Urban water quality and the Triple Bottom Line - Can we reconcile the irreconcilables? (original) (raw)

2003, Faculty of Built Environment and Engineering

The adoption of a triple-bottom line approach is advocated to safeguard urban water quality. Ecosystem functions need to be addressed initially followed by social and then economic needs. This calls for a cultural change towards urban water resources rather than the current piecemeal approach. Water and water environments are valuable community assets. Urban land use coupled with anthropogenic activities alters the stream flow regime and degrade water quality. Urban water pollution is difficult to cost in terms on conventional monetary measures. True costs extend beyond immediate human or the physical boundaries of the urban area and affect the function of surrounding ecosystems. Current approaches to safeguard water quality are largely ineffective. They are generally based either on, insufficient design knowledge, faulty value judgements or inadequate consideration of life cycle costs. The problem of urban water pollution can only be remedied through innovative planning and the courage to implement sustainable practices. Status quo Water environments are greatly valued in urban areas as ecological and aesthetic assets. However, it is the water environment that is most adversely affected by urbanisation. Land use modifications associated with urbanisation are invariably reflected in the stream flow regime such as increased volume and peaks. Additionally, anthropogenic activities introduce numerous pollutants to the environment that are eventually conveyed to receiving waters. The deterioration of water quality, degradation of the stream habitats and flooding, are the most tangible of the detrimental impacts of urban stormwater runoff.