The challenge of system change : an historical analysis of Sydneyââ"šÂ¬Ã¢"žÂ¢s sewer systems

Despite the obvious health benefits of the sanitary revolution and construction of sewered systems, there are increasing doubts about the long term sustainability of centralised, water-based sanitation. Growing uncertainties such as rapid population growth, emergence of new pollutants, changing hydrological conditions in relation to climate change and global economic instability will require systems to be more open to ââ"šÂ¬Ã‹Å“flexible and reflexive approachesââ"šÂ¬Ã¢"žÂ¢ in meeting future sanitation needs. The highly inflexible nature of existing sanitation systems burdened with over a century of capital infrastructure investment and assets that require 30-50 years to pay back, make centralised sanitation both economically unsustainable and institutionally rigid. Social practices associated with water-borne sanitation have been embedded within western society for over a century making ââ"šÂ¬Ã‹Å“radicalââ"šÂ¬Ã¢"žÂ¢ system change and the introduction of alternative technologies and habits of practice challenging. Change therefore cannot be brought about through technological innovations alone; it requires mutually reinforcing institutional and socio-cultural transformations. This has important implications for the relation between design and technological innovation. Design can be understood as a practice involving the deliberate planning of socio-technical change, yet the relational dynamics of change have not traditionally played a part in design biased toward a ââ"šÂ¬Ã‹Å“technological fixââ"šÂ¬Ã¢"žÂ¢.