Southern Water has said it is using advanced radar sensors beneath more than 20,000 sewer manholes to prevent pollution incidents.

The UK's first digital sewer network has led to a significant reduction of incidents by 35 per cent during the past year.

The programme’s success will see an additional 10,000 monitors installed.

In July last year, blockages from substances such as fat, oil, grease and ‘unflushables’ like wet wipes and sanitary products, accounted for 28 per cent of pollution incidents.

Radar devices called sewer level monitors are strategically placed in high-risk areas beneath sewer manholes, consistently measuring wastewater levels.

Employing machine learning assists in understanding the typical flow behaviour during various weather conditions and typically busy 'wastewater rush hours'.

If levels begin to rise, it signifies a potential downstream blockage which allows the Southern Water teams to proactively combat the issue before it develops into a serious problem.

Utilising the monitor system efficiently also allows Southern Water to identify and prioritise regions prone to groundwater flooding, enabling focused efforts to seal sewers and customer pipes against water infiltration.

Alex Saunders, from the firm, said: "On top of the important cut in pollution incidents is the impact on customers - 498 garden floods have been prevented and better yet 48 homes have been spared the misery of internal sewer flooding."