I interviewed Mike Young, the Professor of Water Economics and Management at the University of Adelaide on 11 March about his recent discussion paper titled “A future-proofed Basin: A new water management regime for the Murray-Darling Basin“.

The Murray-Darling Basin in Australia is over one million square kilometres in area, and provides water to the majority (70%) of Australia’s irrigated agriculture (1.4 million hectares). It’s management is complicated because the Basin extends over five states and one territory. Until recently, the Basin was managed under a joint agreement – called the Murray Darling Basin Agreement. 41 per cent of Australia’s gross value of agricultural production (1992) is produced in this region. It is also an important water supply for many rural towns, and the capital city of the state of South Australia – Adelaide, the city I live in. The two main tributaries are the Darling River in the north and the Murray River in the south.

The Rivers of the Murray Darling Basin are under terrible stress. The largest state in the Basin, NSW, has taken more than its share of water that all the states agreed to (called “The Cap”). All states do not meter all water use, and more water is extracted from the river systems than is agreed under the Cap. Since irrigation began in the Basin in the 1800’s, salinity has been a problem, as water that moves into the groundwater collects salt and then flows back into the River. The response to this increased salt load into the River has been to build salt interception schemes along the rivers which intercept salty groundwater before it reaches the rivers. Nevertheless, the river floodplain has become increasingly salinised, killing trees and wetlands. The River has been under significant stress of reduced flows and salinity for some time. In the year 2000, a series of drought years created a major crisis for the River. All of the storage dams along the river are now at low levels. The River stopped flowing at its mouth, putting the Ramsar listed Coorong estuary in mortal danger. In 2008, the large Lower Lakes at the bottom of the river are drying up, and only a series of barrages stops the sea water backflowing into these freshwater lakes and back up the river. Irrigators do not have access to secure supplies of water, and are under huge financial stress or have left the land, leaving orchards and other crops to die. Wetlands have dried up and the floodplain of the lower reaches of the river are white with salt. The Coorong estuary has almost completely changed character, from an estuarine environment to a hypersaline system of low diversity. Some birds species are at imminent risk of extinction in this region.

The original Murray Darling Agreement has collapsed, and the management of the River is now undertaken through a series of management meetings, which must seem like crisis meetings, by a group of senior bureaucrats called the “Senior Officials Group”. Every month the news gets worse as the drought continues. The Lower Lakes of the Murray River are so dry, they are now at risk of developing acid sulphate soils. If the drought continues, the salinity of the River will continue to increase more rapidly. The security of water to the city of Adelaide, with a population of over one million people, is at risk.

If this is a harbinger of climate change, then the Basin cannot continue to be managed as it was in the past. The results of this management system is system collapse in dry periods.

In my interview with Mike Young, he proposes a new model for managing the Basin. He argues for a different management system that is much more resilient to long periods of drought, for which there is a higher risk under climate change. The essence of the changes are:

1. Replace the current entitlement and allocation regime with a robust one that can be confidently explained as one that will work no matter what the climate scenarios in the future

2. Implement the resultant change in a just a fair manner.

I am not going to repeat the article that Mike wrote. He is much better than I at presenting his arguments. I would encourage you to read his full article (link above) and listen to the podcast.

Written by Paul Dalby. For more information – http://www.litfuse.com.au

Feed – http://feeds.lifuse.com.au/litfuse