Real-time monitoring to protect chalk stream
A scheme to provide real-time pollution monitoring along the entire length of a chalk stream is believed to be the first of its kind in the country.
Nearly 20 sensors, known as sondes, have been placed into the River Test to continuously measure key indicators of water quality.
The collaboration between Southern Water, local communities and campaigners follows recent concern over pollution levels.
It's hoped the continuous monitoring will give a better understanding of the types of pollution and where and how it's entering the river.
"We have, from source to mouth, the entire River Test and major tributary areas covered by this monitoring equipment" explains member of the Pan Parish River Pollution Forum and local Lib Dem councillor, Geoff Cooper.
"As far as we know it's never been done before in the UK and that's why it's such a ground-breaking and exciting moment."
The monitors provide half hourly updates of dissolved oxygen, ammonia and water temperature levels. The information can be accessed by campaigners and river keepers alike.
It's hoped within the next year it will also be available to the public.
"I've been a river keeper in Hampshire for 10 years but I grew up looking after a river in Yorkshire" says Seth Crosswaite, river keeper at Houghton Lodge.
"What you want to see in a chalk stream is nice clean gravel. That's what the fish need to spawn on."
"All those monitors down that river will measure it in real-time. So if we get a pollution incident we can look above stream and down stream of it. Above stream to see where it is and downstream to see what effect it is having on the river."
Concern about the health of the River Test grew in 2024 when heavy rain saw overflow sewer outlets spill into the river during what Southern Water called "exceptional circumstances".
According to Geoff Cooper that protest proved a turning point.
"That made Southern Water realised just how angry people were."
"They opened their doors to us and gave us the opportunity to work collaboratively together to find solutions to better understand the quality of our rivers."
Southern Water says it's investing 84 million pounds improving water quality on the Test - 28 million pounds at Fullerton Waste Water Treatment Works.
The company says the voluntary monitoring scheme puts it ahead of the game and prepares the way for forthcoming legislation.
"It will look at inputs from not just our assets but from all other sectors that operate along the river corridor such as agriculture" explains Joff Edevane, Environment and water quality lead for Southern Water.
"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."
For local residents, campaigners and river keepers alike it's hoped the new monitors will play a crucial role safeguarding a much loved and prized chalk stream.
Geoff Cooper hopes a better understanding of the challenges it faces today will help protect it for years to come.
"The River Test is the gold standard of chalk streams and it's crucial that we, as custodians of it, do everything we can to protect it for future generations.
<small>Source: BBC Science</small>
