Hosepipe Ban for Thames Water Customers Comes into Force, Affecting Over 20 Million

A hosepipe ban for Thames Water customers has come into force bringing the number of people placed under a ban to more than 20 million.

Such measures have been introduced across large areas of southern and eastern England and parts of Wales because successive heatwaves have left water supplies under strain.

But while spring and early summer have been relatively dry for much of the UK - with temperatures regularly exceeding 30C - winter was much wetter than usual.

This means hosepipes cannot be used for watering gardens, washing vehicles and windows and filling pools.

It has raised questions about how effectively water resources are being managed, and whether the UK is prepared for drier summers expected with climate change.

So how is your area doing and how close are you to a drought?

There is no single definition of drought, but it is ultimately caused by a prolonged period of low rainfall, which has knock-on effects for nature, agriculture and water supplies.

Environmental bodies in each UK nation decide whether to declare drought or water scarcity based on an assessment of current water levels and long-term weather forecasts.

Both of these states can trigger a hosepipe ban.

Drought is a lack of precipitation, whereas water scarcity is about a mismatch between water supply and demand - so it is not just about the weather.

This summer, bans have been introduced to manage high water demand.

Large parts of England are currently in "prolonged dry weather" status - the category below drought - according to the Environment Agency.

So far, eight UK water companies have announced hosepipe bans, seven in England and one in Wales.

Prolonged dry weather has been declared in East Anglia, the West Midlands, Devon, Cornwall and the Isles of Scilly, Lincolnshire and Northamptonshire, Hertfordshire and London, Wessex, Thames, and Solent and the South Downs.

The remaining parts of England, mostly in the north, remain in "normal" status.

In Wales, areas across the north and south-east have been escalated from normal to prolonged dry weather status, according to Natural Resources Wales, while there are no official droughts currently in Northern Ireland.

Scotland does not declare droughts but monitors "water scarcity".

Several areas in eastern Scotland are in "moderate scarcity" but none are in the most extreme category of "significant scarcity".

Our three main sources of water are rivers, reservoirs and from deep underground.

Following the hot, dry weather, river flows were low in June for parts of the UK.

"Without significant rainfall we could see increasing impacts on wildlife, agriculture and water resources as the summer progresses," said Steve Turner, a hydrologist at the UK Centre for Ecology & Hydrology (UKCEH).

Reservoirs are a crucial part of water supplies and levels in Northern Ireland, Wales and Scotland are all "healthy" and above expected for this time of year.

England's reservoirs are below average levels for the time of year, albeit with some variation across the country.

South-east England relies more heavily on groundwater than reservoirs.

Groundwater originates as rainfall and is naturally stored beneath the surface in the pore spaces and fractures in rocks.

In June, groundwater levels were generally at or just below normal, having been topped up by winter rainfall but depleted by a drier spring in most regions.

But water can flow more slowly through some rock types than others, sometimes taking years to fully respond to current conditions.

These groundwater stores "respond more slowly to changes in the climate than rivers, which is why they provide a useful buffer during periods of drought", said Prof Alan MacDonald of the British Geological Survey.

It is why groundwater droughts in the south of England generally take a longer time to develop but can be longer-lasting if they do occur.

Droughts are complex phenomena, driven by a mix of natural and human causes.

The Met Office expects the UK to experience drier summers on average in future as the world warms, though there has been no clear trend so far.

But rising temperatures can play a more direct role by drawing extra moisture from the soil via evaporation.

"A warmer atmosphere is thirstier for moisture and this can mean water in the soil, rivers and reservoirs are depleted more effectively, leading to more rapidly onsetting droughts, heatwaves and wildfires," said Richard Allan, professor of climate science at the University of Reading.

But there are other factors that determine whether dry conditions lead to water shortages, including how we use water.

In a landmark review into the water sector of England and Wales, water companies were criticised for historic underinvestment in water infrastructure.

As part of plans to address water shortages, the government and water companies are planning nine new reservoirs for England by 2050, in addition to one under construction at Havant Thicket in Hampshire.

But the Environment Agency has warned that measures to tackle water leaks and control water demand - potentially including hosepipe bans and more smart meters - may be needed in England too.

Water companies in Scotland, Wales and Northern Ireland - which are all public bodies or non-profit - also said they were taking steps to secure future supplies.