Families with large gardens or swimming pools could face higher water bills, the Mail understands.

To conserve water supplies and bring down bills for the poorest households, ministers could hit bigger properties with higher tariffs for excessive use – effectively a ‘tap tax’.

Ofwat, the water regulator, has previously called on companies to consider charging customers a premium for hot tubs, swimming pools or extensive sprinkler systems.

It has also suggested companies look at seasonal charging to help lower bills in winter – or at whether bills could be reduced for homes with water butts and permeable driveways.

The Mail understands ministers are looking at similar proposals, and hope that any extra money raised could be used to cut the bills of the poorest households on a social tariff.

It is unclear, however, how water companies would identify which households use large amounts of water to fill a hot tub, without penalising large families.

Affinity Water, which supplies households in some parts of the south east, is currently trialling a ‘rising block tariff’, which charges more per volumetric unit of water for each subsequent block of water used. 

Ministers are also looking at changing building regulations to encourage new homes to recycle ‘greywater’ – wastewater from baths, showers, washing machines, dishwashers and sinks.

Instead of using potable water to flush the toilet or water the garden, using greywater can save around 70 litres of drinking water per person per day in domestic households, research suggests. 

The Government is looking at ways to reduce water usage, amid warnings the UK is facing a shortfall of water within the next 15 years.

A report by think-tank Demos, commissioned by Affinity Water, last year found that the country faces a shortfall of 200 million litres of water in 2038. 

It recommended more ambitious targets for new homes for water efficiency – such as wider use of greywater – and exploring the use of rising block water tariffs.

Both ideas will be looked at as part of the Government’s wider review of the water sector. No decisions have been made and discussions about various measures are in early stages, officials stressed.

In 2022, Ofwat called on water firms to look afresh at how bills are set and pilot new ways to help households that need it most. It said: ‘Changes could... help to encourage water efficiency by reducing overall water use.’