To the west of Andover, there are around half a dozen small villages connected by a chalk stream called the Pillhill Brook.
You don’t have to sit by the river for long before you spot trout swimming along and the stone cottages, thatched roofs and open greens make the villages – collectively known as the Pan Parishes – some of the most beautiful in the region.
However, beneath the picturesque landscape, the area experiences high groundwater levels, especially over the winter months. This means that, when combined with an aging sewage network, groundwater regularly seeps into our pipe network.
When groundwater leaks into sewers, which were designed to only take water from sinks, toilets, showers and kitchen appliances, it’s known as infiltration. This can result in the sewers being overwhelmed and forced to release excess water into local watercourses, to stop homes, businesses and schools from flooding.
As chalk streams are extremely rare, with only 210 in the world and over 85 per cent of those located in southern and eastern England, it makes protecting the environment around the Pillhill Brook extremely important.
During the winter months Southern Water has deployed dozens of tankers to pump diluted sewage out of the network in a bid to protect the chalk stream. While it’s good news for waterway, it can cause disruption to traffic because of the area’s single-track roads and is also an expensive and carbon intensive operation.
That’s why, together with the local community, we’ve been working to stop the disruption to the villages, reduce the risk to the environment and build a community space that generations of residents will be able to enjoy.
Over the past six months, we’ve conducted surveys to identify and repair the sewage pipes in the most affected areas. We’ve already surveyed close to 50 per cent of the network, which stretches 36km, and have resealed many of the damaged pipes.
But our work doesn’t stop there - it’s not just a case of ‘mend and make-do'. We know innovation and nature-based solutions can unlock the answers we need to prevent groundwater infiltration and we’re exploring ways to use these.
Firstly, we’re using a product called Tubogel that can be added to broken or fractured sewer pipes to seal them without the need to dig holes or insert liners. It works by inserting two liquids down into the pipe which harden when they touch each other and solidify to make an enduring stone seal around the leak. It is a reliable, long-lasting solution that is easy to use, especially when access to sewer systems is difficult, and cuts out the need for expensive and disruptive civil engineering works.
And secondly, our team is considering if natural solutions that reduce floods, improve water quality and provide more habitats for wildlife would be appropriate in the area.
We’re working with our customers to make sure the improvements to the network cause minimum disruption and that the local environment is protected. It is important to us all that we protect and enhance the beautiful Pan Parish villages, both now and into the future.