Shortages and hosepipe bans are likely next year unless something nearer to normal rainfall resumes over the winter.
"The South-east of England will face a very difficult summer if we do not get at least 75 per cent of normal winter rainfall," said Dr Geoff Mance, the agency's water management chief.
The drought is patchy. Partly this is because of the wet summer, with the well above average rainfall of May, June and August sharply cutting demand for garden watering. And after years of criticism, water companies have become more adept at coping with scarce resources.
Most of them are reporting that their reservoirs are actually fuller than they would normally be at this time of year, and levels are much higher than they were in October 1996 and 1995. Exceptions are in the Thames and Anglian regions. But September and October have had below average rainfall, giving a poor start to the key autumn and winter period when the nation's water resources are replenished. Across the country, from the south coast through East Anglia and up to the Scottish borders, groundwater in the aquifers remains at exceptionally low levels. Groundwater provides two-thirds of water supplies in South East England, half in East Anglia, and one-third in the Thames Valley, and the agency's report says water resources in these areas are "precariously balanced".
The Environment Agency has 35 "indicator" rivers whose flow is constantly measured. All but one of these is flowing at below average levels for this time of year, and 23 are under half the average. Hosepipe and sprinkler bans are still relatively rare. The largest of these covers 1.7 million people and was imposed by the Essex and Suffolk Water Company last June.
Yesterday the firm, which covers parts of east London, Southend, Chelmsford, Lowestoft, Great Yarmouth and surrounding towns and villages, said it did not know when it could be lifted.
Some customers have been alarmed by the company's scheme for recycling sewage effluent into a reservoir, which went into operation last August. The treated effluent is taken from Anglian Water's sewage works at Chelmsford and piped seven miles to a treatment plant, where ultra-violet light is used to disinfect it. Then it is mixed with water from the Chelmer and Blackwater Rivers, before being pumped into the company's Hanningfield Reservoir.
It only reaches the customers' taps after being filtered and chlorinated when the water leaves the reservoir.
The scheme has given the company an extra 20 million litres a day, equivalent to 5 per cent of its output of drinking water. Dr Roger Griffen, director of customer relations, said: "It's no different to what happens in a large number of rivers, and the water in the reservoir is just as good as it would always have been, if not better."
Several water companies take water from rivers downstream from sewage works. Dr Griffen claimed his company's scheme was fundamentally no different to this, apart from the effluent used by Essex and Suffolk being given the extra, ultra-violet disinfection treatment.
"On the whole our customers are taking it quietly, but there are some that are concerned and we're trying our hardest to give them confidence," said Dr Griffen.
The agency is objecting to Anglian Water's bid to take extra water from the rivers Nene and Ouse to help refill two reservoirs.
The company is applying for drought orders which, if granted, would allow the rivers' flow to drop below the usual legal minimum from December to next May.
But the agency says Anglian cannot yet justify the harm this will do to the environment and other water users.Reuse content