Barwon-Darling River

Barwon-Darling River 
Drought Stage

Stage 1 - Normal management

Stage 1 normal operations – eased from Stage 2 recovering in April 2021- de-escalated from Stage 4 critical to Stage 3 severe on 23 March 2020 and then to Stage 2 on 1 May 2020.

Allocations
  • Allocations announced on 1 July 2020, and normal flow class access has been available for most of 2020/21. However, from 12 to 27 January 2021 A,B, C class access was prohibited as new resumption of flow rule under the amended water sharing plan was triggered.
  • Allocations announced on 1 July 2019, but water unable to be pumped by irrigators until temporary water restrictions were lifted in late February 2020 above Culgoa junction and 6 March below Culgoa junction.
  • From end of February 2020 until June 2020, river levels variously triggered A, B and in some sections C class pumping along the Barwon-Darling.
  • Good flows in April 2021 are providing B or C class access along the river
River Level
  • A release of environmental water Northern Connectivity Event in autumn/winter of 2018 from the Gwydir and Border Rivers provided a small flow down to Menindee Lakes.
  • During March to August 2019 inflows from tributaries, local rainfall and another environmental release - Northern Fish Flow event - restarted flows in some sections and replenished town weir pools and fish refuge pools. However, flows only reached to just upstream of Bourke because of the dry conditions.
  • Rainfall in early November 2019 provided flows down the Warrego River and flows over the Bourke town water weir. This was the first time in over 400 days that flows had occurred over the Bourke town weir.
  • Flows re-commenced along the Barwon-Darling River from February 2020 as a result of inflows from the northern catchments which were restricted from extraction through river pumping and from floodplain harvesting across the Northern Basin. By March 2020 flows had reached Wilcannia and began entering Menindee Lakes from 10 March 2020.
  • System dried again for the second half of 2020, until further natural inflows from the northern tributaries in January 2021 contributed to flow in the upper part of the river. This was enhanced by a further small environmental release from the Gwydir and Border Rivers – Northern Waterhole Top-Up release.
  • Rainfall across the north-west and Queensland in March 2021 is contributing inflows to the Barwon-Darling River and flows have begun reach Menindee Lakes from April 2021.
Actions
  • Despite natural flows in the upper river in January 2021 and the environmental release - Northern Waterhole Top up flow (total 8 GL released from Gwydir and Border rivers), the river at Tilpa and Wilcannia was not flowing. On 12 January 2021 this triggered the new resumption of flow rule in the Barwon-Darling water sharing plan as Wilcannia has been below 200 ML/day for 90 days. No irrigation access upstream is permitted until there is a forecast flow at Wilcannia of 400 ML/day for a minimum of 10 days, or a forecast flow to pass Bourke of 30,000 ML.
  • Restrictions placed on pumping from mid-January to end of February 2020 to protect inflows from northern catchments for critical needs. These were lifted upstream of Culgoa junction on 27 February and downstream of Culgoa junction on 6 March 2020.
  • Restriction on A, B, C class pumping between Culgoa junction and Menindee Lakes between 4 November to 31 December 2019 to protect inflows for critical needs.
  • A restriction on pumping from the lower Namoi River applied on 31 March 2019 allowed some flow to reach Walgett, at the junction with the Barwon River. This restriction was repealed on 6 May 2019.
  • The 2019 environmental water release (Northern Fish Flow)  of 7.4 GL from Glenlyon Dam in the Border Rivers and 26 GL from Copeton Dam in the Gwydir reached Warraweena on 28 July, but not Bourke - travelling over 1,500 river kilometres. Restrictions were imposed on A, B and C class pumpers in the Barwon-Darling to protect the flow.
  • From March to April 2018 access was restricted to protect natural inflows for critical needs.
  • This was followed by the 2018 environmental release (Northern Connectivity Event) from Copeton of 18.9 GL and Glenlyon Dam of 4.3 GL which provided a small flow along the full length of the Barwon-Darling down to Menindee Lakes. Restrictions on access also applied to protect the environmental release.
  • Two aerators installed in the Collarenebri weir pool in collaboration with local fishing club and Aboriginal community.
  • Funding provided to towns for emergency bore supplies and in the case of Walgett and Bourke for works to improve quality.
  • Critical fish refuges pools have been mapped along the Barwon-Darling.
Issues
  • Until restrictions were lifted towards the end of February/start of March 2020, Barwon-Darling irrigators had not been able to pump any significant water since mid-2017. Restrictions re-imposed on 12 January 2021 prohibiting irrigation access for just two weeks under the new resumption of flow rule in the water sharing plan. As per the rules, restrictions were lifted once a flow to pass Bourke of 30,000 ML was forecast.
  • Prior to the 2020 flows, flows had been mostly protected to replenish town, domestic and stock supplies and refuge pools.
  • In 2019 towns had to access artesian bore water because of lack of surface water supplies. Concerns over higher sodium levels.
  • A number of fish deaths because of drying refuge pools in 2019.
  • Return of flows along the Barwon-Darling River in 2020 resulted in fish spawning and dispersal of larvae down river to the Menindee Lakes.
  • High flows are continuing along the river.  Although dissolved oxygen levels at the front of the flows are very low, no fish deaths have been reported.
Outlook
  • As at 15 April 2021, good flows are occurring along the Barwon-Darling as a result of rainfall in March across the northern NSW valleys and Queensland. These are expected to continue for some weeks.