Nature-Based Solutions for stormwater management: A case study with Multi-Hydro in Parc Molière, France

Over the last few decades, the urban hydrological cycle has undergone significant changes due to the influence of the built environment, resulting in rapid runoff and increased risk of flooding. Faced with these challenges, nature-based solutions (NBS) are emerging as an appropriate response, especially in densely populated areas, facing the impacts of climate change and biodiversity loss. The application of green infrastructures, as evidenced by Parc Molière in Les Mureaux, France, with its 700 trees, 11,500 m² of flowerbeds, 8,700 m² of grassland and 5,000 m² of gardens, represents a sustainable approach to urban stormwater management. By reintroducing extensive impermeable areas to the open air, Parc Molière strengthens biodiversity, facilitates animal movement, promotes air cooling and reduces urban heat islands, while also modifying hydrological behavior. Carried out in the framework of the LIFE ARTISAN project, this study uses the Multi-Hydro software, developed at the École des Ponts ParisTech, to computationally model the Parc Molière area in two different scenarios: before and after the creation of the green spaces. Based on a fully distributed and physical hydrological model, Multi-Hydro is able to illustrate the influence of NBS by comparing the obtained simulations with instrumented hydrological data. The results should demonstrate that the NBS have a significant impact on peak flow and total runoff volume, mitigating the negative effects in an urban hydrological scenario.