🌳 GROW GREEN Project Summary: Nature-Based Solutions for Urban Resilience
The GROW GREEN project aimed to develop and implement Nature-Based Solution (NBS) strategies in cities globally to bring about systemic changes in long-term urban planning, development, and management. The central focus was utilizing NBS, specifically Sustainable Urban Drainage Systems (SuDS), to enhance climate and water resilience while generating significant co-benefits.
🎯 Approach and Implementation
The project centered around three demonstrator pilot cities (Manchester, UK; Valencia, Spain; and Wroclaw, Poland) and engaged the Chinese city of Wuhan to learn from its expansive ‘Sponge Cities’ program . Three additional replication cities (Brest, Modena, and Zadar) were involved to learn and apply the outcomes.
Pilot Demonstrators
| City | NBS Project Focus | Key Features Implemented |
| Manchester (UK) | New amenity park and community space. | Woodland, meadow, community plaza garden, rain gardens, swales, tree pits. |
| Valencia (ESP) | Green-blue corridor and vertical ecosystems. | Sustainable Forest, urban street greening, green roof, vertical ecosystem, community growing spaces. |
| Wroclaw (PL) | Densely populated residential districts. | Internal courtyards within housing blocks, green street with sustainable drainage. |
💡 Main Results and Evidence-Based Outcomes
The project used a detailed monitoring and evaluation plan covering climatic, environmental, and social indicators. The evidence gathered demonstrated the high efficacy of the implemented NBS features:
Environmental and Climatic Impact
- Water Management and Flood Risk: Monitoring showed the ability of NBS features to reduce urban runoff with high performance figures ($\approx 99-100\%$).
- Heat Stress: Outcomes confirm that NBS can significantly reduce the occurrence of heat stress through processes like evapotranspiration.
- CO2 Savings: NbS features (especially on buildings) offer immediate benefits on thermal behavior, and carbon sequestration in trees and vegetation plays a significant role.
- Biodiversity: All demonstration areas showed significant biodiversity uplift due to the introduction of diverse plants and the protection of mature trees.
- Water Quality: NbS features have the ability to ameliorate and reduce contaminated runoff.
Social and Governance Impact
- Participatory Planning: The project strongly validated that the development and provision of NBS benefits from a participatory planning approach, which successfully engaged local communities and fostered a sense of ownership and involvement.
- Health and Wellbeing: Demonstrated tangible positive impacts on community health and wellbeing.
- Management & Maintenance: Highlighted the critical need for bespoke maintenance schedules and dedicated SuDS management plans.
🚀 Progress Beyond State-of-the-Art and Legacy
GROW GREEN provided a global platform for sharing best practice and achieved significant governance changes:
- Green City Framework: Produced an easy-to-use, replicable approach called the Green City Framework, which serves as a template for cities starting their journey of green infrastructure strategy development.
- Strategic Influence: The project had a direct and significant influence on partner cities’ strategies. For example, in Wroclaw, all municipal investments must now include NBS (e.g., green tram tracks are standard), and in Manchester, the project directly influenced the design of the first new park in over 100 years.
- Long-Term Monitoring: All pilots will be monitored for the next 5 years (up to 2027), ensuring a robust, longitudinal data set on NBS performance is made publicly available.
- Innovation: The use of participatory planning processes to integrate local residents and stakeholders into the design, ensuring that relevant KPIs were included and engendering community involvement, stands out as a key innovation.
