GrowGreen Final Conference “Cities of the future: nature-based solution for resilience in the face of climate change”

On the 8th and 9th of November, GrowGreen hosted its final event in Brest (France):
“Cities of the future: nature-based solutions for resilience in the face of climate change”
. The event was organised by IUCN and Brest Metropole, with the support of the GrowGreen partners.

As the evidence base on the role and benefits of NBS grows rapidly, these solutions are featuring with increasing prominence in global climate change policy, stressing the importance of their implementation in urban environments. GrowGreen has worked to create climate and water resilient, healthy, and liveable cities through investing in NBS in the partner cities of Manchester (UK), Valencia (Spain), Wroclaw (Poland), Brest (France), Modena (Italy), and Zadar (Croatia), including collaborations with Wuhan (China).

The work carried out by the GrowGreen cities has generated extensive knowledge, best practices, and lessons learnt on the implementation of NBS in different urban contexts. During the final GrowGreen conference, the GrowGreen partners, as well as other EU projects on urban NBS, shared their success stories, lessons learnt and challenges encountered. This event provided opportunities for cities representatives, local and regional authorities, practitioners, business representatives, policymakers and local stakeholders to engage in discussions on how to scale up NBS, exploring strategy development processes, innovative planning, governance and financing.

The first day (8th of November) of the event was open to the public and included plenary as well as parallel sessions.

Frédérique Bonnard – Le Floc’h, vice president of Brest Métropole, opened the GrowGreen Final Conference with a welcome speech.
Climate-change has had significant consequences in the area of Brest. The issues caused by droughts were tangible all over Europe, with rivers drying up and many water use restrictions being applied. In times of crisis adaptation is crucial, but it must be done in a coordinated manner and through cooperating actions.
In order to achieve the EU’s objective of becoming carbon neutral by 2050, we need solid mitigation and adaptation strategies covering all sectors, and involving all the relevant stakeholders. Cities have a leading role in directing these changes. GrowGreen is the perfect example of urban efforts.

Michelle Oddy, the GrowGreen Coordinator from Manchester City Council, highlighted the changes that have happened since the start of GrowGreen in 2017. The role of NBS and the value of nature have become more broadly understood. The event represents a great opportunity to discuss how to further upscale NBS in the current context.

Achievements, impacts and lessons learnt from GrowGreen

Successively, the various GrowGreen partners shared their achievements, impacts, and lessons learnt throughout the project, linking to the experiences of the cities.

The city of Wuhan was represented by Prof. Xiang Zhang, Director of Experimental Research Centre of Hydrology, Wuhan University, and it was brought as a successful case study example of ‘Sponge City’.
In 2015-2016, following significant issues in relation with the water network in China, 30 cities were selected as pilot sponge cities: Wuhan was one of the first cities to apply the sponge city strategy. Two lakes located in Wuhan were chosen to integrate a hydro-dynamic and systematic strategy, to study the function of green infrastructure in order to connect the urban water cycle components to each other, from the source to the ending point. Raingardens and other water management interventions were included in the monitoring phase. The sponge city interventions made very tangible changes, in fact the project received good feedback and citizens’ appreciation. The sponge city concept has become an example of urban green developing patterns in China and beyond, yet the green-grey-blue combined systematic thinking should be further emphasised and developed through cooperative operations. More information about the Wuhan Sponge City Programme can be accessed here.

Igone García, from TECNALIA, showed the results of the GrowGreen project in terms of heat stress. Severity and recurrence of heat waves is increasing, which in urban areas can significantly decrease human wellbeing and quality of life. The impacts of the implementation of NBS for thermal comfort were monitored in 3 cities, demonstrating their contributions to increasing climate resilience in relation to heat. Shadowing, albedo, and evapotranspiration are the main factors through which NBS contribute to reduce heat stress. Yet, it is important to identify the climate context, to provide specific and effective NBS for heat stress reduction. More information on heat stress results can be accessed here.

Kornelia Kwiecinska, from WUELS, showed the results of the GrowGreen project in terms of biodiversity. Urban growth can significantly contribute to biodiversity loss. Urban NBS provide the opportunity to halt and revert this trend, through introducing blue-green infrastructure to densely urbanised areas, combined with biodiversity supporting features and educational campaigns.
In Manchester, Valencia, and Wroclaw, a blue-green infrastructure was integrated as pocket parks, urban green belts, green walls and roofs, and city sponge parks.
A significant biodiversity uplift resulted from all the demonstration sites. Besides the protection of mature greenery, diverse vegetation was introduced, aiming for adaptation to the local conditions with appropriate selection of plant materials.
The lessons learned are that biodiversity scores can be significantly affected by upkeep and maintenance operations, and that the new vegetation should receive particular care. Future research should investigate the most suitable species for urban areas, through monitoring the maintenance need and adaptation capacity of the vegetation. Once the demonstration areas reach maturity, it will be possible to also monitor the fauna. More information on biodiversity results and monitoring tools can be accessed here.

James Rothwell, from the University of Manchester, presented the results in terms of water runoff mitigation. In Manchester, several interventions were applied in order to manage water runoff in the West Gorton Community park. Swales (ditches), raingardens, and tree pits, were monitored in terms of inlet and outlet of rainwater to verify the effectiveness. To ensure that these interventions can reach their potential, maintenance and management are absolutely crucial. The final results of the monitoring were impressive, recording an average reduction of the water runoff between 88% and 100% with the implementation of NBS. Therefore, this project showed the effectiveness of NBS features in reducing urban water runoff, despite the small scale. More information on the water runoff results can be accessed here.

Ignacio Andrés Doménech, from the Universitat Politècnica de València (UPV), presented the impacts, achievements and lessons learnt from GrowGreen in relation to water quality. The main impacts on water quality are monitored through the runoff from the streets, the permeable pavement underdrain outflow, and the filter drains underdrain outflow.
The NBS interventions in Valencia achieved a high efficiency in pollutants capturing, close to 100%, because most of the water is retained and consequently does not convert into wastewater. In conclusion, identifying the potential sediment sources, and understanding the maintenance needs of NBS is fundamental for the long-term successful application of these solutions. More information on the water quality results and variables assessed can be accessed here.

James Rothwell, from the University of Manchester, talked about the results of GrowGreen in terms of social benefits.
There were three main social challenges targeted by this project: participatory planning and governance, social justice and cohesion, health and wellbeing. The NBS interventions have resulted in positive impacts on communities, supporting the development of a sense of belonging, increasing community integration, providing a comfortable public space for leisure, thus encouraging physical activity. This is impacted by the NBS design which should aim for openness and connectivity. More information on the social benefits can be accessed here.

Oana Forestier, from Trinomics, presented the results of GrowGreen in terms of economic benefits. To monitor the economic impacts a range of KPIs were measured in Valencia, Wroclaw, and Manchester. Two types of impacts were found as most relevant: the health benefits and the property values. Physical health was quantified in terms of decreased costs for health care. The impacts of mental health were not possible to consider, however it is expected that they would add significant value. As regards to property price, NBS have been found to contribute to increased land value, mostly because of aesthetic benefits.
In conclusion, the total net benefits of NBS projects exceeded significantly the implementation costs. More information about economic benefits can be accessed here.

Alejandro González, from Bipolaire, presented the NBS Co-design Guide. The guide aims to tackle the problems encountered by the various GrowGreen city partners. Different cities followed different paths and strategies. The guide can be used to consult case study examples, to understand how to deliver a successful NBS co-designed project, and to ensure it supports collaboration through stakeholder involvement. To access the Co-Design Guide click here.


Sharing experiences and results from EU projects on NBS in urban and peri-urban areas

The event continued with a moderated panel discussion, gathering representatives of four urban NBS projects, namely UNaLab, CLEVER Cities, Connecting Nature, and GrowGreen.

Main challenges

For the GrowGreen project, Michelle Oddy (Manchester City Council) talked about the challenge of getting the different departments to engage collectively and collaborate on this agenda. It was a struggle to get the parks department engaged, as well as high-ways engineers. While the policy officers and politicians were onboard, in all frontrunner cities, it has been difficult to get the community engaged and onboard.

Marcus Collier introduced (Trinity College Dublin) introduced ConnectingNature and its objective to look into silo thinking. The project developed a framework to identify the key actors to bring on board for NBS. An example of successful application is the Steamer Hub in Genk. The framework allowed to have a process to work with the city and the community, which was also used to generate funding for NBS in follower cities. It is through such a process that silos can be crossed, but continuous work and high-level commitment is needed.

For the UNaLab project, Laura Wendling (VTT) stressed the importnance of having representatives in all cities who are very enthusiastic and engaged in the scope of the project. This helps maintain positivity and overcome the barriers. The EU policy landscape can be also of support, e.g. the Nature Restoration Law.


According to Laura Wendling, as regards financing NBS, anything can be valued. If we opt for public  investments on NBS, tax payers are contributing, so it is important to show what are the possible benefits. Further, the recurring danger of seeing NBS as offsets, requires anyone working on NBS to contribute to overcoming the risk of greenwashing.

Igone Garcia (TECNALIA), representing the CLEVER Cities project, added that, nowadays, there is more a feeling of urgency on climate. Now many more cities are interested in working on NBS projects: there is research funding for it, and a learning by doing process.

Public acceptance, political leadership and replication

In the context of CLEVER cities, it emerged that NBS deployment cannot depend only on the awareness of a specific politician. Awareness needs to be more operative, from the specific practices to more general applications (from a demo to actual guidelines).

In GrowGreen, the evidence is available and the policy agenda is developing. In Manchester, there is a Green Infrastructure strategy to deliver on this agenda. However, even if the tools to scale up NBS are available, persuasion and influence can only go so far. The next step is to obtain mandates and legislation to go forward.

The UNaLab has witnessed great support for NBS. COVID has helped to make people recognise the importance and value of nature. A high increase in the amount of time people spent outdoor, in green spaces, could be observed. This has translated into more support for green and blue spaces in urban centres.


The different projects have been working on digital solutions, such as the ConnectingNature Enterprise platform which brought businesses together, and the online platform for co-creation for citizens in UNaLab. In addition, CLEVER Cities is working on a specific guide on how citizens can gather and share data (through apps).

Michelle Oddy pointed out that cities are increasingly inspiring each other. The Task Forces of NetworkNature have helped bringing actors and projects together and share learnings.


Panel: Regional and local perspectives on NBS: French examples

A conversation-style panel followed, highlighting the regional and national experiences and success stories with NBS in France, which involved Gilles Lecuir, from the Paris Region Biodiversity Agency, Alain L’Hostis, from REDAGIEO (Network of integrated water management stakeholders at the scale of Western France), and Michel Benard, from Infra Services and Elleny. According to the experts, the main motivations for integrating NBS in urban areas are economic, as integrated rainwater management systems allow up to 20% savings in new developments, and environmental, as there is increasing recognition of the biodiversity crisis in agricultural and urban areas. As regards to barriers to NBS implementation, lack of knowledge, of leadership, of adequate policies, in particular for creating economic frameworks, were mentioned as well as silo thinking. As a response to these challenges, capacity building can contribute to successful implementation of new techniques. Pioneer communities are at the origin of transformations. Further, politicians’ commitments to upscaling NBS are crucial as they pursue the transformation started by citizens.

The experts summarised different experiences across French regions and cities. In Western France, REDAGIEO as a network for integrated water management has been responding to the abovementioned barriers by showcasing experiences, networking and capacity building with different stakeholders, including private and public sector and politicians. The Région-Île-de-France, as a highly dense area counting 2% of the surface and 20% of the population of France, has focused on halting land take and reversing soil sealing for protecting agricultural areas, assuring potable water availability and avoiding the heat island effect. In Liége, there is a project for zero-rainwater in the sewage system and in the Metropole de Lyon there is a Plan Canopeé, whose objective is to create a link between the Tree Charter and the Territorial Climate and Energy Plan previously adopted, representing a good example for managing biodiversity.


Parallel sessions

The audience was then split into two parallel sessions to engage on discussions on different aspects of NBS deployment.

The first parallel session “NBS strategy development: building political commitment and stakeholders’ engagement” was led by Dave Barlow from Manchester City Council. It involved a presentation on Manchester’s Green & Blue strategy development followed by a discussion on the barriers and challenges in the planning and implementation of NBS.  Some of the key challenges identified were funding & resources, political will, silo working, competing priorities, and external factors such as COVID. Groups were given the chance to propose solutions to the key challenges which included raising awareness, empowering citizens to act and challenge politicians, evidence value and make business case for NBS, provide mechanisms for better cross-thematic dialogue to help embed, and develop projects with co-benefits.  “Be creative in your response to challenges – it’s not just about money”.

The second parallel session “Innovative planning, governance and financing enabling NBS deployment for water and climate change resilience” was led by Gemma Garcia, from TECNALIA. It involved a discussion on the key barriers and challenges in the planning and implementation of NBS. Examples of spatial planning for NBS were discussed, to figure out key barriers and enablers of top-down measures for NBS. Fear of change, greenwashing, business as usual were examples of recurring keywords in the constraints encountered. While research and innovation, support of local authorities, political timing and interest, and financial incentives were mentioned as possible enabling factors for planning and implementation of NBS.



The event concluded with some closing speeches and remarks.

Andreas Wolter, Climate Alliance President and Mayor of City of Cologne, held a keynote speech on broadening NBS horizons. He pointed out to the current objective of cutting emissions by 55%, which is a sign of the generational transformations of the economy towards sustainability. As the dire effects of climate change are already hitting us, he referred to the IPCC report as our last warning and called for more efforts towards climate adaptation, through financing and support at national and EU level. The transition is doable if all non-state actors (including cities) work in the same direction and are fully empowered. Local communities need to be equipped not only with money but also with human and technical resources to use it. He concluded his speech by mentioned the efforts of the city of Cologne which has been working on climate-resilience, with the objective of becoming climate neutral by 2035.

Valerie David, general director of Public Spaces and Environment in Brest Metropole, talked about NBS and climate related policies in Brest.
She stressed the importance of exchanges such as those which took place during the conference. Beyond differences, we can question ourselves to see what is good in other’s approaches and actions.   Actions can only be legitimate if understood by the citizens, and this can lead to their engagement. Finally, understanding the benefits is also crucial to make a change in the economic model.

Finally, Michelle Oddy, GrowGreen coordinator from Manchester City Council, added a few closing remarks to conclude the session of the 8th of November, particularly thanking the organisers and participants of the event.

To conclude, the videos from the various GrowGreen cities were shown.

On the 9th November, guided visits were organised to explore several NBS sites in Brest.