Operational integration of soil engineering and nature-based solutions in urban environments: feedback from an engineering consultancy

In the face of increasing climate hazards and the growing complexity of urban environments, soils emerge as a key interface between water, vegetation, infrastructure and human uses. Their role goes far beyond that of a simple support: soils condition hydrological functioning, environmental quality, the adaptive capacity of developed spaces, and the long-term sustainability of projects. Yet, in many urban and peri-urban contexts, soils remain insufficiently integrated into design and management processes.This presentation will present feedback from scientists and engineers involved in urban development, regeneration and environmental management projects. Drawing on several concrete case studies, it illustrates how an integrated diagnostic approach to soils, water and land use can guide the design of more resilient projects, from the planning stage through to operational implementation.The examples cover a wide range of situations: the rehabilitation of degraded or contaminated soils, the creation of engineered soils from secondary materials, integrated stormwater management using vegetated systems, and the design of growing media capable of functioning sustainably under high urban constraints. These projects demonstrate how operational choices based on the physical, chemical and biological properties of soils can simultaneously address issues of water management, environmental quality and ecological functionality.Particular attention is given to the way these parameters are translated into operational design criteria: infiltration and storage targets, the ability of soils to filter or immobilize contaminants, their capacity to support diverse vegetation, and their compatibility with structural and use-related constraints. The monitoring and evaluation methods implemented to verify the long-term performance of these systems are also discussed.By offering a cross-cutting perspective on the role of soils in urban projects, this contribution aims to show how soil engineering and nature-based solutions can be integrated in a coherent and pragmatic way into real-world operations, and how these approaches help to build more adaptive, functional and resilient urban landscapes.