Heavy rain is forecast for Saturday night and Sunday, bringing the risk of more flooding in England and Wales.
It comes as the extent of the damage caused by last week's floods emerges, with some 130,000 Gloucestershire homes still facing days without water.
Water firm Severn Trent will start pumping water from its flooded Mythe plant near Tewkesbury on Tuesday but it will not be safe to drink.
And Prince Charles has visited some of the areas worst hit by the weather.
Accompanied by the Duchess of Cornwall, the Prince met businesspeople and members of the public in Upton-upon-Severn, Worcestershire, which was completely surrounded by water at the height of the flooding.
Hundreds of people turned out to see the royal couple chat with residents in a street still partly underwater, and stop for a drink at a nearby pub.
Later, visiting badly-hit Tewkesbury, Gloucestershire, the prince paid tribute to the British spirit, saying: "I've seen some obviously disastrous horrors that have affected so many people. What I have found so wonderful is the spirit the people have displayed."
Water companies across the UK have been sending in tankers to help thousands of homeowners whose supplies have been contaminated, and the Red Cross has been delivering food parcels.
A Red Cross appeal for flood victims has so far raised £500,000.
Severn Trent Water says the Army is helping to plan the refilling of bowsers amid complaints that some have been running dry.
At a press conference earlier Chief Constable Tim Brain said six million litres of bottled and bulk water had been supplied to Gloucestershire on Thursday and efforts were being made to step up the number of times the bowsers were refilled to four a day.
He warned residents not to use water bowsers with broken seals after one incident of a person urinating into a container.
Gloucestershire Police said anyone caught causing criminal damage to bowsers, or causing public disorder at water points, would be dealt with "robustly" and could expect a custodial sentence.
However, Chief Constable Brain said there had been few reports of such incidents.
Chief Constable Brain also warned of more heavy rain at the weekend but stressed that it was unlikely to cause the same level of flooding as last week.
Heavy rain is forecast for south Wales and central and southern England on Saturday night and Sunday morning.
The Environment Agency has one remaining severe flood warning in place on the Thames from Eynsham to Sandford-on-Thames in Oxfordshire.
In other developments:
- Gloucestershire County Council said the cost of repairing flood damaged roads would be £25m - equalling the council's total annual road maintenance budget
- Mayor of Gloucester Harjit Gill launched a fund for victims of the flooding, which has already raised £73,000
- Severn Trent has temporarily restored mains water for washing and flushing toilets to about 10,000 homes in the Tewkesbury area.
- Environment Secretary Hilary Benn said the total number of flooded properties could eventually reach 15,000.
Earlier, Gloucestershire fire chiefs warned people not to take risks clearing up flood-hit properties following the deaths of a father and son in the county.
Chief Fire Officer Terry Standing said anyone in Gloucestershire with doubts about removing floodwater should call the service.
It is thought Bram Lane, 64, and Chris, who was in his 20s, may have been overcome by fumes from a petrol-powered water pump at Tewkesbury Rugby Club.
Fire officers said using petrol and electric pumps to remove floodwater could be dangerous.
The Health Protection Agency says the risk of contracting any illness is generally low, but people are advised to avoid coming into direct contact with floodwater.
Meanwhile, Conservative leader David Cameron has been visiting Hull to see how the city has coped since the floods there.
He said the purpose of the trip was to show residents they had not been forgotten and to find out what lessons could be learned for the future.
Environment Agency floodline: 0845 988 1188
SEVERE FLOOD WARNINGS IN PLACE
The Thames: Severe warnings affecting Eynsham to Sandford Lock
Warnings at Little Wittenham have been downgraded
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