Wight on August 5, and South East Water customers in Kent and Sussex fell under a similar restriction in August 12.
The Thames Water ban brings the total number of affected Britons to around 24 million.
Some experts have suggested water companies may have resisted putting the hosepipe bans in place to avoid irritating customers.
Mark Lloyd, the chief executive of the Rivers Trust, told The Guardian: “It is unpopular – gardeners complain – and there’s an issue of trust as well.
“People are pointing out there’s a lot of leakage from water company pipes and people say: ‘Well, you fix your leaks and I’ll stop using my hosepipe.'”
UK water consumers may face drought conditions until the autumn, environmental groups have warned.
Estimates say reduced water flows may last until October.