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Green Cities for Climate and Water Resilience, Sustainable Economic Growth, Healthy Citizens and Environments

Periodic Reporting for period 3 - GROW GREEN (Green Cities for Climate and Water Resilience, Sustainable Economic Growth, Healthy Citizens and Environments)

Reporting period: 2020-06-01 to 2022-11-30

The aim of GrowGreen is to deliver support for the development and implementation of Nature Based Solution (NbS) strategies in cities around the world, bringing systemic changes to long-term planning, development, operation and management.

The cities of Manchester (UK), Valencia (ESP) and Wroclaw (PL) each created their own demonstrator pilots. Together they looked at the ways NbS and Sustainable Urban Drainage Systems (SuDs) can help to adapt cityscapes to a climate change using raingardens, swales, tree pits, permeable pavements, storm water infiltration trenches and basins. The project learnt from the Chinese City of Wuhan, also a partner, and their involvement in China’s dynamic and expansive ‘Sponge Cities’ programme. Sponge Cities’ is a concept to mitigate the impacts of excessive surface water and river flooding via construction projects which help soak up water or channel it safely.
The demonstrator pilots are a practical way to promote changes supporting city responses to climate change and as part of this, the project included three replication cities, Brest (Fr), Modena (IT) and Zadar (HR) with a role to learn and apply the outcomes.

Monitoring has shown the ability of NbS features to reduce urban runoff and enhance water quality, the ability to provide CO2 savings via sequestration and impact on the Urban Heat Island effect as well as improve biodiversity. Whilst the driver was to improve climate and water resilience, there were other co-benefits to be achieved. Extensive research looked at community engagement, participatory planning, the impact on health and wellbeing, influencing city governance and the future delivery of NbS in urban environments.

GrowGreen has provided an abundance of opportunities, offering a global platform to share best practice and to continue collaborating, improving and learning. The impact on the strategies and governance has been significant with administrations adopting new approaches, reflecting the shift in EC policy to ensure that H2020 funding continues to deliver excellent science and achieves practical impact for the benefit of citizens and businesses
The starting point for GrowGreen was the involvement of stakeholders in the design of the pilots using participatory planning processes. The three cities each constructed NbS projects:

• Manchester - a new amenity park with three interconnected areas: woodland; meadow and a community plaza garden with a flexible event space and community growing spaces.
• Valencia - a Sustainable Forest, a green-blue corridor along an urban street, a vertical ecosystem, a green roof and community initiatives e.g. a growing project, meeting space and biodiversity app.
• Wroclaw - internal courtyards within residential housing blocks and a green street in one of the city’s most densely populated districts.
Detailed monitoring and evaluation plans were developed covering a range of climatic, environmental and social indicators. Baseline diagnostics looked at climate, air and water quality, health, water management, noise, green space and soil contamination, as well as the social and economics. The focus was to improve climate and water resilience and also to look at the co-benefits of engaging with the local community, stakeholder participation and influencing city governance and the future of NbS in urban environments. The evidence based outcomes demonstrate:

• Water management and flood risk: NbS features may differ in type, size and construction but hydrological processes are similar. The outcomes of monitoring show the ability of NbS features to reduce urban runoff with a higher than average performance figures (99-100%).
• Heat stress: the baseline data shows the cities are all dealing with an increase of temperature. The heat intensity outcomes conclude NbS can reduce the occurrence of heat stress and provides evapotranspiration.
• CO2 savings: NbS on buildings can have an immediate impact by using plants and organic materials with immediate benefits on the thermal behaviour of the building. Carbon sequestration in trees and vegetation has a significant role.
• Biodiversity: all the demonstration areas show significant biodiversity uplift as a result of the introduction of trees, shrubs and herbaceous plants and the protection of mature trees.
• Water quality: NbS features have the ability to ameliorate and reduce contaminated runoff.
• Social and participatory research: the process and provision of NbS benefits from a participatory planning approach, engaging the local community creates a sense of ownership. There are tangible impacts on health and wellbeing.
• Financial benefits: the financial implications of NbS are challenging to quantify and need longitudinal studies.
• Management and maintenance - SuDs need a bespoke maintenance schedule with the need for those responsible for maintenance have an understanding of the issues.

The project results are available in accordance with Horizon 2020 Open Research Data Pilot (ORDP) as follows:
• Manchester – research results
• Valencia -
• Wroclaw -
Going forward, the pilots will all be monitored for the next 5 years (up to 2027) with the results made available as above.
GrowGreen has provided an abundance of opportunities, offering a global platform to share best practice and to continue collaborating, improving and learning. The project has produced an easy-to-use replicable approach to support the development and implementation of NbS strategies in cities and deliver social, environmental and economic benefits. The Green City Framework is a template for cities starting on the journey of green infrastructure strategy development
The demonstrator pilots are a practical way to promote change and support city responses to climate change. The impact on the strategies and governance has been significant. Each of the partner cities have enhanced and developed the role of NbS in their own strategies. In Manchester, GrowGreen had a direct influence on the design of the first new park in to open in the city for over 100 years. In Wroclaw all municipal investments must include NbS, e.g. green tram tracks are now standard.
Particular elements of the project stand out in terms of innovation. The participatory planning processes included local residents and as well as a wide group of stakeholders. This ensured the design drivers relevant KPIs were included as well as engendering a sense of involvement and ownership. The design features have introduced new approaches. In Manchester, rainwater runoff is redirected from the roads by NbS features. Educational signage includes information about climate change and NbS. The project developed a deeper understanding of the need for SuDs management plans and bespoke maintenance schedules. There was market analysis was undertaken to gain insights into the current NbS market, the barriers development and future market potential.
Valencia Benicalap demonstration area BEFORE
WRO - completed courtyard
Data monitoring post project
WRO - completed green street
MAN - completed park - boardwalk over dry pond
Manchester West Gorton Photograph of Demonstration Site Area BEFORE
VAL - completed Green Roof
VAL - completed green wall
MAN - completed park - drainage rill
Wroclaw Olbin courtyard BEFORE