Systems Analysis of Zaragoza Urban Water - SWITCH - Managing ...

Systems Analysis of Zaragoza UWS
Guillermo Penagos
There is a need of information tools that serve to evaluate this complexity and search for
alternatives that make the concept of sustainability fully operational for the Urban Water
System. Initial interest of researchers and decision makers in this regard was to produce
ad hoc Indicators for Sustainable Development (Lundin and Morrison, 2002)
A large number of indicators are used by water and waste water organizations to assess
their technical performance. Such indicators may differ between different organizations
and different countries. The results are large amounts of data, difficult to understand and
to interpret. Besides only few of those indicators have been developed to quantify
sustainability. There is still a need for a limited number of sustainability indicators for
urban water systems (Lundin, 1999).
One of the main problems of quantifying sustainability is the lack of a structured
methodology to develop indicators, with the consequent risk that such indicators would
be ineffective and, possibly detrimental in promoting sustainability objectives (Lundin
and Morrison, 2002). Therefore, recent studies have based on Systems Analysis
Approach and have used techniques related to the concept of industrial ecology, such as
Material Flow Analysis and Life Cycle Assessment. When properly followed, those
techniques have proven to be quite effective to evaluate environmental performance of
Urban Water Systems. Some authors have concluded that such techniques are needed
as a basis for all other studies concerning Urban Water Systems because the flows, the
major sources and the fate of water and its major constituents such as nutrients,
pathogens and harmful chemicals, must be clear for all alternative management
strategies (Ahlman, 2006; Benedetti et al., 2005; Lindqvist and Malmborg, 2004).
LCA analysis is suggested to be a comprehensive technique to assess environmental
sustainability of UWS. The term “Life cycle” referes to the major activities in the course of
a product lifespan from its manufacture, use and maintenance, to its final disposal,
including the raw material acquisition required to manufacture the product. Impacts
related to outputs will be emissions to different environmental compartments (Lundin and
Morrison, 2002).
The main advantage of LCA is that it can contribute to evaluate the impacts upon
different environmental compartments, preventing the implementation of management
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