People caught fighting over water supplies or damaging bowsers in flood-hit Gloucestershire will be jailed, police have warned.
Thousands of homes are still without mains water
Normally criminal damage or threatening behaviour would be dealt with by community-based sentences.
But Chief Constable Tim Brain has said offenders will be treated the same as those guilty of road rage assaults.
About 130,000 homes in the county are still without water. Severn Trent hopes to pump in supplies next week.
Gloucestershire police have said they have received about ten reports of criminal damage to bowsers and one unconfirmed report of urine in one of the containers.
Magistrates will consider a term of between 21 and 28 days for a first offence after a guilty plea for crimes relating to the limited water supplies.
Assaults against water company staff, police officers, volunteers or army personnel will also result in jail.
Anyone caught stealing water for resale is likely to face tough penalties. Ch Con Brain said: "Fighting over water supplies will be treated in the same manner as 'road rage' assaults.
"In these cases short custodial sentences have been approved by the appeal courts."
The measures are being adopted by all magistrates in Gloucestershire, and are supported by the local resident Crown Court judge.
Water for washing and flushing toilets could be in homes across the county next week.
A spokesman for Severn Trent Water said the company expected to begin pumping water from the plant on Tuesday.
Operations manager Fraser Pithie said: "When the output starts, it will take a number of days longer to fill the system up.
"Then when that water arrives at people's taps, it will be 'do not drink'. It will be for sanitation," he said.