International Conference on Sustainable Built Environment (ICSBE-2010) Kandy, 13-14 December 2010 INTEGRATED LAND USE AND MULTIPLE WATER SUPPLY-DEMAND MODELLING FRAMEWORK: A PERI-URBAN CASE STUDY B. Nawarathna 1 , H. Malano 1 , B. Davidson 2 and B. Maheshwari 3 (1) Department of Civil & Environmental Engineering, The University of Melbourne, VIC 3010, Australia email: bnaw@unimelb.edu.au, PH (+614) 3330-1941. (2) Department of Resource Management, The University of Melbourne, VIC 3010, Australia. (3) School of Natural Sciences, University of Western Sydney, Sydney, NSW 1797, Australia. Abstract: The South Creek catchment with an area 620 km 2 confronts increased competition between potable water, irrigation and environmental flows. Peri-urban areas also generate a large volume of effluent and stormwater and can often meet some or all the irrigation and industrial water needs provided adequate infrastructure is available. An adequate harmonisation of these multiple supplies and land use using a total system analysis approach leads to a better understanding and evaluation of the limitation and opportunities to enhance the overall performance of the system. This paper descriers the developed modelling framework to simulate water supplies and forecast future demands and integrate supplies and demands in finding water allocations with different climate change and land use scenarios. The integrated model is applied to the South Creek catchment to plan future land use and water supply in an environment of water scarcity under system harmonisation water resources management concept. Keywords: System Harmonisation, Peri-Urban Catchment, South Creek catchment, Water Resources Modelling 1 Introduction Research and development in water resources management usually involves separate investigations into technical, institutional, environmental, and social spheres; however, with a primary focus on technical aspects. Hard-engineering solutions were implemented without focusing on overall economic and environmental impacts, or the social implications associated with these projects (Spingate-Baginski et al., 2003). With increasing sustainability discourse, there is a realization that the technical aspects of water resources management need to be addressed with the immediate understanding of environmental and social interactions for successful development and application of potential solutions. Through this research, an attempt has been made to develop an alternative to past approaches for achieving more effective, equitable and efficient water resources management in heavily stressed catchments such as Western Sydney’s South Creek Catchment. Different demand management options were explored from a multi-disciplinary perspective through a concept known as ‘System Harmonisation’. System Harmonisation involves addressing the hydrological and economic impacts arising from alternative planning and management decisions, as well as identifying and including all affected social, cultural, institutional and policy issues to maximise benefits across the system. Development and management of catchments require the utmost cooperation between all stakeholders involved, be it a single urban dweller, a farmer, government, corporate or academic (Prato & Gamini, 2007). The main aim of this research is to develop a dynamic generic tool for integrated water resources planning and strategy development in peri-urban landscapes using water resources and economic principles assessed from a social perspective. The tool is adaptable across peri -urban Australia and beyond. The study area has been scheduled for significant land use change due to future development, where a rapid and substantial increase in urbanized areas will be seen; however, maintenance of water supply for existing farmlands, industry, recreation, and environmental services has been highlighted as integral for sustainability of this catchment.