Agricultural
5 February, 2026
First audit conducted on Macquarie-Castlereagh groundwater
FIRST AUDIT ON NSW WATER RESOURCE PLANS
The independent Inspector-General of Water Compliance (IGWC), the Hon. Troy Grant has completed and published an 'Audit of Groundwater in the Macquarie-Castlereagh Alluvium'.
The audit is the first of its kind to be completed on one of NSW’s long-awaited Water Resource Plans (WRPs). The audit was commissioned to determine whether the NSW Department of Climate Change, Energy, the Environment and Water (NSW DCCEEW) and WaterNSW have implemented commitments made in the Macquarie-Castlereagh Alluvium WRP.
A failure to meet all commitments in a WRP has implications for compliance with environmental watering requirements in the Murray-Darling Basin Plan. This alluvium is comprised of six sustainable diversion limit (SDL) resource units with varying degrees of connectivity to surface water systems, and over twenty groundwater dependent woodland forests and wetlands including black box, lignum, river red gum and yellow box.
“The absence of accredited WRPs in NSW for many years was a significant issue for the Murray-Darling Basin Plan, and it was something in my role as Inspector-General that I raised publicly in 2022,” said Mr Grant.
There are 11 WRPs that apply to groundwater resources in NSW. While WRPs for two areas are still to be submitted with the Murray-Darling Basin Authority (MDBA) for approval, and one awaiting accreditation, eight have been accredited by the federal minister for the environment and water and are now operational.
What does this all mean to the community and environment? “There were some concerns about the sustainable management of this groundwater area as far back as 2020, before there was an Inspector-General with powers to hold water managers to account,” said Mr Grant. “In very dry conditions groundwater becomes more critical, because it is the last reliable source of water that allows ecosystems to survive, function, and recover from increasing climatic stress. Groundwater is also critical to human needs, especially for a city like Dubbo, and neighbouring towns of Coonamble, Narromine, Warren, Nyngan, Gilgandra, and Coonabarabran.”
The audit’s findings show that NSW has not met all commitments made in the Macquarie-Castlereagh Alluvium WRP. On a positive note, WaterNSW were fully compliant. This audit provides the public with visibility on the management of groundwater dependent ecosystems in the Macquarie-Castlereagh Alluvium WRP area and is an indication of progress toward achieving Basin Plan environmental objectives and outcomes. Failed commitments have implications for compliance with obligations in the Basin Plan for meeting environmental watering requirements in NSW for groundwater management.
“What I’m looking for across two separate and quite different audits, this being the first – the second to be completed, is evidence to show me that NSW agencies have fully implemented their obligations in the Basin Plan”, said Mr Grant. “I’m not quite there yet; I still need convincing.”
The Inspector-General has given NSW DCCEEW 90-days to provide details of any actions they propose to take if the audit recommendations are accepted. The IGWC will monitor the progress of actions that NSW DCCEEW have agreed to confirm once they have been fully implemented.
