City Water Balance (CWB)
The City Water Balance (CWB) tool was produced as part of the SWITCH project in 2006-2011, which was funded by the European Commission to improve sustainable urban water management. CWB is designed as a scoping model, which can be used to explore the impacts associated with a wide range of potential urban water management scenarios. It provides information about water demand, water quality, energy consumption and life-cycle cost.
CWB uses simplified representations of the flows and stores of water and energy across a city, at a daily time-step in order to predict changes over annual or decadal periods. The model is relatively quick and easy to use as it incorporates existing spatial datasets and pre-defined attributes for land uses and water management technologies. Unlike some other urban water models, CWB closely considers natural systems in the model, for example, groundwater and surface water bodies are spatially articulated. The CWB tool was applied to the city of Birmingham, using historical data for verification and validation of the model. More information can be found in a PhD thesis, written by Ewan Last in 2010, as well as a number of other papers (see links below).
Information on SWITCH website – http://www.switchurbanwater.eu/res_software.php