What works in freshwater restoration? New research charts the course of successful projects – and exposes a farm policy gap

Europe’s rivers and wetlands are woven into the continent’s identity and economy. They supply drinking water, sustain agriculture, buffer floods and harbour a disproportionate share of its biodiversity. Yet they are also among its most damaged ecosystems, shaped by decades of drainage, river straightening, pollution and intensifying land use.

Two new publications offer a revealing snapshot of where Europe’s freshwaters are headed. One distils lessons from 18 real-world restoration projects across the continent, asking what it would take to scale up Nature-based Solutions from scattered pilots to systemic change. The other examines whether the EU’s €307bn agricultural subsidy programme is doing enough to support that ambition.

Together, they tell a story of growing practical know-how alongside a stubborn policy misalignment.

From isolated projects to continental-scale change

The first publication draws on experience from 18 demonstration cases implemented under the MERLIN project, an EU-funded initiative focused on restoring freshwater ecosystems through Nature-based Solutions. Its aim was not to evaluate ecological outcomes alone, but to understand the conditions that make restoration efforts scalable and lasting.

What emerges is less a technical manual than a framework for change. The authors identify five interlocking ‘building blocks’ that consistently underpin successful restoration.

The starting point, they argue, is a thorough review of ecological status and pressures. Projects that invested from the outset in understanding hydrology, land use and socio-economic drivers were better placed to address root causes rather than symptoms. A wetland cannot simply be reflooded if upstream drainage systems remain untouched.

But science alone is not enough. Equally important is what the authors call creating ‘narratives of the future’: shared, locally-grounded visions of what a restored landscape should look like and why it matters. In practice, this means bringing farmers, local authorities, water managers and communities into a common conversation. Where such narratives were absent, MERLIN researchers found that projects struggled to build momentum.

The publication also stresses the importance of adaptive, evidence-informed management. Freshwater systems are dynamic, and restoration projects rarely unfold neatly. The most effective ones embraced monitoring and learning, adjusting their approaches in response to new data rather than adhering rigidly to original plans.

Long-term financing proved another decisive factor. Restoration timelines often outlast political cycles and short-term funding schemes. Successful initiatives tended to blend public and private resources and think strategically about sustaining investment beyond the life of a single project.

Underpinning all of this is stakeholder engagement. Projects that treated participation as a central pillar – rather than a box-ticking exercise – were more likely to endure. Successful restoration, the MERLIN researchers suggest, is as much about governance and trust as it is about hydrology and habitat.

Crucially, none of this hinges on novel technology. Instead, it points to the importance of integration: aligning ecological science, community engagement and financial planning within complex social-ecological systems.

The CAP conundrum

If the first MERLIN publication offers a roadmap for scaling restoration, the second examines whether one of Europe’s most influential land-use policies is equipped to support it.

The EU’s Common Agricultural Policy will direct €307bn to agriculture and rural areas between 2023 and 2027. Given that farming practices – particularly drainage, river modification and nutrient runoff – are among the main drivers of freshwater degradation, the CAP should in theory be a central lever for change.

The reality, the authors find, is patchier than that.

Analysing CAP Strategic Plans submitted by EU member states, the MERLIN researchers map how different funding instruments relate to freshwater restoration. These instruments range from baseline environmental ‘conditionality’ rules and voluntary eco-schemes to rural development measures and investment funding.

While examples of good practice exist, interventions directly targeting key freshwater pressures remain limited in scope. Measures to reduce the impacts of agricultural drainage, restore wetland and floodplain connectivity, and increase water retention at landscape scale are present in many plans, but often peripheral. In many cases, they are add-ons rather than priorities.

The result is a patchwork. Some countries have embraced more ambitious water-focused schemes; others have taken a cautious approach. Overall, the authors conclude, successive CAP reforms have been incremental – and well short of transformative – on environmental objectives.

Ambition meets reality

Both publications sit within the wider context of the EU’s environmental agenda, including the European Green Deal and the Nature Restoration Regulation, which set bold targets for recovering degraded rivers, wetlands and floodplains.

Yet the research points to a persistent gap between ambition and delivery.

On the ground, restoration practitioners are learning how to work across sectors, manage ecosystems adaptively and build local support. They are working out what it takes to embed Nature-based Solutions within complicated, working landscapes. But a key financial engine shaping those landscapes – agricultural subsidies – is not consistently pulling in the same direction.

The knowledge needed to restore freshwater systems is growing, grounded in practical experience across diverse European contexts. The barrier to transformational change for Europe’s environments is thus less about ecological uncertainty than about policy coherence.

A pivotal moment for European freshwaters

With the current CAP period running to 2027 and debate on future reforms already under way, the MERLIN publications arrive at a critical juncture. They suggest that if Europe is serious about its restoration commitments, water-focused measures will need to move from the margins of agricultural policy to its mainstream.

That could mean stronger incentives for rewetting drained land, support for floodplain reconnection, and making landscape-scale water retention a core strategy rather than a niche option.

Freshwater ecosystems tend to remain out of sight until crises like droughts, floods or collapsing species populations strike. Yet they underpin both environmental resilience and human wellbeing.

The message from this new research is sobering but not defeatist. Europe has both the scientific understanding and the practical experience to restore its rivers, streams, peatlands and wetlands. What it needs now is for policy and funding to catch up with what practitioners on the ground already know.

Read the open-access articles in full

Birk S, et al (2026) Building blocks for upscaling freshwater ecosystem restoration: Place-based strategies for a transdisciplinary challenge. In: Kaden US, et al (Eds) Wetlands in a Changing Climate: Restoring Coasts and Floodplains. Nature Conservation 62: 261-287. https://doi.org/10.3897/natureconservation.62.148938

Rouillard J, et al (2026) Does the Common Agricultural Policy 2023–2027 support the restoration of freshwater ecosystems? In: Kaden US, et al (Eds) Wetlands in a Changing Climate: Restoring Coasts and Floodplains. Nature Conservation 62: 337-354. https://doi.org/10.3897/natureconservation.62.148845

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This article is supported by the MERLIN project.