Priorities for 2017–18
Climate models are indicating a neutral El Nino-Southern Oscillation for the second half of 2017 with warmer and drier than average conditions expected across Australia. As a result of recent floods and high inflows, availability of planned and licensed water from storage is expected to be relatively high.
The Resource Availability Scenario for 2017–18 forecasts moderate to dry conditions. Therefore, the emphasis will be on ensuring environmental assets maintain ecological health.
Water managers plan to build on the successes of the previous watering year through the careful management of environmental flows in 2017–18.
Further details on watering priorities for 2017–18 can be found in the Statement of annual environmental watering priorities 2017–18 (PDF 2.5MB).
Highlights from 2016-17
Positive reponse from fauna and flora
In 2016-17, the River Murray system experienced very wet conditions, with higher than average inflows generally only seen in 11 out of 100 years (DPIW 2017).
Environmental water manager for the Murray and Lower Darling Paul Childs noted a generally positive response from fauna and flora at sites that received environmental water in 2016-17.
A Murray cod spawning event triggered by floods in the lower Darling was the most significant such event observed in more than 20 years. Environmental water was used to allow the Murray cod to complete their breeding cycle and boosted the food web in order to sustain the growing population. A managed flow down the Darling Anabranch assisted the dispersal of tens of thousands of juvenile golden perch from Lake Cawndilla into the River Murray system.
High river flows from July to October 2017 resulted in the establishment of a colonial waterbird rookery within the Gulpa Creek wetland complex. The rookery consisted of hundreds of pairs of Australian white ibis, straw-necked ibis and Royal spoonbills. Also within Coppinger’s Swamp, 15 pairs of little pied cormorants, 93 pairs of little black cormorants and 6 pairs of Australasian darters were recorded nesting. This event also provided habitat for the Australasian bittern and the Australian little bittern. Juvenile white-bellied sea-eagles were also observed within the wetland complex.
Environmental water was used to successfully maintain nesting and foraging habitat for waterbirds in the Gulpa Creek wetland complex between December 2016 and January 2017. There was also a positive response from vegetation including recruitment of threatened swamp wallaby grass and Moira grass.
The Gol Gol wetlands in the lower Murray attracted tens of thousands of waterbirds including at least 27 species. Glossy ibis and two threatened species - the blue billed duck and freckled duck – were observed at the site.
During spring watering events, the endangered southern bell frog was detected at several private central-Murray wetlands and multiple locations along the Jimaringle-Cockran-Gwynnes creek system. The natural high flows from November 2016 inundated all southern bell frog sites in the lower Murray and Lower Darling catchment, so environmental water was not required in 2016-17. The condition of habitat within these sites is good and will be supported by future watering events.
The Edward-Wakool system had its biggest flood since 1992 resulting in large amounts of carbon and nutrients entering rivers and creeks from the floodplain. As a result, an hypoxic blackwater (low oxygen) event occurred. Oxygenated environmental water was released into the Edward River, Wakool River, Thule Creek, Niemur River and Colligen Creek to successfully create small areas of refuge habitat for native fish. The event was a collaboration between Commonwealth Environmental Water Office, Office of Environment and Heritage, WaterNSW, the State Emergency Service, Murray Irrigation, Wakool Shire Council, Murray River Shire Council and the community.