Drought has been declared in a further 17 English counties, with the Environment Agency saying water shortages could last until Christmas or beyond.
Environmental experts said dry weather over the past few months had left some rivers in England exceptionally low and had now extended the country's "drought map" into the Midlands and the South West.
While Environment Agency officials stress that public water supplies are unlikely to be affected by the ongoing drought, they ar reiterating calls from consumers to combat the dry conditions by using scarce water wisely.
Warning of the prospect of the current drought stretching into 2013, Trevor Bishop, head of water resources at the Environment Agency, said: "A longer term drought, lasting until Christmas and perhaps beyond, now looks more likely.
"While we've had some welcome rain recently, the problem has not gone away, and we would urge everyone - right across the country - to use water wisely now, which will help to prevent more serious impacts next year."
The Agency, which is liaising with businesses, farmers and water companies to meet the challenges of a continued drought, had already declared drought zones in London, the South East, East Anglia and parts of Yorkshire.
Exceptionally dry conditions across the major part of England are the result of a lack of rainfall over the past two winters, which has left rivers and ground waters depleted.
A spokesman for the Environment Agency said: "While public water supplies in these areas are unlikely to be affected, the lack of rain is taking its toll on the environment and farmers - causing problems for wildlife, wetlands and crop production.
"The Environment Agency is urging businesses, water companies and consumers to all play their part by using water wisely, to help conserve precious water supplies."
In the Midlands the Environment Agency has rescued fish from the River Lathkill in Derbyshire after it dried up, and the Rivers Tern, Sow, Soar and Leadon reached their lowest ever recorded levels in March.
Meanwhile, rivers in the South West are also suffering and nationally important chalk streams, such as the Hampshire Avon and the Dorset Stour, which support rare trout and salmon species, are described as exceptionally low.
While rain over the spring and summer will help to water crops and gardens, it is unlikely to improve the underlying drought situation, according to experts.
It was hoped that a prolonged period of rainfall between October and March - known as the winter recharge period - would prevent widespread drought, but parts of England received less than 60% of the average winter rainfall, and water supplies have not been replenished.
Commenting on today's news, Environment Secretary Caroline Spelman said: "As more areas of the UK move into drought it is vital that we use less water to protect the public's water supply in the driest areas of the country.
"It is for everyone to share the responsibility to save water. We are asking everyone to help by using less water and starting now."
Experts are now hoping for a steady rainy winter in 2012/13 to restore rivers and groundwaters, but the Environment Agency is working with the water industry to put plans in place now to deal with the prospect of a third dry winter. Water companies are looking at where they may be able to get more water, options to share water across company boundaries and how they can reduce leakage further.
The Agency is urging all water users to save water now, to help prevent more serious shortages and environmental impacts next year.
The Environment Agency last week called on businesses to join householders in saving water, and is continuing to press water companies to demonstrate that they have stepped up their publicity campaigns to encourage people and businesses to conserve supplies.
Officials are also stepping up river monitoring and working to help farmers top up their storage reservoirs.
- The new official drought zones are Nottinghamshire, Leicestershire, Derbyshire, Staffordshire, West Midlands, Warwickshire, Shropshire, Worcestershire, Herefordshire and Gloucestershire, Cornwall, Devon, Dorset, Somerset, Bristol, South Gloucestershire, parts of Hampshire, and most of Wiltshire