Why we need to treat freshwaters as a network
16th December 2025
It’s time to stop thinking about waterbodies in isolation and start focusing on whole freshwater landscapes, says Freshwater Habitats Trust CEO Professor Jeremy Biggs.
When we talk about freshwater conservation, it’s natural to picture a healthy river, a pristine pond, or a thriving wetland. That’s exactly how most people have traditionally approached protecting freshwater life – focusing on single habitats as if they exist in isolation.
But wildlife doesn’t see the world that way. If we’re serious about reversing the decline in freshwater biodiversity, we need to fundamentally change how we think about – and protect – our freshwater environment.
Shifting our approach towards whole freshwater landscapes means treating habitats as interconnected and interdependent. And that’s exactly the approach we’re taking with our partners as we build the Freshwater Network.
- Coleshill fen at the National Trust Coleshill estate.
The problem with focusing on single habitats
Historically, freshwater conservation has been fragmented. Individual larger waterbodies, such as rivers and lakes, have received the most attention from scientists and policymakers. Meanwhile, the vast network of smaller freshwaters – the ponds, headwater streams, ditches, and wetlands that make up about 80% of our freshwater environment – have been consistently overlooked and undervalued.
This reflects a fundamental misunderstanding of how freshwater ecosystems work. Research has shown that around two-thirds of freshwater species use different waterbody types – not just rivers or ponds or lakes or wetlands.
For example, a dragonfly might start its life as larva in a pond but then hunt as an adult across wetlands. Atlantic Salmon and Sea Trout make use of healthy, unpolluted headwaters and upper reaches of rivers for spawning, before the adult fish migrate downstream to the sea. The European Eel, which undertakes one of the most epic migrations of any species, lives out its juvenile years in rivers, ponds, lakes, streams, ditches, and estuaries before travelling back across the Atlantic to the Sargasso Sea as adults to breed.
And, of course, most freshwater plants grow in and around a wide range of standing and running waters, and there’s more and more evidence that their persistence depends on that varied network of freshwater habitats.
Even those species that depend on a specific habitat type can benefit from having access to a wider network. For example, our work with the Newt Conservation Partnership to expand habitats for Great Crested Newt shows that creating networks of new clean water ponds in areas where this protected amphibian is already breeding allows populations to spread out into the landscape. The latest monitoring results show that Great Crested Newts have now colonised 90% of mature sites where ponds have been created.
The reality is that freshwater life depends on networks of habitats, not isolated fragments.
What the evidence tells us
For the most compelling scientific case for treating freshwaters as networks, we need to look to the US. Many of the most significant research findings are presented in a landmark study by the US Environmental Protection Agency demonstrating why we must think about freshwater landscapes as integrated systems. Bringing together more than 40 years of evidence, the research demonstrates the chemical, physical, and biological connectivity of streams and wetlands. It describes the connection between wetlands and running waters, and explains how species move between streams, wetlands and other waterbodies.
The study demonstrates that headwater streams not only supply most of the water in our rivers but also transport sediment that shapes river channels. These small running waters also carry organic matter, and nutrients – as well as countless organisms – through different tributaries and river systems.
- Freshwater Habitats Trust CEO Professor Jeremy Biggs surveying a pond at the Waddesdon estate. Photo: Jill Mead.
This study played a critical role in expanding protections put in place under the Clean Water Act. Sadly, this forward-thinking approach to freshwater management and conservation has been compromised by recent changes to the implementation of the Act that would reduce protections for small waterbodies.
Practical steps to protect and restore freshwater landscapes
At Freshwater Habitats Trust, we’re putting a network approach into action through projects across England and Wales.
As co-hosts of several catchment partnerships, we’re bringing together landowners, farmers, local communities, and conservation organisations to protect and restore freshwaters at a landscape scale. These partnerships recognise that effective conservation requires joined-up action across whole catchments, not just individual sites.
Through the New Forest Catchment Partnership, we’re working with the National Park Authority, Environment Agency, Natural England, and local landowners to protect one of the UK’s best remaining freshwater networks. Here, ancient bogs, valley mires, and ephemeral pools form an interconnected system supporting rare species like Coral Necklace, Fairy Shrimp, and Pillwort. Our collaborative work in this internationally significant freshwater landscape focuses on maintaining water quality across the whole of this network of habitats.
In mid-Wales, our River Irfon Catchment Project takes a whole-catchment approach to reversing the decline in freshwater biodiversity. This includes the threatened Freshwater Pearl Mussel, which relies in pristine river water. We’re working with farmers, land managers, and local communities to reduce diffuse pollution, restore habitats, and improve connectivity between different waterbody types. And as well as taking steps to improve water quality in the River Irfon, we’re extending the network of freshwater habitats, by creating ponds on the floodplain and bringing back grazing to degraded fens and wet grasslands.
Our long-standing Water Friendly Farming project in Leicestershire has demonstrated how networks of small habitats can increase biodiversity at a landscape scale. By creating strategically placed clean water ponds on agricultural land, we’ve increased wetland plant biodiversity across the landscape by 16%, with a notable increase in threatened species.
- A freshwater landscape in the Irfon catchment - Jason Elberts
And we’ve achieved similar results around Pitsford reservoir in Northamptonshire, where we’ve worked with Anglian Water and local landowners to create new clean water ponds, increasing wetland plant diversity by nearly 20% (71 to 84 different species) across the site’s ponds, streams and ditches.
At the Coleshill estate on the Oxfordshire-Wiltshire border, we’re restoring an historic floodplain wetland mosaic with the National Trust. We’ve created a network of interconnected wetlands, streams, and wet grassland that will support a rich diversity of freshwater species while also storing floodwater and filtering nutrients.
An opportunity for policy to catch up
Despite the weight of scientific evidence and practical success stories, the policy framework has not yet embraced a network approach to freshwater protection. Current legislation still largely focuses on individual waterbodies – primarily rivers – often missing the critical connectivity between different habitat types.
The forthcoming Water Reform Bill represents a golden opportunity to secure tangible improvements for freshwater biodiversity by properly recognising the whole freshwater environment. We’re calling on Government to use this moment to shift legislation towards thinking about the whole water environment, particularly by properly monitoring and protecting small waters.
Local Nature Recovery Strategies offer another important mechanism for adopting a network approach. Our guidance for local authorities emphasises the critical importance of including the whole freshwater environment in these plans – all the ponds, streams, ditches, and wetlands that collectively support freshwater biodiversity.
The advantage of a network approach
Why does thinking about freshwaters as networks matter so much?
A network approach means we value small waters alongside large ones. It means we protect not just individual sites but the connections between them.
It also means we can be more strategic and efficient. By understanding how different parts of the freshwater network interact, we can target interventions where they’ll have the greatest benefit. Restoring a headwater stream could improve water quality for miles downstream. A wetland complex might reduce flooding across an entire catchment. A network of clean water ponds can support populations of rare species that could never survive in isolated fragments.
With freshwater species declining faster than any other group, the scale of the freshwater crisis can feel overwhelming. But if we start focusing on landscapes rather than isolated sites, we can see opportunities for recovery.
- New Forest in Winter - Gemma Stride
Building the Freshwater Network
A key component of our strategy to build the Freshwater Network is to protect and build out from Important Freshwater Landscapes. With our partners, we’ve identified 24 Important Freshwater Landscapes across England and Wales where we can safeguard the best remaining habitats and reconnect biodiversity hotspots.
These landscapes cover more than a third (36%) of England and Wales and represent a significant opportunity for us to create a network for freshwater wildlife. Within each of them, there are many high-quality habitats, such as fens, ponds, and rivers. But it is the combination of these individual waters that makes these places so special.
We have seen how freshwater plants and animals can thrive across a landscape – from the ponds, mires, and headwater streams of the New Forest and Dorset Heaths to the upland flushes, valley mires, and blanket bogs of the Cheviot Hills on the Scottish borders. This gives us hope that, by taking a network approach to freshwater conservation, we can halt and reverse the decline of freshwater biodiversity.