France is increasingly implementing vegetated swales, known as 'noues,' as a sustainable approach to manage urban stormwater and promote biodiversity. These landscape features offer an ecological solution to mitigate flood risks and enhance water quality in urban environments.
Different types of swales, including infiltration, buffer, and mixed swales, are adapted to suit various soil conditions and urban planning requirements. These swales effectively reduce the volume of water directed to traditional sewage systems, contributing to significant cost savings in stormwater management.
Nantes has reported a 25% reduction in stormwater management costs due to the implementation of swales in residential areas. These swales also reduce the volume of water directed to traditional sewage systems by 30-40%. The integration of native plants fosters micro-habitats for pollinators and small mammals, thereby enhancing floristic diversity. Cities like Bordeaux are incorporating swales into public parks, creating multifunctional ecological zones that attract diverse fauna and naturally slow down rainwater runoff. Regular maintenance, including mowing and debris removal, ensures the long-term effectiveness of these systems. Studies indicate that swales can reduce up to 80% of pollutants in stormwater and lower local temperatures during heatwaves.