Heavy rain is forecast for Saturday night and Sunday, bringing the risk of more flooding in England and Wales.
Gloucestershire Police have said anyone caught damaging water containers or causing public disorder at water points could expect a custodial sentence.
Residents have been warned not to use water bowsers with broken seals after someone urinated into one of them.
About 130,000 homes in Gloucestershire are still without running water and the situation is likely to last for days.
Gloucestershire Police said people causing problems would be dealt with "robustly", but Chief Constable Tim Brain added there had been few reports of such incidents.
Mr 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.
Heavy rain is forecast for south Wales and central and southern England on Saturday night and Sunday morning.
But Mr Brain said it was unlikely to cause the same level of flooding as last week.
Water firm Severn Trent will start supplying water from its flooded Mythe plant near Tewkesbury on Tuesday but it will not be safe to drink.
Prince Charles has visited some of the areas worst hit by the weather.
He and the Duchess of Cornwall went to Upton-upon-Severn in Worcestershire and Tewkesbury in Gloucestershire.
The Prince of Wales said: "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 said the Army was helping to plan the refilling of bowsers amid complaints some have been running dry.
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.
The Environment Agency has one remaining severe flood warning in place, on the Thames from Eynsham to Sandford-on-Thames in Oxfordshire.
Gloucestershire fire chiefs have warned people not to take risks clearing up flood-hit properties following the deaths of a 64-year-old man and his son in Tewkesbury.
The Health Protection Agency said the risk of contracting any illness is generally low, but people are advised to avoid coming into direct contact with floodwater.
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
Have you been affected by the floods? How are the drinking water supplies? The BBC would like to hear from anyone affected by the floods. Please use the form below to tell us about your experiences.
You can send pictures and video to: firstname.lastname@example.org or to send via MMS please dial 61124.Do not endanger yourself or others, take any unnecessary risks or infringe any laws.
The BBC may edit your comments and not all emails will be published. Your comments may be published on any BBC media worldwide.