Millions of households will have hosepipe bans by Easter, water firms announced today as the Environment Agency warned of "severe drought" in the coming months.
Seven water companies across southern and eastern England are bringing in hosepipe bans from April 5, following two unusually dry winters which have left reservoirs, aquifers and rivers well below normal levels.
The move comes as the Environment Agency said the drought, which has already gripped the South East and East Anglia, could spread as far north as East Yorkshire and as far west as the Hampshire-Wiltshire border if the dry weather continues.
And with sufficient rain to boost low groundwater and river levels unlikely in the coming weeks, a report from the agency said it was "anticipating a severe drought in spring and summer 2012".
The drought is likely to impact on vegetable, fruit and salad growers and livestock farmers, hit wildlife in rivers and wetlands and could prompt woodland fires.
Power stations which need water for cooling and water-intensive industries such as concrete manufacturers could also be affected, the drought prospects report warned.
Southern Water, South East Water, Thames Water, Anglian Water, Sutton and East Surrey, Veolia Central and Veolia South East will all have restrictions on water use in place before the Easter bank holiday.
Last month the water companies warned that hosepipe bans were on the cards, as the Environment Department (Defra) declared the South East had joined most of East Anglia in a state of drought.
Shortly afterwards, the rest of the Anglian region went into drought.
The Environment Agency said rain in March had been welcome but not enough to reverse the impacts of two consecutive dry winters for the affected regions.
It said it was concerned about the situation at Bewl and Darwell reservoirs in Kent, Ardingly in Sussex, Pitsford reservoir in Northamptonshire and Rutland Water.
And the lack of rain had left river and groundwater levels extremely low across southern and eastern England from the Dorset coast to Grimsby - with areas to the west and south-east Yorkshire also at risk of drought.
Industry body Water UK said all seven companies were set to bring in hosepipe bans and would be consulting on who, if anyone, should be exempt from the restrictions - for example vulnerable customers and businesses.
Around 20 million people could be affected by the restrictions, but Water UK said taking steps to reduce use now would mean there was more water available for people and the environment in coming months.
Thames Water is to impose a hosepipe ban on all its 8.8 million water customers in London and the Thames Valley. It acknowledged that the move would not be popular, but it would conserve water and put the needs of families first.
It said groundwater levels in the region were close to the lowest ever recorded, and many tributaries of the River Thames are running very low, particularly the River Pang, which is running at a third of average flows in Berkshire.
The river, home to Wind In The Willows' Ratty, has dried up entirely upstream of Bucklebury for seven miles north to its source at Compton.
Southern Water said it was bringing in a ban on hosepipes and sprinklers for domestic customers in Kent and Sussex, for the first time since 2005/2006.
The use of hosepipes and sprinklers will also be banned for watering public parks and allotments, as well as for filling swimming pools, paddling pools, ponds and fountains.
Anglian Water is imposing its first hosepipe ban for more than 20 years on its 4.2 million customers, but said the move was the "most sensible and responsible action" to safeguard customer supplies this year and beyond.
Peter Simpson, managing director of Anglian Water, said: "Our region has had its driest 18 months for a century, including two dry winters which have robbed us of the rainfall we need to refill rivers, reservoirs and aquifers."
Portsmouth Water said it had not been as severely affected as other areas but was still calling on customers to show "voluntary restraint" in their water usage in the coming months, as it warned a lack of rain could lead to hosepipe bans.
Environment Secretary Caroline Spelman said: "These temporary restrictions will help protect the public's water supply in the areas most affected by the record low levels of rainfall we have experienced over the last 17 months.
"We can all help reduce the effects of drought by respecting these restrictions and being smarter about how we use water."
The move to bring in hosepipe bans was welcomed by environmental groups and angling organisations, which said water demand during dry conditions put a huge strain on wildlife, rivers and the countryside.
They renewed their calls for more water metering and changes to the processes for abstracting water from rivers to use water more efficiently and protect nature.
The National Farmers' Union said drought could have significant impacts on production of vegetables such as potatoes in some parts of the country and some growers were reporting production was being "seriously affected".
But NFU director of corporate affairs Tom Hind said it was difficult to predict what impact this would have on prices.
Growers were taking steps to be "smart" with water use to meet orders, and increased production in wetter parts of the country could compensate for some shortfalls of potatoes and other vegetables in drought-stricken areas, he said.
"There's a big gap between the prices farmers and growers receive for their crops and retail shelf prices, so there's no immediate cause for alarm by consumers," he said.