The water company has a fleet of tankers as well as mobile pumps working round the clock throughout key points in the region to deal with the problem caused by local drainage networks and flood defence systems being overwhelmed.
Drainage systems are the responsibility of local councils and the Environment Agency but Southern Water maintains a duty to keep the sewer network operating to prevent sewage overflowing.
Geoff Loader, director of communications, said: “When drainage systems and flood defences, which are the responsibility of other agencies, are unable to prevent flooding our sewers are at risk.
“The flood water gets into the sewers and they are simply not there to carry this water. Therefore, we have to use tankers and mobile pumps to try to keep them operating and dealing with the wastewater from homes and businesses – the job they are designed to do.”
In some areas the water table rose 10 metres in five days, causing underground springs to reach the surface, overwhelm drainage networks and flood the sewers. In others parts of the region overflowing rivers have caused a similar issue.
Loader added: “In the past year alone, we have spent more than £4 million to seal sewers and manholes to prevent flood water getting into them. More of this work is planned but it is important to realise this will deal only with a symptom, and not the cause, of the flooding.
“That is for other agencies to look at and we are committed to supporting their plans to prevent this flooding in the future.”