Rising waters | Rooted solutions
Governance, evidence and confidence in nature-based solutions
Nature-based solutions rely on shared decision-making, strong governance and evidence. Building trust, measuring outcomes and partnership working are key to delivering scalable, effective solutions.
Nature-based solutions (NbS) are widely supported as a means to achieve flood resilience, climate adaptation and biodiversity recovery. However, delivery often depends on how decisions are made about who benefits, who pays, and who carries risk.
These are not purely technical questions. They shape who has agency in decision-making, and whether outcomes are fair, inclusive and sustainable.
Decisions are distributed across systems
One of the clearest lessons from Ousewem is that decisions about NbS are rarely made by a single organisation or actor. Instead, they are distributed across local authorities, regulators, researchers, land managers and communities.
This makes governance a central challenge. Progress depends first on trust, legitimacy and shared confidence across partners. Formal roles and responsibilities still matter, but they are shaped by how costs, benefits and risks are shared - and who has the agency to influence those decisions.
In practice, this requires participatory approaches to decision-making, where different interests are recognised and negotiated.
Evidence informs decisions, but does not determine them
Robust evidence is essential for nature-based solutions. In Ousewem, hydrological modelling, ecological data and catchment analysis help identify where interventions may reduce flood risk and deliver environmental benefits.
However, evidence alone does not resolve key questions about equity and decision-making - including how public and private benefits are balanced, how vulnerability and exposure to risk are taken into account, and who ultimately bears costs and responsibility. In practice, this often requires adapting how evidence is used in response to local context and priorities.
For this reason, evidence plays a critical role as decision support, rather than as a substitute for decision-making. Ensuring that those most affected have a voice in how solutions are designed and delivered is of critical importance, including in finding the balance between public and private funding sources.
As Sally Ashby, financial strategy lead for Ousewem, explains:
Strong evidence is essential, but it doesn’t make decisions for us. Questions about risk, responsibility and equity still need to be worked through with all partners. That’s why governance and trust are just as important as the data itself.
Ecological benefits are central to the value of NbS
While flood risk management and climate resilience are often a starting point, NbS also deliver significant ecological benefits, such as to the restoration of habitats, biodiversity and ecosystem functioning.
Across the SUNO catchment, evidence shows that these benefits vary by location and intervention type. Understanding this variation is essential for making informed, place-based decisions about where and how NbS are implemented.
Crucially, ecological outcomes are not an add-on. They are a core part of the long-term value, resilience and climate adaptation case for NbS.
Catherine Cowie, Research Fellow at the University of York, adds:
Ecological benefits are a fundamental advantage of using nature-based solutions, often highly valued in the cost-benefit analyses of interventions.
"However, there is variation in the quality and availability of evidence for these benefits for different NbS activities and local contexts. The Ousewem project is researching how these benefits are measured in order to propose enhanced data collection strategies that will generate a robust evidence base to support effective decision-making."
Measuring what matters builds confidence
Defining success is itself a governance decision. In Ousewem, partners are co-designing a ‘gold standard’ set of indicators that capture flood resilience, ecological outcomes and social benefits. The consistent measurement of these indicators across multiple projects will help to build confidence among decision-makers, funders and regulators, facilitating investment in natural flood management.
Defining success is itself a governance decision. In Ousewem, partners are co-designing a ‘gold standard’ set of indicators that capture flood resilience, ecological outcomes and social benefits. The consistent measurement of these indicators across multiple projects will help to build confidence among decision-makers, funders and regulators, facilitating investment in natural flood management. See how Ousewem is developing indicators to support better decision-making and investment:
Partnership enables delivery at catchment scale
Delivering NbS at scale depends on effective partnership working. This includes coordination across research, policy, land management and delivery organisations.
Land managers are a vital part of this system. Successful delivery relies on locally appropriate design, trusted relationships and ongoing support, enabling flood and ecological outcomes to be realised together.
From evidence to investment readiness
As interest in green finance and environmental investment grows, the link between evidence and funding becomes increasingly important.
Robust data, clear metrics and strong governance arrangements help create investment-ready NbS projects. At the same time, maintaining local accountability and equitable benefit-sharing remains essential.
This raises important questions about how public and private finance interact, and how funding models can support fair, locally appropriate outcomes.
Conditions for scaling nature-based solutions
Scaling NbS is not only a technical challenge — it is a question of governance and confidence.
From Ousewem’s experience, 4 conditions are critical, underpinned by collaborative working across partners:
- confidence
- capability
- consent
- continuity
Together, these provide the foundation for nature-based solutions that are not only evidence-led and scalable, but also equitable in how benefits, costs and decision-making are shared.
We’ll be exploring these themes further in our keynote presentation at the British Ecological Society Symposium, on 29 and 30 June 2026. If you’re attending - or would like to continue the conversation - we welcome the discussion.
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