EDO water law specialist Emma Carmody has co-authored an article published today which finds that the Australian Government’s $4 billion irrigation efficiency program for the Murray-Darling Basin (MDB) has led to irrigators who received infrastructure subsidies extracting up to 28 per cent more water than those who did not.

Dr Carmody and water management experts from UNSW, the University of Adelaide and Australian National University (ANU) examined the impact of taxpayer-funded irrigation infrastructure upgrades on water extractions and environmental water recovery in the MDB.

Their findings – which are particularly relevant in the northern Basin – reveal multiple gaps in the regulatory framework which could lead to undetected breaches of catchment-level extraction limits.

This raises serious doubts about the true extent to which environmental flows are increasing at a catchment and basin scale as a result of irrigation infrastructure upgrades.

EDO Special Counsel Emma Carmody has led EDO’s work for communities along the Basin over several years and was an expert witness at the South Australian Royal Commission into the MDB Plan. She said:

“Our findings cast uncertainty on the long-term sustainability of the Basin’s rivers and the communities which rely on these flows for their livelihood. The health of rivers and groundwater systems in the MDB will continue to degrade unless these problems are addressed.”

“We simply cannot afford to be cavalier about water measurement and compliance with catchment-wide limits on extraction. The latest climate modelling by the CSIRO indicates that water availability in the MDB could decrease by as much as 40% within the next three decades.”

“Until we have ‘no meter no pump’ laws across the Basin, we will be plagued with uncertainty about how much water is actually being taken out of our rivers and aquifers,”, said Dr Carmody.

“There are a range of regulatory and governance deficiencies which could result in the increased extraction of water from some rivers and aquifers in the MDB beyond specified limits. These include illegal extractions, absent or inaccurate measurement of extractions, increased floodplain harvesting, groundwater substitution and problems with ‘sustainable diversion limit’ compliance tools in some catchments.”

“The greater the level of uncertainty around the volume of water being extracted, the greater the likelihood that statutory limits will be exceeded – and that these exceedances will not be detected,” Dr Emma Carmody said.

“We hope that the government will consider our findings an opportunity to continue developing and implementing accurate measurement of all forms of water extractions and transparent, fully audited water accounting across the MDB.

“We also need to ensure that compliance agencies are independent, properly resourced and have a mandate to enforce the law.”


The research findings, published in the international journal Resources, Conservation and Recycling, analysed almost 2500 on-farm MDB irrigation surveys and identified a “rebound effect” of increased water extractions.

These findings are consistent with similar studies in river basins all over the world.

However, the MDB – unlike most other river basins – is subject to a “cap and trade” system which is intended to ensure water extractions stay within statutory limits. It is therefore commonly assumed that the “rebound effect” is limited to farm level increases in water extractions and does not increase water extractions at the catchment or basin scale.

The authors sought to interrogate this assumption by analysing a wide range of laws, policies, literature and data. This included analysing whether compliance tools (in particular, hydrological models) were likely to accurately assess compliance with catchment-level limits on extraction. 

Their study – particularly relevant in the northern Basin – reveals multiple gaps in the regulatory framework which could lead to undetected breaches of catchment-level extraction limits.