Foto: Town and Country Planning Association
Storm Water Management and Urban Regeneration
A resilient flood protection system has revitalised the neighbourhood of Augustenborg, in Malmö. To address floods from overflowing drainage, as well as a decline in quality of life, a Sustainable Urban Drainage System (SuDS) has been collaboratively implemented as part of a larger regeneration project. The system has lowered the volume of storm water that flows from roofs and other surfaces into the sewers. This protects the residents from flooding during storms, which are expected to increase due to climate change. The project has improved the local biodiversity, increasing wetland habitat for animals and plants, and has provided additional spaces of recreation for the residents.
The Adaptation Journey
The positive impact
Augustenborg in Malmö, Sweden has experienced socio-economic decline, and has had to manage urban flooding caused by rainwater during storms, which flows into the combined sewers and causes them to overflow. To ensure the neighbourhood can manage current and predicted rainfall into the future and to increase its overall resilience, a collaboration was formed between water and city planners, the Malmo housing company and the local citizens. Working together in consultation, the partnership created a sustainable urban drainage system, which incorporates canals and water channels, as well as retention ponds which slow down and collect rain water during storms. 90% of storm water now runs through the open storm-water system, and peak flow rates have been reduced.
While the core purpose of the project was to address flooding, other socio-economic have been taken into account in the project’s goals. These include an improvement to the liveability and aesthetics of the neighbourhood, leading to the creation of new spaces for communal activities, opportunities for business development in water innovation, and increased habitat for invertebrates, aquatic plants and birds. The project is part of a larger regeneration initiative called the ‘Eco-city Augustenborg’ which aimed to transform the neighbourhood into a socially, ecologically and economically sustainable settlement.
How does it work?
The open storm-water system has been created through a total of 6km of canals and water channels, as well as 10 retention ponds. These collect rainwater (flowing from roofs, roads and carparks) in natural ditches and reservoirs before directing it into a more conventional sewer system. Leading the water through this open system reduces the volume of water running off into the sewer system as some the flow of the water is slowed down, and some water remains in the open system. This helps to avert overflow and flooding. The landscape features (such as the ponds) were integrated into the townscape within 30 courtyard areas, which also created new green spaces for the local residents. As a result, there have since been no floods in the area.
A partnership between the Malmö housing company, Malmö water and city planners was a critical aspect of the project implementation. Technical expertise was required from each of these partners to ensure appropriate design, and funding of the project was also collaboratively provided. Further components of this successful partnership included stakeholder engagement, the presence of sophisticated technical expertise, and a high-level policy directive in support of experimentation. Understanding of the local ecosystems was not critical, but project designers had to possess a very detailed understanding of the frequency and severity of local floods.
Operation and maintenance
In the case of approaches like SuDS in Malmö, which involve changes to the urban landscape, it is key to engage all of the actors throughout the project, ensuring that all parties needs are considered in the process. In addition, it is important to secure sufficient financing before the project starts to cover the entire duration of the project, including for maintenance and monitoring activities after implementation is completed.
Obstacles and challenges
The core challenge was to develop a functional system that did not damage existing infrastructure and that was also acceptable to the residents. A lack of awareness about doubts about the value of the Sustainable Urban Drainage System created some resistance by city planners and water engineers. Apathy and language barriers also prevented citizens from fully engaging with and supporting the project, and it was found to be difficult to maintain enthusiasm and engagement with the community outside of structured consultation processes.
During the projects implementation, technical issues were faced including algal blooms, and finding space for the open storm-water system. For example, health and safety issues had to be addressed as parts of the drainage system were next to schools and/or elderly populations.
Revitalization of water elements Mestská zeleň Flood control measures Biodiverzita Povodně a přívalové srážky Nedostatek vody a sucho