Semizentral – Infrastructure systems for cities of the future experiencing rapid growth

Ver- und Entsorgungsanlage/Semicentral freshwater supply and wastewater treatment plant in Qingdao/China (copyright: Cosalux)

Within the CLIENT joint project “Semizentral: Resource-efficient and flexible supply and waste disposal infrastructure systems for rapidly growing cities of the future – Phase 2” ISOE is supporting the implementation of a project that is testing the semicentral freshwater supply and wastewater treatment in a new district of Qingdao/China.

Research approach

Based on the current situation in the new district, ISOE develops a scientific material flow model of the semicentral concept: After defining the boundaries of the system, the individual water and wastewater flows are recorded based on their amounts and compositions and are then transferred into a material flow model. This allows simulation of the source-separated flows which differ from those in conventional infrastructure systems: Not only is drinking water made available, but also service water which can be used for other purposes (e.g. for flushing toilets). Wastewater from the showers and sinks is collected and treated separately from the more polluted wastewater from the toilets and kitchens. The model also allows diurnal changes and fluctuations in the flow of material to be depicted and analyzed in order to compare them with the water and wastewater flows of conventional infrastructure solutions. The model allows analyzing vulnerabilities and risks by, for example, simulating hydraulic fluctuations, extreme weather events or possible breakdowns, i.e. all the hotels in the region being vacant. These analyses do not only factor in the material flow model, but also other aspects such as social costs.


More than half the world’s population now lives in cities and the number is growing by about a million a week. Many of the rapidly-growing cities in emerging and developing countries suffer from water scarcity. In many places, people’s basic water supply is already at risk or cannot be guaranteed. And the situation for sanitation is even worse, with the correct disposal of wastewater contaminated by pathogens often also posing a problem. So there is a pressing need for action. What is needed are sustainable approaches to the supply of water and sanitary services, wastewater disposal, waste management, and settlement and infrastructure planning. A complicating factor is that conventional supply and disposal systems now commonly used in developed countries have the disadvantage that they focus only on one single task – for example the disposal of wastewater. This is where the project “China Semizentral” comes in which is now being tested in the northern Chinese port city of Qingdao. A new district for 12,000 people is currently being built here for the World Horticultural Exhibition 2014. In order to prevent what is happening in many large Chinese cities, in Qingdao a semicentralized water infrastructure system is build, meaning smaller-scale supply and disposal structures which can flexibly adapt to population growth by “growing along”. In addition, source-separated wastewater flows are differentiated according to their degree of pollution and are treated for reuse.

Project partners

  • Technical University Darmstadt, IWAR Institute, Wastewater Technology Department, Institute of Geodesy, Department of Land Management, Department of Architecture, Department of Design and Urban Development and Department of Construction
  • Cosalux, Offenbach/Germany
  • Far Eastern mbH, Ludwigshafen/Germany
  • Gebr. Heyl Vertriebsgesellschaft, Hildesheim/Germany
  • Gummersbach Environment Computing Center, FH Cologne/Germany
  • Kocks Consult GMBH, Koblenz/Germany
  • Endress+Hauser Conducta, Gerlingen/Germany
  • Roediger Vakuum, Hanau/Germany
  • Emscher Wassertechnik, Essen/Germany
  • m+p consulting, Munich/Germany


Semizentral is being funded within the BMBF funding measure CLIENT of the “Research for Sustainability (FONA)” funding program.


Schramm, Engelbert/Martina Winker/Martin Zimmermann (2020): Gutes Management hilft, Fehlanschlüsse zu vermeiden. bbr Leitungsbau Brunnenbau Geometrie 71 (12), 22-27

Zimmermann, Martin/Engelbert Schramm/Björn Ebert/Christoph Meyer/Martina Winker (2020): Bewertung von Handlungsoptionen zur Minimierung von Fehlanschlüssen. Am Beispiel eines semizentralen Wasserver- und -entsorgungssystems in Qingdao, China. gwf-Wasser/Abwasser 161 (5), 68-76

Schramm, Engelbert/Björn Ebert/Bingxiang Wang/Martina Winker/Martin Zimmermann (2019): Keeping Flows Separate: Good Management Practices in Novel Urban Water Systems Derived from Error Analyses. Water 11 (12), 2597

Ebert, Björn/Engelbert Schramm/Bingxiang Wang/Martina Winker (2019): Governance instruments for optimising source separation in novel urban water systems: the case of cross-connections in urban water systems.Water Policy 21 (2), 412-427

Zimmermann, Martin/Martina Winker/Engelbert Schramm (2017): Die Vulnerabilität von Wasserinfrastrukturen. Transforming Cities (4), 48-53

Birzle-Harder, Barbara/Konrad Götz (2016): Wahrnehmung von neuartigen Wasserinfrastrukturen und Wassernutzung in der chinesischen Stadt Qingdao. Ergebnisse einer qualitativen empirischen Studie zur Wasserkultur im Rahmen des Projekts SEMIZENTRAL. ISOE-Materialien Soziale Ökologie, 48. Frankfurt am Main: ISOE - Institut für sozial-ökologische Forschung

Cheng, Yuanting/Konrad Götz (2016): Elemente der Wasserkultur in der chinesischen Region Qingdao. Eine Recherche im Rahmen des Projekts SEMIZENTRAL. ISOE-Materialien Soziale Ökologie, 47. Frankfurt am Main: ISOE - Institut für sozial-ökologische Forschung


2013/06 – 2017/12