Assessing water use and reuse options - a holistic analysis of a Model City, coupling dynamic system modelling with Life Cycle Assessment

A dynamic model, fed with time-variant inputs, of the entire water urban system, coupled with Life Cycle Assessment (LCA) and Life Cycle Costing (LCC), was developed and applied to perform water balance analysis and to assess the environmental and economic aspects of water reuse. Six scenarios using different water sources potable water, rainwater, greywater, and treated wastewater were compared for a future Model City under typical Israeli conditions. The integrated dynamic simulation-LCA-LCC approach considers demands for several water resources and their availability, contains several feedback loops in the water system, and can be applied to any case study. Finally, the combined simulation-LCA-LCC was embedded into an optimisation framework. Results indicate that using treated greywater or treated wastewater for non-potable uses were the most economical scenarios. Business-as-usual scenario, where all urban water functions use potable water, displays the largest negative environmental impacts in all categories compared to using alternative water sources.