Lachlan River

Lachlan River 
Drought Stage

Stage 1 - Normal management

Stage 1 normal operations on 3 September 2020 eased from recovering since 14 August 2020. Previously stage 3 severe water shortage.

Storage Level
  • Wyangala Dam at 58% (700 GL) of active storage compared to 335 GL (27%) on 1 July 2019.
Allocations
  • Zero for general security in 2019/20 and 2020/21 until 4 September when 28% general security allocation announced.
  • All restrictions on general security carryover lifted on 10 August 2020. Carryover previously restricted to 57% in 2020/21 and half the active amount further restricted in 2020/21.
  • Last general security allocation made in August 2017.
  • Full town and domestic and stock allocations but reduced high security allocations to 87% in 2019/20 and 70% in July 2020. Full high security allocations announced on 10 August 2020.
Actions
  • Annual replenishment flows completed in 2019 to provide domestic and stock water.
  • Water Quality Allowance was released in January/February 2019 to reduce issues with blue-green algae outbreaks in the lower Lachlan.
  • Environmental water was delivered to Booligal Swamp in June, Booberoi Creek from June to August and mid Lachlan wetlands from July 2019.
  • Environmental release from Wyangala Dam commenced in September 2019. This provided water into Booberoi Creek, topped up Brewster weir pool and arrived in the Great Cumbung Swamp in mid November 2019.
  • Replenishment flows to lower Lachlan creeks ceased from 8 December 2019 and flows to the Willandra Creek system ceased from December 2019.
  • Water Quality Allowance was being delivered in the Lower Lachlan during February 2020 to assist with maintaining end of system flows and to improve water quality.
  • Assistance provided to Cowra and Condobolin to access groundwater supplies.
  • Translucent environmental releases made from Lake Brewster in August 2020 to conserve volumes in Wyangala Dam.
  • Stock and domestic replenishments commenced in September 2020.
Issues
  • Inflows into the Lachlan normally occur in winter/spring. Minimal inflows occurred in 2019–close to the record minimums.
  • Since July 2020 over 400 GL of inflows occurred.
Outlook
  • Further inflows will contribute to increased general security allocations.