IAHR_1_S1.3/WLR_Special: Nature-based solutions for Cities and urban watersheds

Urban areas are facing multiple challenges: weather extremes caused by climate change, biodiversity loss, high resource and infrastructure demands. Nature-based Solutions (NbS) can play a vital role in addressing these challenges, but they are required to fit into the realities of cities. Although nowadays “greening the city” is an agreed objective, mainstreaming multi-benefit urban greening is not straightforward as there is a high competition for space and uses of space. This significantly limits the application potential of purely Nature-based Solutions and suggest cities need to look for hybrid blue-green-gray solutions. Due to the high competition for space, NbS need to be multi-functional to become a feasible option. To effectively address the present challenges, the embedding in and the retrofitting of existing infrastructure is often necessary. Yet, this is not just a technical challenge. It is a challenge which often requires transformative socio-technical change, i.e. the multifunctional design requires structured approaches on how to co-design in a participatory manner and how to introduce solutions aligned to multiple stakeholder interests.

Session topics

This session will cover real-life case studies and innovative approaches of NbS in cities and urban watershed around the world in the form of oral presentations. These presentations will link scientific understanding with practical experience, implementation challenges and impact delivery and measurability. They will cover various aspects around understanding how NbS can be used to increase resilience in cities and urban watersheds. It focusses on: i) ‘on the ground’ and ‘hands on’ practical experience of NbS techniques and challenges to implementation (e.g. retrofitting and multifunctional design, co-creation of solutions); ii) the key evidence that is needed to unlock financing; iii) aspects of NbS infrastructure operation and maintenance; iv) legal/governance dimensions, and v) policy alignment, particularly linked to the adaptation and decarbonisation agendas and commitments of cities.