About the document
This report is the product of the second year of monitoring and evaluation in the Murrumbidgee under the Commonwealth Environmental Water Office’s Long Term Intervention Monitoring (LTIM) Project. The report evaluates the contribution of Commonwealth environmental water to environmental outcomes in 2015-16, complementing the first year of LTIM Project monitoring and evaluation work undertaken in 2014-15 and previous short term monitoring and evaluation work undertaken in 2011-12, 2012-13, 2013-14.
The Murrumbidgee LTIM Project identified a number of key environmental outcomes achieved through the use of environmental water in 2015-16, including:
- Environmental water was delivered to around 16,000 hectares on the Lowbidgee floodplain supporting water quality.
- Native fish numbers in wetlands increased from the previous year. The delivery of water to wetlands coincided with spawning in at least nine native species of fish including the critically endangered silver perch (EPBC Act). In wetlands, carp gudgeon, Australian smelt and bony herring successfully recruited, and Murray cod juveniles were seen in the Nimmie-Caira for the first time since monitoring began in 2008.
- Watering supported wetland and refuge habitats and maintained water quality in the Nimmie-Caira, Redbank and mid-Murrumbidgee wetlands. This stimulated micro-invertebrate populations, which support wetland and riverine food webs, increasing food resources for fish, frogs, turtles, waterbirds and other animals.
- Waterbirds such as threatened Australasian bitterns (EPBC Act), freckled ducks and magpie geese were recorded foraging and nesting, with some breeding in wetlands where environmental water had been contributed.
- Nine aquatic plant communities and 43 water-dependent species were recorded across 12 wetlands. In Yarradda Lagoon important water dependant native species, including spiny mudgrass, tall-spike rush and fringe lily re-established following successive years of environmental watering.
- Breeding activity for six frog species (plains froglet, barking marsh frog, inland banjo frog, Peron’s tree frog, southern bell frog and spotted marsh) was recorded. The vulnerable southern bell frog (EPBC Act) was recorded at Yarradda Lagoon for the first time since the 1970’s.
The report is presented in three parts:
- An executive summary;
- A non-technical synthesis section; and
- A technical appendices section which provide detailed methods, analyses and results for each indicator.
This report is the second of five to be produced for the Murrumbidgee Selected Area under the LTIM Project, with monitoring and evaluation being undertaken from 2014-15 to 2018-19. The data and evaluation report from this project are being combined with those from six other LTIM Project Selected Areas within the Basin, as part of a Basin-scale evaluation of the contribution of Commonwealth environmental water to the environmental objectives of the Basin Plan being led by the Murray-Darling Freshwater Research Centre.
In addition to assisting the Office to demonstrate environmental outcomes, the LTIM Project is designed to allow adaptive management of the water holdings. As such, identified outcomes and limitations are used to inform environmental watering in future years leveraging the best available, contemporary scientific knowledge.