Reasonable excuse FAQs

Aerial view of the Murray Darling Junction in Wentworth, NSW.

The Murray Darling Basin Authority (MDBA) has rejected the department’s claim for reasonable excuse for going over its Sustainable Diversion Limit (SDL) in the Barwon Darling. The MDBA sets a limit on the volume of water that can be extracted from each SDL unit in NSW. Simply put, the SDL is the long-term average of how much water can be taken out of that area. Under the Basin Plan each state is allowed to submit a reasonable excuse for why they exceeded the annual permitted take.

A public webinar was held on Wednesday, 4 August at 5 pm to provide further information and answer questions from the public.


How much did the actual take exceed the permitted take?

For 2019-20 in the Barwon Darling, the annual actual take (AAT) exceeded the annual permitted take (APT) by 57.7 gigalitres (32%).

Was more water taken than is allowed?

It is important to note that, to the department’s knowledge, no water user took more than they were entitled to under the water sharing plan or their licence conditions. Individual water user compliance is an issue for NRAR.

Access to water in the Barwon Darling depends on flows in the river reaching commence to pump levels. If no other restrictions are in place, such as s324 orders, licence holders can extract up to their individual usage limits of 300% of entitlement for the year, provided there is sufficient water in their individual water allocation accounts.

With little or no opportunity to extract water in the previous two years because of ongoing severe drought, water accounts had significant water held in accounts. When restrictions were lifted and subsequent flows reached commence to pump levels late in the 2019-20 water year, many licence holders legally pumped up to or near their individual 300% usage limit for the water year and filled on-farm water storages for later irrigation use.

Will this affect other water users?

As the non-compliance was the result of a technical issue with the modelling and to the best of our knowledge no water users took more water than they were entitled to, there was no impact to water users downstream. There was no impact on environmental water holdings.

What was our reasonable excuse?

Our claim for reasonable excuse is based on a change to the modelling that impacted the calculations of the annual permitted take. In addition, the introduction of new meters resulted in inconsistencies in actual versus forecast usage.

Critically, water users on the Barwon Darling were able to, while following WSP rules, take water they were entitled to but was unavailable in previous years due to the drought.

Can you provide a more detailed overview of the key issues which resulted in non-compliance?

  • The draft Barwon Darling water resource plan included an estimation based on past practices to embargo Barwon-Darling diversions to support the security of supply for Broken Hill town water. With the completion of the pipeline from the NSW Murray River in February 2019, the embargos are no longer required and the embargo estimating method is redundant. The embargo was not taken out of the modelling which resulted in skewed results – if the embargo had been taken out, we would have been compliant.
  • The main model used in the annual permitted take method was calibrated to match recorded usage volumes returned by pump meters prior to new meters being rolled out in the Barwon Darling. The new meters generally reading differently to the previous meters which resulted in significant inconsistencies between current actual recorded usages and the modelled forecast.
  • The Commonwealth is still to complete 1.6GL of the 32GL target of water recovered for the environment under the Basin Plan in the Barwon Darling. It was assumed in the Basin Plan that full recovery would be achieved by the start of the 2019-20 water year. The shortfall has provided more water to be available for consumptive purposes during 2019-20. This incomplete recovery is beyond NSW’s control.
  • The prevailing climatic conditions in the Barwon Darling prior to and during 2019-20 was also a contributing factor. Following several years of extreme drought, significant rainfall fell across the northern basin in the second half of the 2019-20 water year triggering flows in northern NSW and Qld tributaries and the Barwon Darling. Once sufficient flows to Menindee were secured and s324 restrictions to access lifted, licence holders took advantage of the opportunity to legally extract water for the first time for several years, lifting recorded usage under A, B and C class licences from zero in 2018-19 to 234GL for 2019-20.

Was the non-compliance result expected?

The Barwon Darling non-compliance was an unexpected result, even given the extreme conditions experienced during the 2019-20 water year. The department expected compliance would be achieved.

Why wasn’t the reasonable excuse accepted?

The department hadn’t implemented all of the procedures it said it would in the proposed water resource plan including the NSW extraction limit assessment. However, we are completing this now and will ensure it is completed every year when water is accessed under A, B and C class licences moving forward.

Why is the first year SDL is being measured?

On 1 July 2019 the Basin plan reset the compliance accounting which meant that, unlike the Murray Darling Basin cap, there were no water credits from previous year – 2019-20 was year zero.

Under the Basin Plan, 2019-20 is the first water year that compliance with the SDL is enforceable, meaning action must be taken by Basin states to address non-compliance.

From 2012-13 to 2018-19, compliance with SDL had been calculated each year on a trial basis (non-enforceable) while compliance methodologies and new models and process such as reasonable excuse procedures were being developed.

What is being done to ensure compliance going forward?

The department has submitted a ‘make-good’ plan to the MDBA on how it will rectify the non-compliance and also acknowledges the modelling needs improving and is undertaking a project to recalibrate metres which will improve the accuracy of the data going into the modelling.

The department is committed to Sustainable Diversion Limit compliance and will continue to work with the MDBA on next steps.

What does this mean for Barwon-Darling water users?

The department’s commitments to the MDBA in the make-good plan will not affect Barwon-Darling water user accounts or current practices in accordance with the water sharing plan. Actions in the make-good plan include improving the modelling (e.g. removing the historic embargo behaviour), improving metering calibration to better represent take, and assessing compliance with the long-term annual average extraction limit .

The department will continue to engage with water users and other stakeholders on Basin Plan SDL compliance.