Rivers at Risk: a call to protect national park freshwaters
26th September 2025
A timely report led by the Campaign for National Parks in partnership with the Rivers Trust underlines why we need to protect the best remaining freshwaters, says Freshwater Habitats Trust Technical Director Dr Naomi Ewald.
More than half of the rivers in our national parks are failing. That was the stark message in the National Parks Rivers at Risk Report, published last week.
The report warns of the declining state of freshwaters in our most iconic landscapes, revealing that 57% of rivers in national parks are classed as moderate, poor, or bad ecologically. It points to several pressures behind this alarming figure, including combined sewage overflows occurring twice as often in national parks as elsewhere.
Published ahead of the much-anticipated Water Reform Bill, Rivers at Risk serves as a plea to Government to ensure our national parks’ rivers and other freshwater habitats are properly protected by legislation.
The report underlines what our research and practical work has shown: we need to prioritise protecting the highest quality places for freshwater. It also highlights the urgency and relevance of our new work to investigate the benefits of upgrading small sewage treatment plants, which typically serve our national parks.
Protecting the best: building the Freshwater Network
Protecting the best remaining freshwater habitats is a simple, but radical, concept. And it’s the principle that we’ve put at the heart of the Freshwater Network for two reasons:
- If we don’t protect those last strongholds where rare and threatened wildlife is still holding on, we risk losing species forever.
- These high-quality sites are the foundation for broader ecological recovery. By building out from the best places, we can reconnect habitats and landscapes.
As a freshwater ecologist working in the New Forest – a place that I care about deeply – I was struck to see the report highlighting threats to the River Lymington, which runs through the New Forest National Park.
- Lymington River, New Forest National Park. (c) Katharina Brandt/Alamy
With its pristine ponds, wetlands and streams, the New Forest is an internationally significant place for freshwater wildlife. Many of the rare species that live here are extinct almost everywhere else. That’s why it is now classed as an Important Freshwater Area.
As co-hosts of the New Forest Catchment Partnership with the New Forest National Park Authority, we work together with other partners, local communities, and landowners, to protect and restore these habitats and the amazing plants and animals they support.
Our collaborative work in the New Forest focuses on safeguarding the best remaining habitats by promoting sustainable tourism, for example, and working with local businesses. Alongside this, we are building out from high-quality sites by creating and restoring waterbodies around the edge of the Forest.
Upgrading small sewage treatment works
The report presents the Lymington as a ‘river at risk’, polluted by 9,737 hours of sewage spills in 2024 alone. A key recommendation of the report is for sewage treatment works in national parks to be upgraded so these special places can be better protected.
This is an issue we’re tackling through pioneering new research. Our New Forest Area Lead, Gemma Stride, is undertaking a PhD study with Bournemouth University and Southern Water to investigate whether or not implementing measures at larger water treatment works will actually make a difference to special places like the New Forest.
There is now pressure on Government and the water sector to upgrade water treatment works. However, investment to date has focused on larger treatment works in the biggest rivers.
- Woodfidley Passage - mixed woodland, wetlands and heathland near Beaulieu Road Station, New Forest National Park. (c) Will Perrett/Alamy
Sewage treatment works serving fewer than 2,000 people are not legally required to use ‘secondary treatment’, which removes organic matter. That means that these smaller treatment works, which are typically in rural areas, only provide basic water treatment – making our national parks more vulnerable to pollution.
Although the average volume of sewage pollution in headwater streams is lower than in downstream rivers, it can cause more damage. This is because headwater streams are small, so sewage can make up a larger proportion of the waterway’s volume. Our work with the water industry through Headstart will include addressing the impact of sewage by upgrading small treatment works.
The Rivers at Risk report should act as a wake-up call to Government. It also points to some of the solutions. Now we need stronger regulations and targeted investment to reset the water environment and reverse the decline of freshwater biodiversity in some of our most loved landscapes.