Provision of usable projections of future water availability for southeastern Australia: The South Eastern Australian Climate Initiative

Abstract

Projections of future water availability are required by water managers and policy makers in order to take action to mitigate some of the potentially negative impacts of climate change on water supplies in the urban, agricultural and environmental sectors. However, in order to do this, these projections must have some level of confidence associated with them, and even if this is the case, the research community must make the data and/or information available in a format that is directly usable by water managers and policy makers. This paper presents results from a water availability study recently carried out across southeastern Australia as part of the South Eastern Australian Climate Initiative. More importantly, it shows how the results of this study have been used in defining a range of plausible future streamflow scenarios to be used by water resource managers in the state of Victoria in updating its water supply-demand strategies for the next 50 years. Climate change projections for this region were summarised by creating “dry”, “wet” and “median” future runoff scenarios for 2030 and 2060 based on the second driest, second wettest and median global climate model (GCM) results. These results were then averaged across 27 catchments covering the state of Victoria. We contend that in areas such as the state of Victoria where there is near-unanimous agreement among GCMs as to the direction of climate change impacts on rainfall, along with theoretical understanding consistent with changes in large scale circulation in a warmer world, projected changes in water availability can be used by water resource planners to assist them in better planning for future changes in supply.

Keywords:

• Runoff
• climate change
• southeast Australia
• water availability

Additional information

Notes on contributors

D A Post

Dr David Post is a Principal Research Scientist with CSIRO Land and Water in Canberra. David has carried out research on most aspects of the hydrological cycle, starting with atmospheric chemistry at the University of Newcastle, NSW, oceanography at CSIRO Atmospheric Research, then onto hydrology at the Australian National University, ACT, Oregon State University, USA, and now CSIRO Land and Water. David led the Tasmania Sustainable Yields Project and was the Program Director of the South Eastern Australian Climate Initiative, on which the current paper is based. He is currently Projects Director for the Bioregional Assessment Program.

R J Moran

Rae Moran has been involved for over 35 years as a hydrologist in the field of water resources planning and management. She has a MA (Hons) from the University of Canterbury in New Zealand and a MEngSc from Monash University. She was initially involved in forest hydrology research with the former Melbourne and Metropolitan Board of Works, moved to the Victorian Department of Water Resources in the mid-1980s and remained with the Department in its various incarnations until her retirement in early 2013 from her position as the Senior Hydrologist in the Water Group, Department of Environment and Primary Industries. During her time with the Department Rae was involved in a variety of roles focused on improving the understanding and management of various short-and long-term risks to the availability of water resources across the state, in particular climate variability and climate change and land use change.