With just around 14,000 inhabitants, Dragør is one of the smallest municipalities in Denmark. Situated on the southern tip of the Amager island, Dragør lies only 12km from Copenhagen City Hall Square and close to Copenhagen Airport. The land is generally flat and woodless here, except for a state-owned forest, Kongelunden, in the western part of the municipality. Dragør is therefore particularly vulnerable to rises in sea level, storm surge events, and to some extent also extreme rainfall. Climate change adaptation became a priority for Dragør when the 2007 local government reform transferred responsibility for open-countryside planning to the municipality. Moreover, there were plans to increase the height of the dike protecting West Amager, and this would also influence the future dike in Dragør. Climate change adaptation was therefore incorporated in the planning strategy from as early as 2007. In 2009, the municipality introduced its climate strategy, and in May 2010 a municipal development plan was adopted which included a green/blue plan. Thus, the Municipality of Dragør was well prepared when, in 2012, the Government and Local Government Denmark required all municipalities to prepare climate change adaptation plans.
Reinforcement of the existing 7-kilometer-long coastal dike from Kalvebod to Kongelunden on West Amager was commenced in July 2007, and the new dike was officially inaugurated in August 2012. The existing coastal dike was raised by around 2 meters. From 2007 to 2012, the drainage association Vestamager Pumpedigelag reinforced the existing 7-kilometer-long coastal dike from Kalvebod Commons to Kongelunden on West Amager (known as the Kalvebod Dike). As a result, the Øresund motorway, the Øresund rail link, the Metro and the residential areas in Ørestad and Tårnby are now less vulnerable to storms and increased sea levels in Køge Bay. The drainage association's original plan included the establishment of an additional land dike from Kongelunden to the town of Ullerup in order to protect the built-up areas and the subsurface structures of the Øresund Link. However, in 2011, the Danish Nature Agency suggested an alternative routing of the land dike (called the Kongelund Dike) through Kongelunden. Because the forest is owned by the state, this alternative routing will not involve having to expropriate privately owned land. Furthermore, it will be possible to prepare a holistic plan for the southern and western parts of Amager. Therefore, a project group was set up with representatives from the Municipality of Dragør, the Municipality of Tårnby and Vestamager Pumpedigelag as well as the Danish Nature Agency, Metroselskabet, Ørestad, City & Port Development and the Øresund Link. The group was tasked with establishing a decision basis for choosing a solution that will provide protection for both municipalities and for the other parties involved.
Protected coastal meadows viewed from the Kongelunden fortress The land is prone to flooding and has vegetation and wildlife that thrive in salt-affected environments. The decision about the location of a dike was significant for the design of the Municipality of Dragør's climate change adaptation plan, which was adopted in June 2014. "Everyone agreed that it was a good idea to think holistically. The expectations for protection of the Øresund Link, the Ørestad district and the Metro are based on the assumption of a 10,000-year event, whereas here in the municipality we are talking about a much lower event-level," said Jørgen Jensen, who is head of the planning and construction department at the Municipality of Dragør. Jørgen Jensen and the head of the technical and environmental department at the municipality, Jesper Horn Larsen, have primary responsibility for climate change adaptation initiatives in the municipality. "We feel that the Kongelund Dike is a good collaborative solution which enables us to achieve results that are both effective and attractive. The dike through Kongelunden has been envisioned as a landscape project - as a feature of the landscape running through the forest, and the dike will moreover not be especially high because it is placed so far inland from the coast. The dike will have a height of around 3.5 metres, however since the ground is at a spot height of around 2.3 metres, the dike or plateau will be between 80cm and 1.5m high," said Jørgen Jensen. Jesper Horn Larsen added:"Previously, we thought that we would have to find one technical solution - the single right solution. However, now we are working on a hierarchy of solutions, so it is also about finding a solution that fits well into the landscape.
In the Municipality of Dragør's climate change adaptation plan there are four different dike scenarios for the south-western part of the municipality. These will have to be prioritised at a later stage. In Dragør, work has been centred around the principle that climate change adaptation solutions should be designed as a natural and integral part of the landscape, as far as possible.
Scenario 1: The Kongelund Dike is combined with a coastal dike along the coastal meadows.
Scenario 2: The Kongelund Dike is combined with a continuous coastal dike away from the coast and following the edge of the built-up areas and the forest.
Scenario 3: A combination of the Kongelund Dike and several local ring-shaped dikes around the build-up areas.
Scenario 4: A coastal dike inserted between the cultivated land and the coastal meadows.
The decision about which scenario to realise will depend on a comprehensive analysis which is expected to result in a decision basis for dike sitings in the municipalities of both Dragør and Tårnby. At the same time, coastline along Køge Bay and South Amager has been designated by the EU as one of ten 'risk areas' in Denmark likely to be hit hard by flooding if exposed to extreme storm surge events. In this context, the Danish Coastal Authority has performed analyses of the possible scope and implications, followed up by municipal risk management plans. These planning efforts will also be included as a part of the decision basis.
Good communication efforts are a prerequisite for arriving at good municipal climate change adaptation solutions, according to Jørgen Jensen and Jesper Horn Larsen. Work in the project group is a good example of this.Furthermore, strengthened communication efforts aimed at the public have also paid off. For example, as an introduction to work on the climate change adaptation plan, the Municipality of Dragør arranged a popular event at which the public could join a trip by foot and by bus along the coast, during which they were told about storm surges in Køge Bay and were introduced to the four dike scenarios. Furthermore, the municipality has endeavoured to write its climate change adaptation plan in easy-to-understand Danish and it has made an effort to explain the implications of climate change for a municipality like Dragør, with vulnerable coastal land, and to explain how the municipality is working with climate change adaptation. "Initially, we were worried that the public would be frightened, however we were not bombarded with inquiries from the public - far from it. A few people are concerned and nervous. However, most people have expressed that they are confident we are taking care of things. The local politicians have been pleased to have a well-written document which provides them with a holistic view of things, so, all in all, we think that, generally, we have succeeded in raising the level of knowledge about climate change and climate change adaptation in the Municipality of Dragør. This is a good vantage point for future work, said Jesper Horn Larsen.
The Hovedgrøften water course which runs through the landscape in a straight line from Copenhagen Airport to the Sound plays a key role in Dragør's open-countryside planning.
A key problem for the Municipality of Dragør has been whenever the Hovedgrøften watercourse, which drains the low-lying fields, has breached its banks during extreme rain events. Previously, these flood events have resulted in compensation claims from landowners, however in recent years the municipality has entered into collaborations with landowners to find durable solutions.
"We have examined several different opportunities for improving conditions for landowners. Amongst other things, we have looked into whether we can expand the watercourse, however this has not proved possible. We have also looked at whether building a weir at the end of Hovedgrøften would be an option. This would make it possible to pump the water out, however the watercourse would overflow before the water reached the weir," Jesper Horn Larsen explained.
"We ended up with a solution in which the individual landowner protects his land against backflow from the watercourse by cutting off the water so that it cannot flow back through the drain and up into the fields. At the same time, we will raise the banks of the watercourse where they are most exposed. This will limit the damage. "With time, when talking about sea level rises, it may be that we will have to close off the estuary to the Sound, however would also require that we do something upstream, otherwise this would be to no avail," he said.
By looking at solutions for Hovedgrøften, we were able to dismiss a hard-dying myth that drainage from the airport causes the watercourse to overflow.
"The airport has carried out extensive adaptation on its own turf, so we can't blame them. We and the public have grown considerably wiser," Jesper Horn Larsen explained.
In collaboration with the utility company HOFOR A/S (formerly Dragør Spildevand A/S), the Municipality of Dragør has prepared a local emergency response plan with regard to cloudbursts. The overarching aim of this plan is to ensure that the sewer system will be able to function during a flooding event. In connection with the climate change adaptation plan, the municipality checked the spot heights for the existing dikes along the coast and observed that the dike needs to be reinforced in some places. Furthermore, it has become relevant to update the emergency response plan with regard to high water levels. "We are taking a fresh look at the emergency response plan in light of the new models we have had made. We would like to have an emergency response plan that is more accurate. The idea is to make the plan more preventive by making it chronologically dependent upon an anticipated course of events. This will mean that everyone involved will know more precisely what to do as an event develops; who is to be alerted; and where it is important to be particularly observant and ready to move in with sand bags, mobile dikes and pumps," said Jesper Horn Larsen.