Project background and research context

Functioning ecosystems and the services they provide form the basis for sustainable societal development. However, the performance of ecosystems is being affected by numerous anthropogenic factors, such as: climate change, biodiversity loss, land-use changes, and urbanization. Urbanization, as a complex societal action, has a particularly pronounced impact on the natural water and energy balance, both in the urban space itself as well as in the surrounding city and natural environments. Urban societies are heavily dependent on functioning ecosystems, which are intertwined with their technical infrastructures. Water plays a crucial role here in the maintenance of this complex relationship. It serves as a vital energy resource and pollutant sink for societies, while also serving as a habitat and environmental medium in nature. Without clean water, the functionality of important ecosystems is put under threat.

The work of the junior research group SEE-URBAN-WATER focuses on the interaction of technical infrastructure systems and urban ecosystems, as well as the role of the urban environment in this relationship in developing countries. The following research questions are addressed inter- and transdisciplinary using case studies in Nicaragua and Costa Rica:

  • How do urban drainage systems interact with the natural water cycle and ecosystems connected by river systems?
  • To what extent is urban wastewater disposal based on natural ecosystem functions possible (targeted use of ecohydrological processes as a coupled urban-natural system)?
  • How can engineering planning methods be combined with socio-ecological considerations?
  • What changes in power politics require a transition from traditional urban drainage concepts to near-natural solutions?

Research approach

The Pochote River located in León (Nicaragua), and the Quebrada Seca- Río Burío River located in Heredia (Costa Rica) are used as case studies in order to develop, test and study the effects of ecological urban drainage and wastewater treatment infrastructures. Cooperation for the research is coming from relevant partners from science, administration and society within the study areas. Investigations are being carried out at representative locations, which should provide transferable knowledge to other areas and water bodies. While nature-based solutions for wastewater and rainwater collection and treatment of water bodies are being tested in urban areas and in urban water bodies, the impact of these measures on the provision of ecosystem services and the absorption capacity of near-natural water ecosystems is to be investigated in the larger river basin. This allows the research group to assess the extended benefits of nature-based infrastructures by examining the effects of the urban area on the river basin. Technological solutions are to be supplemented by socio-ecological and environmental-economic benefit analyses for the environment and society.

Objectives and expected results

The overall project objective is to develop the basis for a sustainable social-ecological transformation process by developing and testing nature-based urban drainage and wastewater treatment infrastructures. In particular, the integration of application knowledge across technological, ecological, and socio-economic measures is intended to initiate a process of co-designing such a transformation with the society. The expected results can be used for the improvement of public services such as urban drainage, wastewater treatment, water protection, and disaster control. The knowledge generated by this project should also prove useful to and for city administrators, water supply and sanitation companies, government officials for environment and health offices, the management of the river basis, as well as for other regions and public institutions.