A new ecological footprint calculation for the Australian water industry: regionalisation and inclusion of downstream impacts

A new calculation of the Ecological Footprint (EF) of a water provider addresses limitations in the previous methodology by regionalising a previously national input-output model, and determining the area of disturbance caused by environmental toxicants not considered in the traditional EF model. In a first step, the regional input-output model determines indirect effects of water services activities in the form of point sources of pollutants. Accuracy is improved by hybridisation using process data to account for the direct environmental burden of the water service. The accuracy of the input-output model is improved by reconciling data sources; calibrating concordance tables and employing optimisation techniques to deal with conflicting data sources. The second step involves a nested fate model, which follows the fate of the point source emissions at several spatial scales. The final output provides an indication of the direct and indirect burden connected with the water business, throughout its entire upstream supply chains. This proposed EF methodology improves on previous EF methodologies by avoiding exclusive reliance on national average data, and by including toxicants in a disturbance-based calculation analogous to the established inclusion of greenhouse gases in EF, making it more comprehensive. It is hoped that the additional detail and comprehensiveness will make the new method a more effective environmental reporting and communications tool for the Australian water industry. This generic approach to environmental reporting may potentially be applied to other economic activities