Towards Solar Decathlon: Concepts for a Sustainable Urban Water Management in a new eco-district

Water is rarely considered to be a crucial aspect in sustainable housing. In fact, water sustainability in eco-districts and in ecological architecture is frequently limited to recycling and reuse solutions. Why less water? What could explain the choice of an installation, of a specific strategy or of a criterion trying to decrease water needs? Terms as ecological footprint or sustainability are becoming more and more used, however, how can sustainability be measured? What does sustainable water mean? What are the parameters that quantify the ecological footprint of a water management system? Within this project, some possible concepts of optimization and valorization of sustainable urban water system have been defined and explored. Numerous studies about water management, water distribution, sanitary technologies, recycling, etc. have already been done. Nevertheless, it is less common to identify the reasons that are able to justify a reduced consumption of water. Eco-district labels propose several solutions for sustainable water, however they are limited by scale or simply focused on one stage of the water cycle. The aim of this project is then to consider water from a larger point of view: through a Life Cycle Analysis approach, needs and properties of different urban water management systems are compared and evaluated. The scale considered for such reflections is effectively a central parameter; in this case, hypothesis will be applied to collective habitations inserted in a district and part of a specific urban context: the city of Fribourg. The urban environment has particular features in relation to surrounding rural areas: energy exchanges, hydrology characteristics and limited ecosystems. The relationship between the use of natural resources and urban development is becoming more and more important; the purpose of this thesis is then to define a methodology able to suggest a sustainable use of water through environmental, political and economic issues. A real urban case study with its current water management system defines what has to be analyzed and allows evaluating the limits and the possible enhancements of such system. Thus, in order to have an idea about the potential of sustainable water management solutions, an ambitious analysis of energy related to water uses and disposals is created and is used to show the reasons for change in a real model as the city of Fribourg. A comparison between two extreme scenarios of Fribourg’s selected zones is finally developed, discussed and implied in the conclusions through specific actions and facts. The results show that a high potential of improvements exist. Using them to elaborate new strategies in collaboration with the several stakeholders contacted may contribute to achieve many of today’s objectives for a sustainable urban water management. The best scenario, chosen with a new concept of eco-label, summarizes and concludes the analysis.