The steady increase of urban population and the possible onset of climate change that may adversely affect the amount of water available in current water supply systems, makes the study of stormwater and rainwater harvesting and wastewater recycling a high priority. The basic proposition is that any system of water supply that can reduce the amount of water drawn from main reservoirs will be of benefit to the whole supply region especially in terms of drought security. This paper describes a versatile modelling framework which can simulate a wide variety of combinations of centralised and decentralised Integrated Urban Water Management schemes from the allotment to the estate scale. The framework combines two modelling approaches. The first, called urbanCycle, simulates water supply, stormwater and wastewater using allotments as the basic building block. Although urbanCycle can simulate processes in great detail, it assumes that the network forms a directed acyclic graph. This simplifies the connectivity logic but precludes investigation of systems with decentralized storage, feedbacks and multiple supply paths. To overcome this, a second model, based on network linear programming, is embedded in the urbanCycle framework to enable the modelling of recycling and harvesting options, as well as on-the-fly supply and demand decision making, based on objectives rather than pre-set operating rules.
32nd Hydrology and Water Resources Symposium (H2009). H2009: Proceedings of H2009, the 32nd Hydrology and Water Resources Symposium (Newcastle, N.S.W. 30 November - 3 December, 2009) p. 865-876