An Ecosystem Health Assessment of Constructed Urban Lakes
Many existing urban lakes are considered to be in a degraded state which impairs their ability to fulfil all but the most basic of functions (e.g. storage). The causes of urban lake degradation are well understood to be linked to poor design, poor quality of inflow, and the attributes of urbanised catchments (e.g. impervious area and directly connected drainage infrastructure). While the reasons for urban lake degradation are well understood, the approach to assessing and managing urban lakes has failed to adequately characterise them for what they are: dynamic, integrated ecosystems. Urban lake assessments are typically limited to measuring physicochemical indicators in a static state, which presents a fragmented, mono-disciplinary, incomplete measurement of lake health. This approach makes frequent use of short-term solutions (e.g. macrophyte harvesting) and is largely reactive. Management essentially requires a system to fail in the eyes of stakeholders before intervention occurs. This does not consider an urban lake holistically as an ecosystem, as the links between biotic and abiotic factors are not realised. This approach also ignores the local community as a component of the urban lake ecosystem, despite the inevitable interaction between the community and lake.
Submitted in the fulfilment of the requirements of the degree of Doctor of Philosophy, University of the Sunshine Coast, 2012.