WaterNSW corrects record on successful Barwon-Darling connectivity event

WaterNSW corrects record on successful Barwon-Darling connectivity event

29 January 2021

WaterNSW has moved to correct the record – and acknowledge the role our customers played – in the successful resumption of flow connectivity event in the Barwon-Darling.

The Friday (29 January) edition of News Corps’ The Australian newspaper asserted that “The first attempt to send water reserved for the environment down the Darling River is in disarray after irrigators were given the green light to pump despite regular flows falling short of the usual extraction threshold.”

In fact, under a new NSW Government water sharing plan rule, enacted for the first time on January 12, all water in the Barwon Darling upstream of Menindee effectively became temporarily classified as protected water intended to enhance environmental flow.

The new resumption of flow rule objective was to deliver a flow from the Queensland border to the Menindee lakes by suspending irrigation access to what otherwise would have been predominantly irrigation water.

Once authorities were confident the flow would connect the full river, limited access was granted to some irrigators (A class) upstream on Bourke on 24 January. B and C class remained suspended.

With modelling confirming the water will reach Menindee access to all irrigators upstream of Bourke has been restored from 9am, Friday, 29 January.

WaterNSW executive manager system operations, Adrian Langdon said the co-operation of irrigators should not be overlooked in difficult circumstances.

“Irrigators in the unregulated section of the Barwon-Darling have been compelled under the new rule to forego precious water that they would have previously been entitled to utilise,” he said.

“It must be acknowledged that these irrigators have also been subject to the extremely dry conditions and resulting acute water scarcity that have prevailed until recently in the Barwon-Darling, and who have complied with the new rule with good grace.”

Background:

The amount of pumping against A class licences is a very small proportion of pumping in the Barwon-Darling as the vast majority of take is against B and C class licences.

Commonwealth held environmental water (which made up only 5% of the total flow) was ordered by the Commonwealth Environmental Water Office (CEWO) in December before the late December/early January rainfall.

The CEWO requested WaterNSW release water from Copeton and Pindari dams to send environmental flows down the Border and Gwyrdir Rivers (not the Darling) to enrich flows to Collarenebri and potentially through to Walgett.

Natural flows, which historically would have been accessed by irrigators, were protected. Of all the water flowing down the Barwon-Darling, 90-95% was natural tributary flows with the rest consisting of environmental water released from Copeton and Pindari dams in December.

WaterNSW was in constant communication with the CEWO regarding the flows.

The threshold flow targets are clearly documented and the flows in the system are available on WaterNSW website.

This response from the CEWO which was provided to The Australian: - ‘Based on data provided by WaterNSW, between 90 and 95% of the flows at each gauge to Bourke have been from unregulated tributary flows. It would be disproportionate to state that the water for the environment caused the relaxation of the rule to allow pumping. The water for the environment started to be released from dams before much of the recent rainfall.'  

  • Read the full CEWO statement to The Australian:

“The changes to the rules governing water sharing in the Barwon-Darling in late 2020 are a great step forward by NSW in implementation of its Water Reform Action Plan.

“We are seeing water about to reach Wilcannia and destined for Menindee that would not have reached this far under the previous rules.

“Summer rain helped this small environmental flow to extend well beyond its original target range. The flow currently extends from just downstream of Bourke to just upstream of Collarenebri, about 600 river kms.

“Positive results from this flow are being observed along the river including topped-up waterholes, improved water quality, and connectivity allowing fish to access more habitat.

“As at 27 January 2021 a total of 26,657 megalitres (ML) of water had passed Bourke. Only 5.8% - or 1,539 ML - of this amount is water for the environment.  This means that around 95% of the flows at Bourke have been from unregulated tributary flows.

“An unexpected outcome of this combination of larger natural flow and small environmental flow has been the relaxation of the resumption of flow rule. This was announced by NSW on 24 January 2021. There has been ongoing communication between the CEWO and NSW during policy development and implementation of the new rules.

“The current pumping is very limited against the smallest licence class in the Barwon-Darling. It would be disproportionate to state that the water for the environment caused the relaxation of the rule to allow pumping.

“Water for the environment from the Northern Waterhole Top-up flow is protected from extraction under the new rules and a small proportion of this water is expected to flow all of the way to Menindee.”

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