One third of a million people in the west of England will remain without clean running water for at least a week as a result of the worst floods to have struck the UK in the last 60 years.

Severn Trent Water said this morning that 350,000 customers would remain dependent on 3 million litres of bottled water delivered by the Army each day, and on a fleet of 900 mini-tankers parked in flood-stricken locations to dispense drinking water.

Gloucestershire County Council said several bowsers were being vandalised amid frustrations over the water supply.

With supermarket stocks running low as far as Bristol, hundreds of people gathered outside a Tesco supermarket at Quedgeley in Gloucester, awaiting the arrival of thousands of bottles of water. The water was set to arrive with an Army escort to ward off looters.

Shocking news: Britain’s a wet country

British summers weren’t always as wet as this year’s, but some were worse. 1912 was the wettest and dullest on record

Related Links

• Tales from the floods

• Rwandans ask Cameron: why aren't you in Witney?

• How to clean up after your home has flooded

Multimedia

• Video: UK under water

• Pictures: 2007 floods

Army Brigadier Jolyon Jackson urged the public to stay calm and added: “There is enough water for everyone.”

Meanwhile, residents along the Thames Valley were warned to remain on high alert for the next two days to protect their homes from the river, which it is feared has yet to reach its high water mark.

"Things are better than they were," said Dr Tim Brain, the Chief Constable of Gloucestershire, who has been co-ordinating the multi-agency response to the unprecedented flooding disaster which began with Friday's torrential downpour.

"But that is a marginal statement, and we are far from out of this as an emergency. We have still large areas of flooded fields and villages and isolated communities around the county still, principally around the confluence of the Avon and Severn, and we have this major issue of water supply to over half the county of Gloucestershire. We are far from out of the woods."

Efforts were beginning this evening to pump the water out of the Mythe water treatment works in Tewkesbury, which formerly supplied drinking water to tens of thousands of homes in Gloucestershire. Firefighters and the army will erect heavy flood barriers in a sealed wall around the site, so that they can start pumping the water out.

It is hoped that Severn Trent Water engineers will soon be able to get into the higher parts of the site, to start assessing the damage to flooded tanks.

"We cannot, at the moment, say when the site will be open and running again, or improve on the estimate already given that it will be seven to 14 days," said Alan Payne, Severn Trent's general manager of water services.

Severn Trent had earlier risked a backlash by telling investors in the City there was no reason to change its profits guidance for the coming year, despite the cost incurred by the flooding. In a short statement, Britain’s second-biggest water company said there had been “no change in outlook”.

The group is expected to make around £300 million in the year to March 2008. Last month Severn admitted it had missed leakage targets for the second year in a row. It loses more than 525 megalitres of water a day - the equivalent of 218 Olympic-sized swimming pools - through holes in its pipes.

The emergency services estimate that at least 10,000 people remain flooded out of their homes in the Midlands, East Anglia and Thames regions.

People living beside the Thames in Berkshire remain on high alert as a surge of water heads downstream, but the Environment Agency was today scaling back the level of its warnings after the expected surge in Oxford and Abingdon during the night was lower than predicted, and there were no reports of any more people being flooded there.

Levels downstream of Abingdon in the Berkshire village of Pangbourne, where more than 400 homes were affected over the weekend, were being monitored, but so far the Thames was said to be running within its banks. The focus will move on to Reading in the early hours tomorrow, and at Windsor on Thursday.

Tim Abbott, an Environment Agency spokesman, said that homeowners had had several days' warning and should now be prepared. He said: "We are now expecting the Thames to peak in Pangbourne, Purley and the Reading area in the early hours of Wednesday. There could be flooding of some properties.

"Levels in Reading, however, are not expected to be anything what we have had in Oxfordshire. At the moment it is looking like any flooding will not be as bad as in 2003."

This evening, the threat of more flooding appeared to be receding for the thousands affected in Gloucestershire, the worst-hit county, after levels of the river Severn slowly started to fall.

During the night the Severn peaked 2ins below the level of the quay which protects Gloucester City Centre, and by this afternoon was said to have dropped back a few inches.

Levels in Tewkesbury, the market town where a wall of flash flooding rushed through the streets "like a train" at 10pm on Friday night, are falling at the rate of a mere 8ins a day, but it is expected to be some time before the worst-affected areas are free of water.

Dr Brain paid tribute to the 250 firefighters, service personnel and engineers who had worked without ceasing to maintain the flood defence barricades protecting Walham electricity sub-station near Gloucester, and to pump out any water that did get through. They had saved half a million homes from being plunged into darkness, he said.

The Castlemead electricity sub-station, which had been switched off when the floodwaters got in, has now been put back on line, enabling power to be restored to all but 250 homes.

Much of Tewkesbury, which lies close to both the rivers Avon and Severn, and other communities inundated in the floods remained under water today.

The British Red Cross charity this afternoon said its National Floods Appeal for victims of the freak weather had raised more than £300,000 in its first hour, mainly thanks to corporate donations from Tesco, the Halifax and GlaxoSmithKline.

The charity has dozens of volunteers working in the flood-affected areas, distributing food and water via its boats and a Unimog off-road vehicle, as well as staffing a round-the-clock helpline.

Sir Nick Young, the charity's chief executive, said: "It was shocking last night going through Gloucester and Tewkesbury - these awful scenes of people huddled around candlelight in the upper floors of buildings.

"It was ridiculous to see young children playing in the water as if it was the beach at Blackpool. It is unsafe water, absolutely filthy, polluted by sewage, and people really need to be advised to stay out of it."

In addition, in a statement to the House of Commons this afternoon, the Environment Secretary Hilary Benn said that the Government would supplement its flood recovery fund, out of which local councils can apply for emergency cash, with a further £10 million. He added that Ministers may consider applying for extra funding from the European Union once a firm financial estimate of the damage caused by the floods had been reached.

Mr Benn also promised that flood protection measures, including the location of water treatment plants, would be examined as part of the independent review he set up yesterday.

It came after Dr Brain earlier today said that flood protection in Britain needed a radical re-examination.

"We need to look at the strategic situation of utilities in this country: water, fuel supplies, gas and electricity," he told BBC Radio 4's Today programme. "This needs to be looked at in a radically different way in order to guarantee supplies on a national grid basis."

Tonight, the Queen issued a statement in which she paid tribute to the work of the emergency services.

“Please extend my sympathy to all the many people whose homes have been damaged, livelihoods threatened, or who have been affected by the water and power shortages," she said.

“May I also express my continued admiration for the emergency services, military personnel, local authorities, and volunteers working tirelessly and selflessly to bring people to safety and avert further damage.

“To all those concerned, I send my heartfelt thanks.”

Forecasters predict better weather today but more showers this week and heavy rain on Thursday, and the Environment Agency has warned that if these are substantial it would not take much for river levels to start to rise again.

August may at long last offer some sunshine to a washed-out Britain.

Explore UK News

• Crime News

• Education News

• Health News

• Science News

• Scotland News

Times Recommends

• Don't despair: great players learn from defeat
• Pope clears way for Cardinal Newman sainthood
• Ecclestone: despots are underrated