Source (public version) is a limited functionality version of eWater Source – Australia's national hydrological modelling platform. It is designed to simulate all aspects of water resource systems to support Integrated Water Resource Management (IWRM) studies in urban, catchments and river basins including human and ecological influences. eWater Source is Australia’s national hydrological modelling platform which integrates water resource assessment with policy. An adaptive customisable platform which enables the technical assessment of water balance is combined with a unique governance modelling capability to produce water accounts and operate rivers according to agreements and treaties. A new generation tool created to support the transformation of Australia’s water modelling capability, Source is the outcome of two decades of collaboration between State and Federal Government water organisations, leading universities, water utilities and regional rural water authorities through the eWater CRC and it’s predecessors the CRC for Catchment Hydrology and the CRC for Freshwater Ecology. Endorsed and defensible – Source has been endorsed by the Council of Australian Governments as the national hydrological modelling platform. Source (public version) is limited to 20 nodes.

Hydrological analysis for equitable sharing and operational management of scarce water resources Source(public version) does not contain the water management and governance capabilities of the full version of Source, Australia’s national hydrologic modelling platform, but can be applied as a sectoral water balance tool which forms the basis of development and testing of transboundary IWRM water governance approaches in the full version.

Source (public version) is ideal for students and water modellers wishing to explore the potential of the full Source modelling platform. Source is designed for managers, researchers, modellers and consultants to develop computer simulation models of rivers and catchments so as to firstly, understand and explore important aspects of their behaviour and secondly, guide decision making. To use Source, you should have a good working knowledge of catchment hydrology, integrated catchment modelling, river systems and river system modelling and, preferably, the support of experienced users. This reference manual assumes you have a basic knowledge of mathematics, physics and chemistry equivalent to completing high school or introductory tertiary courses. Information produced by Source may be useful for a broader audience of people, including: Management and government representatives who want to understand how and where model results were obtained; Clients, such as resource managers (of catchments or water), water planners and operators, who rely on a model’s results but are not necessarily interested in the detail of the model development process. They are often, however, interested in understanding general configuration and application issues; People affected by decisions supported by model results or who have a general interest in water use in a river system (eg irrigators or environmental groups); and People with an interest in water science, who may use model results and want to understand the model’s behaviour.

Source provides a flexible structure that allows you to select a level of model complexity appropriate to the problem at hand and within any constraints imposed by your available data and knowledge. Source allows for scalable solutions to be developed and address the impact that uncertainties in models and inputs have on the outcomes. Source expresses the ‘Adaptive Complexity’ principle where data, models and outcomes have to be considered when designing a modelling approach as articulated in the eWater Best Practice Modelling Guidelines.

Source is not a single hydrological model. It is a range of models and tools that have been incorporated into a single flexible adaptable environment that recognises the practical political and technical issues in developing water policy and the need for transparency and sustainability. It can easily be customised by users to address specific local problems, or can be pre-configured for typical IWRM situations.

Source operates through a high-level graphical interface, more like a manager’s “workbench” or “dashboard” than a traditional hydrologic or hydraulic model. The interface is deceptively simple as it begins with a schematic view of the watershed or river which is built by dragging icons from a palette to create a conceptual view. At this high level scale, simple computational engines can be used to quickly and easily explore with stakeholders the practical way a river basin operates, without significant data requirements. Rainfall-runoff models, pollutant export models, sediment/nutrient retention (filter) models, link routing models, link decay models, nodal process models , are all selected from a wide range of alternatives and can be assigned globally or by individual computational unit within the entire model domain. For example many standard rainfall-runoff models have been incorporated into the code already and each sub-catchment can use a different model if so desired.

eWater Source is the definitive integrated water resource management (IWRM) modelling software for: • integrated water resource assessments, including agricultural, hydropower, urban, industrial and environmental requirements • water balance studies from catchment to river basin scale • water accounting and analysis of supply/demand balances • inflow forecasting and multi- objective reservoir operations • resource assessment and allocation policy development and planning • trade-off analysis to balance sharing and equitable use of scarce water resources • low flow and drought management • water quality analysis based on catchment land use scenarios • impacts of climate change and transboundary transfers • bulk water systems optimisation, planning and operations including multiple supply options (reservoir/recycling/desal) • conjunctive groundwater-surface water use analysis. For more applications see: eWater Case Studies

Rainfall Runoff Models Storages and Reservoirs *Water Users and Demands *Water Quality *Groundwater *In stream Routing *River and Reservoir Operations