Restoring the rivers of the South Downs National Park – what’s been done and what we need to do

September 22, 2023

The South Downs is internationally-renowned for its quintessentially English countryside, pretty chocolate-box villages, flower-rich chalk grasslands and stunning white cliffs.

Perhaps less known are the network of rivers and streams that crisscross this amazing landscape – yet they really are the beating heart of a complex ecosystem that relies on flowing freshwater!

The National Park’s rivers and all their tributaries are life-giving arteries, supporting an incredible variety of plant, fish, bird, amphibian and insect species.

For this very reason river health is a key priority of the National Park Authority, which has been working for many years with landowners, farmers, key stakeholders and visitors to encourage good river management and reduce polluting run-off in order to help nature thrive.

To mark World Rivers Day this September, we’ll look at why rivers are important, what we’ve done and are doing to help them, the challenges our waterways face and why they need our help.

Why rivers are important

There are seven main rivers that run through the National Park – the Ouse, Cuckmere, Adur, Arun, Rother, Meon, and Itchen – and, while there are lots of similarities, each have their own unique ecology and biodiversity.

As well as these rivers, there are a network of over 100km of crystal-clear chalk streams in the South Downs, many of them fed by springs rather than rain. These chalk streams are internationally rare – there’s only about 200 of them in the world!

Carry out a survey and you’ll be amazed what you can find, in particular the sheer breadth of species diversity. Kingfisher, otter, wigeon, water vole, bullhead, lapwing, eel, brown trout, and the endangered white-clawed crayfish, to name but a few, and that’s before you’ve started looking at the scores of insect species.

These rivers are among the richest freshwater ecosystems in the UK and the picturesque river valleys are an integral part of the landscape and local communities. Hydrological systems are ultimately all connected, so healthy rivers and streams means healthy soils, better crops, healthy trees, more biodiversity, cleaner drinking water and healthier seas and oceans. The National Park provides drinking water to over 2m people along the south coast, so it’s in everyone’s interest that our waterways are in good condition.

While the biodiversity today might seem impressive, step back 100 years and our rivers would have been buzzing with much more life. Across the UK, over three quarters of rivers fail to meet the required standards for river health and climate change is putting even more pressure on these delicate freshwater habitats. In some cases, biodiversity is merely surviving, rather than thriving, and that’s why rivers really do need our help.

Successes since the National Park was created

The River Meon in Hampshire has seen the first green shoots of recovery and is an example of what can be achieved with strong partnership working.

A species you may be lucky enough to spot is the water vole, an animal that was decimated due to predation by the non-native species, the mink.

Water voles are essentially ecosystem engineers – their burrowing and feeding behaviour along the edges of watercourses creates the conditions for other animals and plants to thrive.

The water vole has made a remarkable comeback in the South Downs National Park thanks to the work of the Meon Valley Partnership. Over a period of six years, a total of 2,833 water voles were released to 30 locations along the stretch of the river.

The project ticks every box for why the South Downs became a National Park – bringing volunteers, landowners and the local community together to care for landscapes and support wildlife.

The resurgence of water vole has improved the overall health of the river and co-incided with the return of another species – the otter. It’s believed there are now three breeding females on the river.

The Meon Valley Partnership, which includes the SDNPA and other partners such as the Environment Agency, Portsmouth Water and Hampshire and Isle of Wight Wildlife Trust, has worked with landowners, local fishing groups, and volunteers to help restore river banks and encourage more nature-friendly land management.

Meanwhile, The Rother Revival project, with support from The Sussex Lund grant programme and working with Leconfield Estates, is focusing on enhancing a stretch of the western Rother in West Sussex.

The work involves lowering the river bank to help reconnect the river with its floodplain, narrowing the channel to increase flow and introducing woody debris and newly-planted trees to provide valuable habitat for wild fish. The work is helping to reduce erosion and sedimentation – something that will benefit spawning wild trout, which need clear well-oxygenated water and clean gravels to lay their eggs.

Wild trout are excellent indicators of the health of a river – and where they thrive you can be sure that other wildlife will thrive too!

Current projects that will benefit wildlife and people

Work to establish a new wetland habitat in the National Park is well under way, with diggers on site as part of a plan to realign the Cockshut Stream.

The partnership project will bring an array of biodiversity benefits and reduce the risk of flooding in the Lewes area.

Adjacent to the Lewes Brooks, the Cockshut is a 3km long chalk stream that flows from springs at the foot of the South Downs in Kingston, eventually joining The River Ouse before flowing out to sea. The Cockshut is currently clogged up by a non-native invasive plant called parrot’s feather.

By realigning the stream, the old channel can be filled in, eradicating the problem plant, and the stream will flow into a newly-created 6.8 hectare wetland.

Lewes District Council, Ouse and Adur Rivers Trust, Lewes Railway Land Wildlife Trust and South Downs National Park Authority are working together on the Cockshut Stream restoration and expect to complete the project by autumn 2023.

Jan Knowlson, Biodiversity Officer for the National Park, says: “Our rivers across the country are in poor condition through pollution and habitat degradation, so this is a fantastic project to enhance one of the National Park’s rare chalk streams.”

Councillor Emily O’Brien, Cabinet Member for Climate, Nature and Food Systems at Lewes District Council, adds: “It’s fantastic to see work taking place on this project which will not only enhance biodiversity, help with flood management and carbon storage but also allow the stream to flow unimpeded, unpolluted and with its native plants and wildlife protected. I know I’m not alone in hoping that we might be able to tempt back the internationally rare Ramshorn Snail into the new habitat created.”

Meanwhile, the Cuckmere River has recently won a share of major funding from Natural England to accelerate nature recovery. Around 12,000 hectares of land from Seaford to Eastbourne, in East Sussex, will benefit from government funding for biodiversity restoration. Watch this space!

Challenges and solutions

There’s lots of positive stories about rivers, but the statistics are stark and show how much work needs to be done. Over 85 per cent of England’s rivers remain in a poor ecological condition and every single one fails to meet chemical standards, according to The Rivers Trust.

That has serious implications for both us and wildlife and is, ultimately, unsustainable.

Pollution from sewage discharges, intensive agriculture, and road run-off continues to harm our rivers and the chances of wildlife being able to bounce back.

So, what’s the solution?

The National Park has limited powers with regards to river pollution, but what we can do is be champions and national advocates for our rivers, working proactively with Government, councils, landowners, water companies, agencies and charities to improve river health. The truth is that no single organisation can reverse the national decline, but partners coming together with the right resourcing and vision can start to make a real difference.

Some solutions could be:

Significantly reducing wastewater discharges into our rivers and ensuring that water companies are incentivised to reduce pollution.
A strong planning system to ensure that new development does not exacerbate river pollution, as well as new biodiversity net gain schemes that improve river health. This is where the National Park Authority can make a real difference as a Local Planning Authority with nature recovery and climate action as top priorities. Protecting water is a key element of the South Downs Local Plan, including measures such as water efficiency and sustainable drainage. Our Partnership Management Plan also prioritises water.
Soil is central to river restoration! Over the last 50 years there has been a national decline in soil health leading, locally, to erosion and increased sediment and pesticides in our rivers. We need to work with landowners to help reduce soil erosion, improve carbon capture and help reconnect wetlands. Ultimately, the health of the land around a river is as important as the water itself.
Working with farmers and landowners to ensure more river-friendly farming. Some of this work has already been started by The Aquifer Partnership, which is focused on protecting groundwater rather than rivers, but the two are not mutually exclusive. Work to reduce nitrogen leaching and regenerative grazing, where livestock are allowed to graze more intensively for shorter periods, will ultimately benefit groundwater and freshwater ecosystems. The use of winter cover crops can reduce nitrate leaching by a staggering 90 per cent.
Further reducing non-native invasive species such as the Himalayan Balsam and Japanese Knotweed. The National Park’s ranger teams and volunteers carry out some clearance work to help this, but more could be done nationwide at a community level.
Promoting custodianship of rivers – simply by everyone caring, it could encourage further good work in the future on this wave of positivity.
Further funding opportunities from the public and private sector to support new river restoration projects such as the ones at Cockshut and Cuckmere.

It’s never going to be an overnight change. The Ouse and Adur and all their tributaries, for instance, flow through over 2,000 landholdings, so the key to success is going to be partnership working on a mass scale.

What you can do

Community action has a big part to play. There are a number of community groups that are focused on helping our rivers. One very inspiring group is “Love Our Ouse”, an exciting community-based initiative to link people to celebrate, raise the profile of and upscale positive action for the Ouse from source to sea.

Love our Ouse is about being inclusive and connecting all sorts of people; residents, community groups, recreational users, landowners, farmers and everything in between! Why not get involved?! Check out https://loveourouse.org to find out more.

There are a number of brilliant charities and groups working to help protect and enhance rivers and they often have volunteering opportunities and local events. Here’s just a few of them:

Why not volunteer for the National Park? There are a number of formal volunteering roles where you can learn practical conservation skills from rangers and see what conservation in action is like in the landscape.

Restoring the rivers of the South Downs National Park – what’s been done and what we need to do