Following what it describes as a challenging winter, Southern Water has announced is investing £11 million in Hampshire to help protect homes, reduce disruption and strengthen the sewer network against the impacts of groundwater.

The investment follows a difficult groundwater season across December, January, February and March, when prolonged and heavy rainfall led to exceptionally high groundwater levels.

The areas to get the investment are in the north of the county, including the village of St Mary Bourne, located near Andover, which will benefit from an investment of £5 million. The work will see teams sealing sections of the sewer network reducing the amount of groundwater able to infiltrate the network during periods of high groundwater levels.

Other schemes are also underway nearby with £3.5 million being spent to seal more than 15km of the sewer network in Penton Mewsey and Appleshaw and £2 million to be spent at Goodworth Clatford on a similar scheme.

The water company said it is also working ahead of the next groundwater season on improving every aspect of its performance to minimise the impact tankering and other work has on communities.

What is groundwater and how it affects the network

The areas impacted by groundwater usually have chalk aquifers that act like giant sponges - they soak up rain then release it slowly for weeks and months. That raises the water table, pushing water back towards the surface and forcing it into sewer pipes and manholes, reducing capacity and putting networks under strain long after the storms pass.

Director of Wastewater Operations Southern Water, George Taylor said:

“We know just how difficult the last groundwater season was for communities across Hampshire, especially in places like St Mary Bourne where people experienced real disruption and concern about flooding. We’re sorry for the impact this had and recognise there were times we could have done more to support our customers.

“We’ve listened and learned from that experience, and this investment is about taking practical action to better protect homes and communities in the future. By sealing and lining our sewers across Hampshire, we can reduce the amount of groundwater entering the network, helping to lower flood risk and improve resilience during prolonged wet weather.”