Resilient European Cities: Nature-Based Solutions for Clean Water

What nature-based solutions can best tackle diffuse pollution from agriculture?

Nature-based solutions for source water protection modelled in the report

Key Findings:

To help prioritize and mobilize NbS investments in Europe, the report models the impact of nutrient and sediment pollution for 109 European cities that are significantly reliant on surface water sources for their drinking water supplies and are particularly exposed to diffuse pollution due to significantly altered landscapes. These cities are home to 78.5 million people—equivalent to 15 percent of the population of the European Union and the United Kingdom combined.

• Of the four NbS reviewed, planting cover crops has the greatest potential to mitigate sediment and nutrient pollution for the largest number of selected cities.
• Forest protection could also be an important approach for reducing or avoiding soil loss and protecting water quality for many of the identified cities.
• While more limited in their potential to mitigate pollution as individual strategies, riparian buffers and reforestation can still play an important role in protecting source catchments.
  
  

Comparison of NbS potential across different NbS and pollutant types 

• At least 63 European cities, home to 42 million people, could significantly benefit from investment in NbS at scale. The cities that most stand to benefit are shown on the maps below.
  
  

Nature-Based Solutions Potential to address phosphorus for selected cities
(all NBS combined)

Recommendations

In order for NbS to deliver maximum impact on water security in Europe, a number of strategic steps must be taken. First, NbS must be implemented at scale—a piecemeal approach is unlikely to have much impact. Second, it’s important to prioritize those areas where nature can provide the greatest impact in order to demonstrate proof of concept and mobilize funding. Third, more localized collective action mechanisms should be established to coordinate stakeholders across sectors and accelerate the implementation of NbS. Existing governing mechanisms, like River Basin Districts, are in place throughout the European Union but are not set up to tackle specific challenges and implement coordinated actions at a more local level. And finally, it’s important that these efforts operate with clear targets and are designed to monitor outcomes—this is crucial for adjusting strategies, and for demonstrating effectiveness and driving further buy in.

Looking Forward: Accelerating the adoption of nature-based solutions in Europe

The Nature Conservancy is fortunate to have the support of visionary people and organizations, whose generosity allows us to pursue our mission. We are grateful to the Enterprise Rent-A-Car Foundation for supporting our work to find water solutions that work for rivers and the communities that depend on them.