Southern Water is installing nearly 20 monitors along the rivers Test, Itchen and Blackwater, offering half-hourly updates on the health of the chalk streams.

The monitors – known as sondes – sit in the water and relay data on levels of parameters such as dissolved oxygen, ammonia and water temperature to a central platform, building a comprehensive picture of factors affecting water quality.

Southern Water said it is funding the project as a voluntary initiative in collaboration with the Pan Parishes River Pollution Forum and local riverkeepers, who have chosen the locations of the sondes and are monitoring the data. It will be made publicly available within the next 12 months.

Hampshire riverkeeper Seth Crosswaite commented:

“Having a sonde in the river makes a huge difference and it’s not just one we’re talking about - it’s 19 throughout the full length of the Test. These tell us in real-time what’s going on with the river, so if we get a pollution incident we can see straight away where it is. It’s not just water companies [causing pollution] it’s agriculture, road run-off etc. Working together we hope to restore this river back to the way it was 100 years ago.”

Government legislation requires all water companies to install and publish data taken from river monitors upstream and downstream of their outfalls by 2030. However, as Test Valley Borough councillor Geoff Cooper, a member of the Pan Parishes River Pollution Forum, explains, the project goes far beyond those requirements.

Geoff Cooper said:

“Southern Water has committed to going so much further than the government legislation requires. We’ve gone faster, we’ve gone quicker, and we’ve got more monitors than the Government legislation requires. That’s a testament to the collaboration that myself and other members of the Pan Parishes River Pollution Forum have had with the team at Southern Water.”

The project is part of the water company’s £160 million investment in improving water quality and enhancing the local environment in Hampshire.

Southern Water’s Environment and Water Quality Lead Joff Edevane said:

“This project is a great example of our collaborative work with Hampshire riverkeepers and the Pan Parishes River Pollution forum. We’ve listened to what they want and now we’re working together to help achieve it.

“The sondes give riverkeepers joined-up daily insight into what’s affecting water quality in these rivers, which is a great starting point to be able to improve it.

“This isn’t just about our outfalls - numerous factors affect water quality, from agricultural runoff to illegal connections. But we know we need to do better when it comes to discharges and storm overflows. That’s why we’re also investing more than £84 million around the Test and £78 million near the Itchen upgrading infrastructure, lining sewers and reducing storm overflows.”