Site: With ~1.4 million inhabitants, Lyon Metropole is the 3rd biggest metropolis in France.

Situation: Lyon is classified to have a semi-continental climate zone, but climate change has shifted it closer to a Mediterranean climate.  The area suffers from increasing heat waves, stronger storms and occasional flooding, especially in summer. During those events, the existing sewer system cannot handle the rainwater quantities, creating combined sewer overflows.

Solution: These conditions allow to test and assess NICE nature-based solution hybrid subsurface wetlands for stormwater and combined sewer overflow treatment in the Lyon Metropolis urban area. One pilot to treat 5 m3/d of stormwater and combined sewer overflow is implemented. The pilot entails two systems of 20m², that will be built to test/implement standalone experiments, or in combination three optimisation paths:

  • Using light intensification through the installation of a forced aeration system to degrade more recalcitrant pollutants (micropollutants)
  • Using reactive materials to absorb/adsorb micropollutants (incl. heavy metals)
  • Using bioaugmentation to “boost” pollutant/micropollutant degradation/inactivation

The research done in the Lyon 'Urban Real Lab' will be utilised to implement the solution in other project cities.

An example of a sewer overflow system  in Marcy l’étoile (Lyon Metropolis), credit: EcoBIRD/Syntea

INRAE example of a test site for hybrid subsurface wetlands (Lyon Metropolis). Credit: INRAE, Lyon Metropolis and EcoBIRD/Syntea

The NICE Urban Real Labs are ideal test beds for nature-based solutions for circular urban water solutions, as they have varied geographical, environmental and socioeconomic characteristics.

The Urban Real Labs cover a wide range of climate zones: tropical and subtropical (Pereira and Turin), Mediterranean (Talavera, Algeciras, Benalmádena, Lyon, Cairo), transition climate with extreme temperatures (Madrid), oceanic (Vigo, Aarhus), and Baltic (Gdansk).


European Union

This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No.101003765.