The Water for the Environment Monitoring, Evaluating and Reporting (MER) Program monitors indicators of river and wetland health using 4 major themes:
- river flows and connectivity
- native vegetation
- native animals, including waterbirds and frogs
- native fish.
By monitoring these indicators, we can measure progress towards meeting Basin Plan and long-term water plan objectives. We are also able to continually improve how we deliver water for the environment to meet those objectives.
We monitor environmental flow events and long-term changes in vegetation condition and extent, as well as changes in waterbird and frog populations in response to water management. Our monitoring efforts focus on wetlands targeted by water for the environment, including the Gwydir Wetlands, Macquarie Marshes, Lower Lachlan Wetlands, Lowbidgee Floodplain and Millewa Forest. We have also extended our monitoring efforts to the Snowy River, in partnership with the Department of Planning, Industry and Environment – Water.
We use a variety of technologies to determine whether the environmental water requirements of our river and wetland ecological communities are being met. This includes:
- satellite imagery to track floodplain wetland inundation and changes in vegetation extents
- aerial and ground surveillance to understand vegetation and waterbird responses to the water for the environment deliveries
- acoustic recordings and observation to monitor frogs.
We work with the Commonwealth Environmental Water Holder (CEWH) to deliver water for the environment and ensure improvements to the health of rivers and wetlands in the most effective way. This efficiency extends to monitoring. We collaborate with the CEWH, independent researchers, tertiary institutions, and community groups to improve our understanding and prevent duplication of effort.
We report our findings to the Murray–Darling Basin Authority to meet Schedule 12 requirements of the Basin Plan. Schedule 12 includes annual reporting of ecological outcomes at an asset-scale (Matter 9.3) and a 5-yearly evaluation (Matter 8). The 5-year evaluation is due in 2025. We also provide regular updates to the community through our website and stakeholder engagement.
An independent evaluation of our Water for the Environment MER Program between 2014 and 2019 has also been completed and these findings will be made publicly available later in 2021.
The year in review
Following a dry start to the 2020–21 water year, widespread rainfall across the NSW Murray–Darling Basin resulted in wetter conditions as the year progressed. Increased storage levels enabled water for the environment to be delivered to river and wetland habitats across the state. Targeted habitats included non-woody wetland vegetation, river red gum forests and woodlands, black box and coolabah woodlands and lignum shrublands.
The aim of these deliveries was to support long-term water plan objectives. For example, improved connectivity and inundation across rivers and wetlands included watering:
- 37,705 hectares of Lowbidgee wetlands
- 8919 hectares of Barmah-Millewa forests
- 40,194 hectares of wetlands in the mid and lower Lachlan
- 30,191 hectares of the Macquarie Marshes
- 236,718 hectares of the Gwydir floodplain, including Ramsar-listed wetlands.
The increased areas of wetland habitat and watercourse connectivity improved riparian and floodplain vegetation condition, and supported waterbird and frog breeding.
Waterbird surveys
At the start of the water year, waterbird surveyors in the Gwydir Wetlands, Macquarie Marshes, Mid and Lower Lachlan, Murrumbidgee and Murray wetlands encountered numerous dry sites, with waterbird habitats confined to watercourses and isolated waterholes.
Over the spring and summer, following widespread rainfall and the delivery of water for the environment to wetlands across the NSW Basin, wetlands filled and waterbird habitats increased.
Over this wetter period, we found 51 waterbird species in the Gwydir Wetland System. This included 5 NSW-listed threatened species (freckled duck, black-necked stork, brolga, back-tailed godwit and magpie goose) and 4 migratory shorebird species (Latham’s snipe, sharp-tailed sandpiper, black-tailed godwit and wood sandpiper). There was also an incidental sighting of a nationally endangered Australasian bittern on the Gwydir State Conservation Area in early March 2021. Breeding was detected in 18 waterbird species (including 6 colonially-nesting species) during the 2020–21 surveys.
We observed a high number of waterbirds in the Macquarie Marshes. The 48 waterbird species detected included 3 threatened waterbird species (Australasian bittern, brolga, magpie goose), and large numbers of grey teal, Pacific black duck, hardhead and Eurasian coot. At least 3 colony sites were found in the northern marsh, with 8 additional waterbird species nesting in small numbers, including the Australasian darter, Australian white ibis, little pied cormorant, little black cormorant, eastern great egret, cattle egret, intermediate egret and magpie goose. Other notable waterbird species observed were the migratory Latham’s snipe and wood sandpiper, and the blue-billed duck which is listed as vulnerable in NSW.
In the Mid and Lower Lachlan, we observed 55 species of waterbirds including blue-billed ducks and magpie geese, as well as migratory shorebird species (sharp-tailed sandpiper, Latham’s snipe and red-necked stint) recognised under international migratory bird agreements. The nationally endangered Australasian bittern was heard calling, which was significant as there have been few records of Australasian bitterns in the Great Cumbung in recent decades – the last confirmed record was in 1991. Inundated wetlands also provided habitat for breeding, with 6 active waterbird colony sites identified.
Twenty active waterbird colonies were found in the Murrumbidgee. This included a large ibis colony in the Gayini Wetlands, and smaller ibis, egret, spoonbill, heron and cormorant breeding sites across the rest of the Murrumbidgee catchment. The nationally endangered Australasian bittern, NSW-listed vulnerable blue-billed duck and freckled duck were also found at several Lowbidgee floodplain sites.
Surveys in the Barmah–Millewa Forest under The Living Murray Program identified 48 waterbird species which was a significant increase from the 36 species recorded in 2019–20. Australasian bitterns were recorded calling at Moira Lake and successful breeding of spoonbills, cormorants and ibis was observed.
Frog surveys
Over the 2020–21 summer, natural inflows and the delivery of water for the environment supported frog breeding across many monitored sites.
Nine flow-responsive frog species were identified in the Gwydir over spring and summer. Detected species included spotted marsh frogs, eastern sign-bearing froglets, barking marsh frogs, Peron’s tree frogs, broad-palmed frogs and salmon-striped frogs. Although frog breeding activity was relatively low in spring 2020 due to dry conditions, activity increased for all species over summer following wetland inundation by natural flows and the provision of water for the environment.
Surveys in the Macquarie Marshes also found high levels of frog breeding success. Eight frog species were detected, including all 6 flow-dependent species (spotted marsh frog, barking marsh frog, Eastern sign-bearing froglet, Peron’s tree frog, broad-palmed frog and salmon-striped frog) and 2 arboreal frog species (green tree frog and desert tree frog).
The presence of the nationally vulnerable southern bell frog in the Lower Lachlan was confirmed at 2 locations in the Lachlan’s Great Cumbung Swamp. These latest records of nationally listed threatened species are significant for the Lower Lachlan which was once a stronghold for these species. Southern bell frogs were last confirmed in the Lower Lachlan in 2012.
Monitoring in the Murrumbidgee, as part of a long-term Commonwealth program, found frogs actively calling at most sites that received water for the environment. Southern bell frogs were heard calling at multiple wetlands in Yanga National Park and the Gayini Wetlands, with large choruses also heard at Sunshower Lagoon in the mid-Murrumbidgee.
The Saving our Species southern bell frog conservation project monitored the outcomes for water for the environment in the mid- and lower- Murray regions. Southern bell frogs were found at 15 of 19 monitored sites in the Mid-Murray and 2 monitoring sites in the lower-Murray region.
