Freshwater ecosystems across Europe, including rivers, lakes, wetlands and floodplains, face increasing pressures from pollution, fragmentation, over-extraction and climate change, with most failing to meet ecological targets despite existing EU policy frameworks.

Methodological framework for the spatial prioritisation of restoration measures

This report presents a strategic, evidence-based approach to support the upscaling of freshwater restoration and the implementation of Nature-based Solutions across Europe. Central to the approach is the MERLIN Upscaling Workflow, a flexible decision-support tool that uses Europe-wide datasets to identify high-impact restoration areas.

Simulation of ecological and societal impacts at the European scale

The MERLIN Upscaling Workflow can be applied across Europe to simulate ecological and societal benefits of restoration initiatives and develop cost-effective implementation strategies. The workflow can be used by administrations, agencies and experts contributing to the development of restoration actions, for instance, under the Nature Restoration Regulation. It can also be used by authorities involved in nature conservation and river basin management to plan synergistic actions delivering on the Nature Directives and the EU Water Framework Directive. 

Quantification and monetary valuation of selected ecosystem services

The upscaling workflow has been applied in five selected case studies to demonstrate its applicability and usefulness in quantifying ecosystem service benefits and valuing these benefits through cost-benefit analysis, highlighting outcomes such as nutrient retention, flood risk mitigation and climate regulation.

Model-based assessment of ecosystem services and biodiversity restoration potential

Using data-driven modelling based on site conditions, land use, hydrology and connectivity, the restoration potential for freshwater habitats was estimated, focusing specifically on lake and stream habitats within Natura 2000 sites. 

The report also explores funding pathways, emphasising more effective use of EU instruments, national schemes and private finance.

Financing pathways and diversified funding strategies for restoration

Achieving restoration at scale requires not only identifying the most promising locations for intervention but also ensuring that projects are financially viable. The MERLIN Upscaling Workflow therefore includes a dedicated component on financial planning that helps restoration teams develop integrated financing strategies. This approach links ecological modelling, ecosystem service valuation and cost–benefit analysis to the identification of suitable funding and revenue streams.

Multi-objective optimisation across overlapping legal and policy frameworks

The report aims to support EU institutions and Member States in translating restoration commitments into operational actions and funding arrangements that deliver measurable ecological, economic and societal outcomes. We recommend the MERLIN Upscaling Workflow as an evidence-based tool to prioritise and scale up freshwater restoration across Europe. By identifying context-specific opportunities and quantifying ecosystem service benefits early in the planning and design process, the workflow enables strategic, cost-effective restoration at regional and local scales.

In light of the severity of the current biodiversity crisis, we recommend that restoration efforts aim to realise the full biodiversity potential of ecosystems. These efforts should explicitly address synergies and trade-offs where multiple policy objectives and legal protections intersect in order to ensure the effective conservation of threatened and protected species, habitats and ecosystems.