Europe’s approach to flood protection is increasingly looking beyond concrete barriers, drainage systems and engineered river defences.
As extreme rainfall places growing pressure on communities and infrastructure, restoring natural landscapes is emerging as an important part of the continent’s efforts to manage flood risk.
From reconnecting rivers with their floodplains to restoring wetlands and improving soil health, nature-based solutions offer ways to slow water movement, create additional storage capacity, and reduce pressure on vulnerable catchments.
Rather than attempting to control every river and redirect every drop of rainfall, these approaches work with natural processes to help landscapes absorb and manage excess water. They can also deliver wider environmental benefits, including improved biodiversity, healthier ecosystems and greater resilience to drought.
However, while nature-based solutions are gaining recognition across European flood management strategies, their effectiveness depends on where and how they are implemented. They are not a universal replacement for conventional flood defences, but could play an increasingly important role alongside them.
What are nature-based solutions?
Nature-based solutions are interventions that protect, restore or sustainably manage natural ecosystems to address environmental and societal challenges.
In flood management, they involve using the natural ability of landscapes to absorb, retain, slow or redirect water. This can include restoring wetlands, allowing rivers to reconnect with their floodplains, planting trees, improving agricultural soil management and introducing more green space into urban environments.
The underlying principle is relatively straightforward: healthy ecosystems can help regulate the movement of water through the landscape.
For example, wetlands act as natural storage areas, temporarily holding excess rainfall and river water. Vegetation and healthy soils can improve water infiltration, reducing the volume and speed of surface runoff. Meanwhile, restored floodplains provide rivers with additional space to expand during periods of high water.
These interventions can also provide benefits beyond flood prevention. Wetland restoration can support wildlife habitats, while woodland creation and improved soil management can contribute to carbon storage, erosion control and better water quality.
Restoring wetlands and floodplains to create natural water storage
One of the most significant applications of nature-based solutions is restoring wetlands and natural floodplains.
Wetlands, including marshes, peatlands and reedbeds, can hold substantial quantities of water, helping to regulate river flows and reduce the speed at which rainfall reaches waterways. During periods of heavy precipitation, these landscapes provide additional storage capacity, potentially reducing the volume of water moving downstream at the same time.
Floodplains perform a similar function. Historically, many European rivers have been straightened, narrowed or separated from surrounding land by embankments to support agriculture, urban development and transport infrastructure.
Although these interventions have helped control rivers in certain locations, they have also removed natural areas where excess water could previously spread and be stored.
Reconnecting rivers with their floodplains can help reverse this process. By removing or relocating selected embankments and restoring natural channels, floodwater can be allowed to spread into designated areas during periods of high flow.
This can slow the movement of water, reduce or delay flood peaks and provide additional protection for communities further downstream.
However, the effectiveness of these measures depends on local geography, river characteristics and the scale of restoration. Floodplain restoration can reduce or delay flood peaks, but outcomes are highly site-specific and require careful assessment.
Slowing the flow through healthier landscapes
Nature-based flood management is not limited to major river restoration projects. Smaller interventions across entire catchments can also help reduce the speed and volume of water entering rivers.
Woodland creation, hedgerow planting, improved soil management and the installation of natural barriers are among the approaches being explored.
Trees and vegetation can intercept rainfall, while their root systems help maintain soil structure and improve infiltration. Healthy soils with greater organic matter content can also retain more water, reducing the amount of rainfall that immediately becomes surface runoff.
In agricultural areas, practices such as reducing soil compaction, maintaining vegetation cover and planting cover crops can help improve water retention and limit erosion.
Another approach involves installing so-called leaky dams, which use natural materials such as timber to partially obstruct small streams and drainage channels. Rather than completely blocking water, these structures allow it to pass through while temporarily holding back some of the flow during heavy rainfall.
Individually, these measures may have relatively limited effects. However, when implemented across a catchment, they can contribute to a wider natural flood management strategy.
How European projects are putting nature-based solutions into practice
Several European initiatives demonstrate how restoring natural processes can form part of wider flood protection strategies.
The Netherlands: Making room for the River Waal
The Netherlands provides an established example through its Room for the River programme, which sought to reduce flood risks by giving major rivers more space to accommodate high water levels.
One prominent project took place in Nijmegen, where the River Waal had become particularly vulnerable to flooding because of a narrow section of the river channel.
Following major floods in 1993 and 1995, the city introduced a project to increase the river’s capacity. Work began in 2012, involving the relocation of an existing dyke 350 metres inland and the construction of a new channel alongside the original river.
Completed in 2016, the project achieved a 35cm reduction in river water levels, exceeding its original 27cm target. During periods of high flow, approximately one-third of the river’s water can pass through the additional channel.
Importantly, the project also created a new river island that provides recreational space and supports natural habitats.
The initiative demonstrates how flood protection, urban development and environmental restoration can be incorporated into the same project.
Spain: Restoring the River Ebro
In Spain, the LIFE EBRO RESILIENCE P1 project is applying similar principles to the River Ebro, where flooding has caused significant damage to agricultural land, livestock, infrastructure and communities.
The six-year initiative focuses on improving the river’s natural structure and ecology while strengthening the ability of local communities to manage flood risks.
Its planned interventions include removing 1,800 metres of existing levees, reconnecting two river meanders and creating two high-water channels to help accommodate excess water.
The project also aims to restore 60 hectares of riverbanks, increase the number of habitats by 15% and protect three regional species at risk.
Alongside physical restoration, the initiative involves local communities through training, information-sharing workshops and collaborative working groups.
The project estimates its approach could reduce expenditure on flood risk mitigation measures by 40% and flood damage costs by 50% over ten years. These are project estimates rather than independently established outcomes.
Germany: Revitalising the Emscher Valley
Germany’s Emscher Valley provides another example of how nature-based solutions can be incorporated into heavily urbanised and industrialised landscapes.
For more than a century, the Emscher River in the Ruhr region was used as an open wastewater channel. Its natural characteristics were significantly altered to accommodate industrial development and drainage requirements.
A large-scale restoration programme began in the 1990s, gradually transforming an 85-kilometre stretch of the river.
Wastewater was redirected into underground sewer systems, allowing the river and its tributaries to be restored into more natural waterways.
The wider project has introduced green spaces, flood control areas, recreational environments and connected habitats throughout the valley.
The restoration is helping improve the region’s capacity to manage heavy rainfall, while also supporting biodiversity, cooling urban areas and improving water retention during dry periods.
Bringing nature back into Europe’s cities
While restoring rivers and wetlands is important for managing large-scale flood risks, cities face a different challenge.
Urban environments often contain extensive areas of concrete, asphalt and other impermeable surfaces. When heavy rainfall occurs, water cannot easily soak into the ground and instead flows rapidly into drainage networks, increasing the risk of surface water flooding.
Nature-based solutions can help address this problem by introducing more opportunities for water to be absorbed and temporarily stored within the built environment.
Green roofs and walls, urban forests, rain gardens, permeable pavements and sustainable drainage systems can all contribute to managing rainfall.
For example, rain gardens use vegetation and specially designed soil systems to capture and filter surface water, while permeable paving allows rainfall to pass through surfaces rather than immediately running into drains.
Urban wetlands and green spaces can also provide temporary storage during periods of intense rainfall.
These interventions are particularly relevant as European cities face increasing pressure from extreme weather and growing urban populations.
Incorporating natural features into urban planning can therefore help make cities more resilient to flooding, while creating greener and healthier environments for residents.
The role of EU policy in supporting nature restoration
Nature-based solutions are also becoming more prominent within Europe’s wider environmental and climate adaptation policies.
A particularly important development is the EU Nature Restoration Regulation, which entered into force in August 2024.
The legislation establishes legally binding targets for restoring degraded ecosystems across EU Member States, including wetlands, forests, grasslands, rivers and lakes.
Its overarching objective is to introduce restoration measures covering at least 20% of EU land and sea areas by 2030, with the longer-term ambition of restoring all ecosystems in need of recovery by 2050.
The regulation recognises the role that healthy ecosystems can play in protecting communities against natural disasters, including flooding. Restoring wetlands and river systems can therefore contribute to both biodiversity recovery and climate resilience.
Alongside this, the European Commission’s wider water management strategy increasingly promotes working with natural processes to address the challenges of too much and too little water.
These policies reflect a broader recognition that flood management cannot rely exclusively on engineered infrastructure and emergency responses. Protecting and restoring natural water systems is also an important part of preparing for future climate risks.
The limitations of nature-based flood protection
Despite their potential, nature-based solutions are not a straightforward replacement for conventional flood defences.
Their effectiveness depends heavily on local conditions, including soil characteristics, topography, vegetation, river behaviour and the amount of land available for restoration.
For example, reconnecting a floodplain may provide substantial additional storage in one catchment but have a more limited effect in another. Similarly, woodland planting and soil improvements can reduce surface runoff, but their ability to manage exceptionally severe rainfall events is constrained.
There are also practical challenges associated with land ownership, agricultural interests, urban development and the cost of restoring degraded ecosystems.
Some interventions require significant space, while others take years to deliver their full benefits. Long-term maintenance and monitoring are also necessary to ensure that restored landscapes continue to function as intended.
Consequently, the most effective approach is likely to involve combining natural and engineered flood protection.
Traditional flood barriers, drainage systems and other infrastructure will remain necessary in locations where communities and critical assets face significant risks. However, incorporating wetlands, restored floodplains and natural water storage can help reduce pressure on these systems.
Can working with nature make Europe more flood-resilient?
Nature-based solutions offer an important additional dimension to Europe’s response to increasing flood risks.
By restoring wetlands, reconnecting rivers with floodplains, improving soil health and introducing green infrastructure into cities, European countries can make better use of natural processes to manage excess water.
The examples emerging across the continent demonstrate that these approaches can deliver more than flood protection alone. They can also support biodiversity, improve water quality, create recreational spaces and strengthen resilience to other climate-related challenges, including drought and extreme heat.
However, their success will depend on sustained investment, effective planning and a willingness to consider flood management at the scale of entire landscapes and river catchments.
As Europe continues to adapt to a changing climate, nature-based solutions are likely to become an increasingly important part of the overall strategy. Rather than attempting to keep water away from every vulnerable area, the challenge is increasingly about creating landscapes and communities that can accommodate it more safely.
