Lars Kildahl Sønderby is a forest and landscape engineer working at Odense Municipality, Denmark. As a member of the RECONECT project consortium, he is leading one of the demonstration sites of Nature-Based Solutions with the potential for upscale.
What are the drivers for using Nature-Based Solutions in Odense Municipality?
The Seden Strand project area is just four kilometres outside of Odense, Denmark’s third largest city. Located on the shore of a fjord of the Baltic Sea, the small settlement of 142 houses with bordering agricultural areas and a nature conservation area is one of ten flood risk areas in Denmark. In the recent ten years an increase in frequency of floods has been observed, requiring immediate measures. Climate change and sea level rising will even further increase the risks.
In the RECONECT project, Odense Municipality wants to demonstrate how to combine the interests of minimizing flood risk of the suburban as well as agricultural areas with improving habitats in the ‘Natura 2000’ area, while conserving the coastal landscape. Lars reflected that “Nature-Based Solutions (NBS) are a means for us to combine interests of different stakeholders”. For example, the project area is an important habitat for domestic and migrating birds, and is also a natural habitat of the Natterjack toad which has now disappeared. Accounting for nature allows the municipality to work with partners to solve multiple issues with a holistic approach. There is a need to protect against floods and conserve nature; Nature-Based Solutions can address both while creating extra value for all.
What type of Nature-Based Solutions are being used?
On the East side of the settlement the existing dikes provide insufficient protection against floods. Lars explained that the plan is to re-locate these dikes inland to higher ground, closer towards the settlement. The gained area in front of the dike (27ha) is then converted from current agricultural use to natural habitat, through a so called ‘self-design’ rehabilitation process. This natural habitat is expected to undergo a dynamic succession into salt meadows. Disconnecting existing draining canals will further promote more natural hydrology of the salt meadows. Restoration of the habitat for toads and migrating birds creates a landscape with rich biodiversity, as well as flood risk mitigating properties. These planned actions complement efforts for the whole Natura 2000 area, where there is a problematic decline of habitats for birds depended on the coastal habitats.
Together with the support of the municipality, the local community must prepare for storm induced floods which are expected to reach up to 2.4 meters. Moving the dikes to higher ground enables better flood protection as there is more buffer area in front of the dikes, and at the same time it reduces the relative height to 1–1.5 meters. The aim is not to just relocate and rebuild the dikes, but to integrate them into the natural landscape to protect the coast line appearance. Animals will be able to graze on parts of the dike making it easy to maintain. The design of the slope facing the sea is further modelled to allow for the optimum creation of additional habitat for various plant and insect species.
The expected benefits of the project are:
· Improved protection of populated and agricultural areas.
· Improved and increased habitats within the Natura 2000 area including more room for the sea and natural meandering of local streams.
· Conserving the coastal landscape from major technical installations and improve access to nature for the population in general.
What is the status of implementing the Nature-based Solution?
Planning for this project started already in 2014 with the development of a preliminary project. On that basis there have been focused, extensive consultations with stakeholders to ensure solid technical and financial planning, support from landowners as well as response and compliance with national and EU regulation. To date the financial compensations have been paid to landowners for their farming rights, whereby grazing is partly still permitted. The land acquisition for the project is therefore completed. Currently the detailed planning/design of dikes and area in general are underway. Following that the plan is to complete the physical re-construction of the dikes, streams and the rest of the area in first half year of 2020.
How are the different stakeholders working together?
According to Danish law, flood risk mitigation is the responsibility of landowners. The role of the municipality is to support owners and communities (on their request) through facilitation of the process of realizing measures against flood risks. At the same time, national plans and targets are translated into detailed action plans by the municipality and constitute an important framework for e.g. nature conservation objectives. As the local community asked the municipality for support, it has been possible for action to be taken with costs covered by local taxes regarding actions on the west side. On the East side of the settlement, which covers the project area, the municipality has taken a leading and proactive role because of the doubled responsibility related to both the Natura 2000 area and flood risk management. It is of great importance for the municipality to ensure a sustainable solution which fulfils these responsibilities. Lars stated that “on the one hand, we have the obligation to conserve the coastal habitats, and on the other hand we want to support the community in adapting to increasing flood hazards. We see working with nature as a way to combine both interests, by designing measures that serve both purposes”. Farmers and landowners, but also NGOs such as the Danish Birding Association (Dansk Ornitologisk Forening) are important local stakeholders that are being involved in the consultation process, the design and later the implementation. Reallocation of land from farming to nature had required careful negotiation with all actors.
Are there additional co-benefits expected?
By improving both flood protection and rehabilitation and expansion of natural habitat, there is added value for the surrounding area. One example of specific co-benefits that are expected relate to property prices. The value of houses will increase not only because of the reduced risk of flooding, but also because of the recreational and aesthetic value of the expanded and restored nature area close by. Creating habitats explicit for endangered species that have lost their natural habitat in the region will restore biodiversity and is expected to attract visitors to the created observation stations and pathways. Further, the approach taken in this project, the successful combination of interest of different stakeholders in one holistic approach is expected to form trust between the actors involved in this project, and act as basis for future collaboration and expansion of the approach.
Where do you think the approach can be up-scaled and what is needed to do this?
The experience in Seden Strand has the potential to be replicated across Odense and Denmark. Lars pointed out that “we have many protected coastlines in Denmark that deal with the same problems we face in Odense. The potential for upscale are great. What we need to find out through this project are the exact added values that our NBS bring with them.” The exact added benefits from nature are thereby often difficult to quantify. In order to address this issue, using the results from RECONECT it will be possible to put more evidence into the proposed added value of using NBS compared to a grey solutions. Development of a tool for easier comparison of NBS to grey solutions in specific areas could be one of the results of RECONECT. Looking at a larger scale, this is only a minor project, but with great potential to upscale the approach and implement NBS along the neighbouring coastline.
· NBS are not just technical solutions, but a holistic approach to solving multiple problems while improving natural habitat.
· NBS are an approach to combine the interests of stakeholders, to combine practical solutions with our responsibility towards the natural environment.
· Next to the costs of implementing and maintaining NBS, the co-created added values for society and biodiversity must be taken into account.
For more information visit the RECONECT project website.