Planning resilient water resources and communities: the need for a bottom-up systems approach

ABSTRACT

A robust understanding of water security, and the potential contributions made by alternative management strategies, is needed for a world challenged by population growth and climate-driven resource scarcity. This understanding is vital for realising our visions and plans to build future sustainable and resilient cities that have lesser impacts on increasingly scarce environmental and economic resources. The implications of making average demand assumptions on water security predictions and distribution patterns are investigated using calibrated bottom-up multi-scale numerical (Systems Framework) models of the Greater Melbourne and Sydney water networks and observed demand data. The calibrated Systems Framework models, which are highly spatially and temporally resolved, are progressively modified through erosion of the temporal and spatial granularity of their boundary conditions by replacing demands with various average assumptions. It is shown that average assumptions lead to material differences in model predictive behaviour, and that the directions of these differences are unpredictable and sometimes lead to counter-intuitive outcomes. It is concluded that the application of average assumptions of any kind is problematic (from both pure statistical and numerical modelling standpoints) and has the potential to heavily influence infrastructure investment and, more broadly, policy direction.

KEYWORDS:

• Water resource planning
• systems analysis
• bottom-up
• averaging
• water security
• resilience

Acknowledgments

The authors have contributed equally to this research project and gratefully acknowledge the contribution of the Journal editors and the anonymous reviewers for improving this discussion.

Additional information

Notes on contributors

Michael E Barry

Michael Barry is a Senior Principal Engineer at BMT and the Chair of BMT’s global Innovation Council. Michael has undergraduate honours and PhD degrees in environmental engineering from the University of Western Australia.  Michael also has an undergraduate Science degree in Physical and Inorganic Chemistry.  Michael has experience across a range of environmental engineering disciplines, including integrated urban water cycle management and water resource management, and one, two and three dimensional hydrodynamic and water quality modelling of natural and constructed water bodies.  Michael can relate modelling outcomes and processes to the development of policy governing basin scale water resources and associated water quality. Combined with information technology and numerical coding expertise, this background brings an experienced professional to basin scale water resources management.  Michael is a Fellow of Engineers Australia, and has RPEQ, NER and Chartered accreditation.

Peter J Coombes

Peter J. Coombes is a director of Urban Water Cycle Solutions is a Fellow of Engineers Australia and is currently an editor of the Urban Book of Australian Rainfall and Runoff. He recently contributed to inquiries into stormwater management held by the Senate of the Australian Parliament and Water Resources held by the Productivity Commission, and was a chief scientist in the Victorian Government. Peter has held senior academic positions at the University of Newcastle, Melbourne University and Swinburne University. He has experience in change processes in government and development of government policy. His professional and research interests include systems thinking and analysis, hydrology, water resources, economics, molecular sciences, water quality and public policy. More information can be found at http://urbanwatercyclesolutions.com