City-level implementation of nature-based solutions for adaptation

The 5th Open European Day conference took place in Bonn on 25 April with over 180 participants including city representatives, universities and research institutes, international organisations, NGOs, commercial consultancies and freelancers, and regional governments. Convened by ICLEI and EEA, PLACARD (for the third consecutive year) co-organised the conference together with the projects RESIN and SMR. This year’s main themes were:

  • incorporating adaptation
  • collaborative adaptation
  • implementation and monitoring.

PLACARD members were involved in the organisation of two sessions: Implementing nature-based solutions for adaptation, and monitoring and evaluation for urban adaptation.

Implementing Nature-Based Solutions for adaptation

Nature-based solutions (NBS) has proved to be a cost-effective measure for adapting cities to climate change, and for reducing the risk of current and future extreme weather events with the added advantage of bringing multiple co-benefits. However, implementing NBS is complex and advantages as well as disadvantages need to be considered together with other types of solution when developing adaptation strategies and plans. This session aimed to:

  • understand how NBS can be used within a pool of adaptation options
  • discuss the motivation behind and the benefits of using NBS
  • provide an overview of the methodologies and stakeholders involved in making the decision to use NBS in city adaptation plans.

Facilitated by Lea Kleinenkuhnen (Covenant of Mayors Office), the session brought together three cities from different parts of Europe to share their experience on implementing NBS: Copenhagen (Lykke Leonardsen), Cascais (João Dinis) and Thessaloniki (Eleftheria Gavriilidou).

Lykke Leonardsen shared the Copenhagen experience in the creation and implementation of their cloudburst management plan. Dealing with large amounts of water and avoiding floods would be difficult and expensive through enlarging the sewage system. As a result, it was decided to use natural paths to guide excess water to small natural catchments within the city. The plan allows the city to deal with a 100-year extreme rain event. It was clear that the water drainage modelling undertaken in developing the plan was critical to support the decision-making process. A few challenges had to be overcome in the implementation, such as the uncertainties of climate projections, dealing with the dynamics of a city, for example, growth; find ways to use the same infrastructure for different purposes, for example using roads for normal transportation and as well as temporary water channels and basins; and encouraging different teams and departments to work together, who often have different perspectives and languages.

For Cascais, João Dinis explained how the reconstruction of the Vinhas river bed was restored to manage flooding, bringing a range of multiple benefits, in particular, as a space for leisure for citizens (take a look at the video, in Portuguese). This option was chosen instead of a traditional water dam as the cost-benefit ratio was preferable and it offers multiple co-benefits, for example,  increased biodiversity and more green spaces for leisure. It was clear from Cascais’ experience that the cost-benefit analysis was an important factor in helping the decision-makers’ conclude that renovating the river bed was preferable to renewing the drainage system. Implementation of NBS is considered to be a very important element of the success of the city’s adaptation plan. The plan was developed in collaboration with research groups from universities and in consultation with a large number of stakeholders.

Eleftheria Gavriilidou described how the city of Thessaloniki considered a more social perspective on the use of NBS. The KIPOS3 project is creating a network of urban vegetable gardens in the city under the stewardship of the Municipality. The city was not planned with nature in mind, and is has a high density of urban structures. The project began as a pilot experiment of 800 m2 with the aim of engaging citizens and encouraging them to build a series of vegetable gardens. This created green areas that also work as social spaces, which helps to increase cultural resilience. Thessaloniki’s experience showed that citizens are very willing to embrace such initiatives as it allowed local communities and neighbourhoods to have a voice and some responsibility for the implementation.

The three cities had few, if any, available resources for consultation or help with the planning and implementation of NBS. All three had to find their own way to best implement such measures. However, it is clear that they all consulted with a range of stakeholders and benefitted from the collaboration with universities and research groups. NBS is still a difficult concept to “sell” to the decision-maker as a reliable option when compared with typical engineering solutions. In this case the use of cost-benefit analysis played an important role in supporting the decision-making process.