The metropolitan area of Zürich is located in the Swiss midlands. In general, water is not a scarce resource, except at times of peak demand. Effective waste water treatment has been assured using advanced technology, but at a high financial cost. Now large investments are required to maintain the present facilities. Policy questions include:
  • How can a shift from supply to demand management be effected, to achieve cost-effectiveness and sustainability?
  • How is it possible to develop a predictive base for the response of consumer demand to increasing prices and different pricing regimes?
  • How can one improve the understanding of the rule-governed behaviour of managers in water supply and its importance in different institutional settings?
  • How will decreasing water demand affect the functioning of the current technological system to ensure a safe water supply and efficient waste water treatment?

3 main issues

  • How can the supply of water meet consumer demand in an economically and ecologically efficient way?
  • How can a shift from supply to demand management be effected?
  • What is an appropriate institutional design for urban water management to meet the challenges of the future?

map of zurich region

policy process in the region

The political responsibility lies with the municipal authorities of the city of Zurich. Water supply and waste water treatment are located in different departments. This is a certain problem if one considers the determination of water prices.

The main stakeholders are the management of urban water supply of the city of Zurich. They support the project and will be actively engaged in the development of the actor platform. The main clients are given by the owners of real estates. The individual households are not very well organized regarding the consumption of water. Most households pay a fixed sum per month to guarantee their water supply. Often this sum is included in the rent. Water prices are quite low and are irrelevant regarding the overall budget of a household. Because of these reasons most people are not aware of their personal water consumption.


characteristics of the environment related to water management

The metropolitan area of Zurich is located in the Swiss midlands. Water is in general not a scarce resource, due to the lake of Zurich which covers 66% of the city's water consumption. The rest of the demand is covered by groundwater (25%) and by spring water (9%).

Per capita water consumption is above the European level but it has been decreasing during the last ten years. Practices in water supply management have been based on the development of large capacities to meet water demand at peak times. The actual capacity lies at 500'000 m3 per day while peak demand in 1998 reached only 250'000 m3 per day.

An effective waste water treatment has been assured at a high technological level at large financial expenses. There are no pressing environmental problems regarding present water quality and supply. However, political authorities face an increasing dissatisfaction of citizens and NGOs with the strategy for technical end-of-pipe solutions to environmental problems.


major changes to happen in the next decades in the environmental and socio-econonomic boundary conditions

Urban water management is challenged by institutional change, new cost structures and new pricing regimes. Large investments are required to maintain the present facilities. This increases the uncertainties impinging on the current management. However, urban water management is quite inflexible being tied into a lock-in situation arising from a huge, long-lived and expensive infrastructure.

Regarding the environment one can expect another source of uncertainty given by a rise in peak demand due to a change in extreme weather events.

major uncertainties

The major uncertainties that have to be dealt with regard the change in peak demand due to a change in extreme weather events and the possible institutional changes.


questions that one would like to address with the model at the current state of knowledge about the region and stakeholders interests?

  • Simulate scenarios for the response of consumer demand to different pricing regimes.
  • Investigate the diffusion of water conservation technologies.
  • How will decreasing water demand affect the functioning of the current technological system to ensure a safe water supply and efficient waste water treatment?
  • Explore the effectiveness of different management strategies for a cost-effective and ecologically responsible management of water resources and a reliable operation of the water supply system in times of increasing uncertainty.
  • Investigate transition scenarios to other management and supply regimes with higher flexibility, higher economic and environmental performance.
  • Explore the potential of social learning in a participatory setting facilitated by such agent based models.


organization of the participatory process with specific reference to problem specification

An actor platform with about 10 participants will be set up. They will engage in a process of group model building and model moderation. This will comprise about 2 to 3 sessions with the platform as a whole and sessions with individual members. Currently we develop the method of model moderation further to be applicable for agent based modeling. We intend to investigate the mental models of the individual actors and include them as a major source of uncertainty into the models. The actor platform will accompany the process of model building. Finally the model will be validated in the participatory setting and scenarios for future water supply will be developed and discussed.

details of regional case studies

Available data set

    • Water consumption, water prices and financial data for the water supply of Zurich for the last 100 years.
    • Climate data (temperature, precipitation, etc.) for Zurich for the last 100 years
    • Broad demographic data sets for Zurich since 1914.
    • A first model is currently developed focusing on the rule-governed behaviour of engineers in water supply management. It is developed and applied in a participatory process with the board of managers of water supply in Zurich.
    • New approaches to model consumer behaviour are currently developed and implemented in a model.
    • A water demand calculator will be used to explore the potential of water conservation for households.
    • A study was undertaken to assess the market structure in water conservation technologies. Considerable knowledge about consumer demand and its dependence on technology, weather etc.


historical account about the major developments over the past decades

regulatory frameworks: The water supply of Zurich has been a public utility since its foundation in 1868. There have not been any changes in the regulatory frameworks during the last decades.

public perception: In public opinion water should be available in sufficient quantity with sufficient pressure at any time. This attitude led to the extension of the existing water extraction plants when peak demand reached 99% of the capacity in July 1976. Because of these extensions and decreasing water demand during the last decade we face large overcapacity today.

financial situation: Since 1986 the water supply of Zurich is financially independent. Thus it has to cover its costs by the income from the sale of water. In spite of decreasing water consumption the water supply managed to realize profit during the last years due to economies in different parts of the company.

environmental situation: Due to effective waste water treatment the lake has regained good water quality more than ten years ago. Different measures made sure that the quality of the groundwater and of the springwater could be kept on a high level as well.


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