Water for environment outcomes 2023-24

Water for the environment is a share of the water available in our dams and rivers that is managed to support the ongoing health of local waterways along with the native plants, animals and local communities that rely on them.

We help manage water for the environment to deliver benefits for communities and important environmental assets across New South Wales.

New South Wales is home to a unique array of native plants and animals that rely on our rivers and wetlands.

Since river regulation, our rivers and floodplains connect less often than is needed to remain healthy.

We use the best available science, management experience and local knowledge to identify priority watering sites.

This outcomes report details the work we do in 10 catchment areas to support our river systems and meet the needs of native plants, native fish, waterbirds, and other water-dependent wildlife:

• New South Wales Murray and Lower Darling water resource plan area – 619,257.1 megalitres delivered to multiple sites in the Murray and Baaka – Lower Darling catchments
• Murrumbidgee water resource plan area – 478,616.2 megalitres delivered to multiple wetlands in the Murrumbidgee catchment
• Lachlan water resource plan area – 47,073.8 megalitres delivered to wetlands, rivers and creeks in the Lachlan catchment
• Macquarie–Castlereagh water resource plan area – 206,212.5 megalitres delivered to the Macquarie Marshes, Macquarie and Cudgegong rivers
• Gwydir water resource plan area – 27,049.9 megalitres delivered to watercourses and wetlands in the Gwydir catchment
• Barwon–Darling Watercourse water resource plan area – 64,436.4 megalitres protected down the Barwon–Darling watercourse
• Intersecting streams water resource plan area – 8,369.5 megalitres delivered to floodplains in the Intersecting Streams catchment
• Namoi water resource plan area – 12,879.0 megalitres delivered into the Namoi–Peel rivers
• New South Wales Border Rivers water resource plan area – 1,437.0 megalitres delivered to Border Rivers
• Snowy and Snowy montane area – 295,993.0 megalitres delivered into Snowy and Snowy montane catchments.

Executive summary

In 2023–24, the Department of Climate Change, Energy, the Environment and Water’s Biodiversity Conservation and Science group managed the protection and delivery of approximately 1,761,324 megalitres of water across 39 delivery events for the environment. This water for the environment was sourced from NSW, Commonwealth, and joint government water accounts and delivered to key sites across the state.

Teams worked to support restoration of habitat to provide feeding, breeding and movement opportunities for native fish, waterbirds and frogs.

In natural flowing rivers we worked with other water agencies to protect some instream flows to provide benefits for communities and the environment.

We continued our work with NSW community-based environmental water advisory groups to prioritise sites to receive water and build on the successes of previous years. We collaborated with numerous landholders, Aboriginal people and community members across the rivers and floodplains where we work. The support and cooperation of stakeholders is critical to the successful outcomes achieved. Water was used strategically to:

• support water bird health
• support native fish health
• support native vegetation health
• connect and replenish refuge sites, wetlands and rivers.

Monitoring, evaluation and reporting update

The Water for the Environment Monitoring, Evaluating and Reporting Team measures environmental responses to flows, including water for the environment deliveries. It does this by tracking indicators of river and wetland health across 4 environmental themes:

• river flows and connectivity
• native vegetation
• waterbirds
• frogs.

By monitoring the different aspects of these indicators over time, we can measure progress toward meeting NSW long-term water plan and Basin Plan objectives. We can also continually improve how we deliver water for the environment by increasing our understanding of how river and wetland systems respond to flow and flooding regimes.

Our monitoring efforts focus on wetlands that receive water for the environment, including the Gwydir Wetlands, Macquarie Marshes, lower Lachlan wetlands, Lowbidgee floodplain and the Millewa Forest. We also extended our monitoring efforts to the systems outside of the Basin including Narran Lakes and the Snowy River.

We track inundation extent and frequency in floodplain wetland habitats, vegetation community composition and extent, and responses of waterbird and frog communities to flows including water for the environment.

We use a variety of approaches to monitor important indicators of water-dependent ecosystems such as:

• satellite imagery to track inundation and flooding regimes
• depth loggers to understand wetland hydrology
• aerial and ground surveys of waterbird populations
• vegetation mapping using high-resolution imagery
• on-ground surveys of plant species composition
• acoustic recordings and observation to monitor frogs
• drone image capture of waterbird breeding sites, vegetation survey sites and of inundated habitats.

We partner with other agencies, including the Commonwealth Environmental Water Holder (CEWH), to collaborate with their monitoring, evaluating and reporting providers including independent researchers, tertiary institutions, and community groups to improve our understanding through complementary monitoring programs.

We work closely with other programs within the Department of Climate Change, Energy, the Environment and Water, such as Saving our Species and NSW National Parks and Wildlife Service. We also work with other agencies such as the NSW Department of Primary Industry – Fisheries, and the Murray–Darling Basin Authority through The Living Murray Program.

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 environmental water use (Matter 9.3) and a 5-yearly evaluation of ecological outcomes at the asset scale (Matter 8), which is due in late 2024.

We provide regular updates to the community through our website and stakeholder engagement.

The year in review

The year began with most dams full and high water allocations, with water remaining in the landscape from the previous year. These conditions allowed water to be delivered to river and wetland habitats according to annual water plans. As the year progressed over spring and summer, average rainfall shifted to close to or above average. Water for the environment was delivered to enhance river and wetland connectivity to support native vegetation, waterbird and frog species, native fish migration and recruitment.

River flows and connectivity

In 2023–24, water for the environment deliveries and natural river flows inundated areas of floodplain wetland, including critical flood-dependent habitats within non-woody wetlands, lignum shrublands, river red gum forests and woodlands, and coolibah and black box woodlands.

We used satellite imagery to measure the total area of the floodplain landscape that was inundated during the 2023–24 water year in major wetland systems:

• Gwydir Wetlands (including Mallowa Creek and Mehi River): just over 18,000 hectares were inundated, including 42% of non-woody wetland habitat area, 29% of river red gum forest and 26% of flood-dependent shrubland area.
• Macquarie Marshes: 38,540 hectares were inundated, including 40% of non-woody wetland habitat area, 69% of river red gum forest, 36% of river red gum woodland area and almost 20% of flood-dependent woodland area.
• Lower Lachlan: 96,754 hectares were inundated, including 61% of non-woody wetland habitat area, 43% of river red gum forest and woodland area, and 26% of flood-dependent woodland area.
• Lowbidgee floodplain: 52,516 hectares were inundated, including 89% (7,614 hectares) of open water lakes and non-woody wetland vegetation, 49% (33,435 hectares) of river red gum forests and woodlands, and 7% (9,180 hectares) of all flood-dependent shrubland and woodland areas.
• Millewa Forest: 29,982 hectares were inundated, including 99% (1,487 hectares) of non-woody wetland area, 80% (25,785 hectares) of river red gum forest and woodland area, and one third (746 hectares) of flood-dependent area.

The area of available habitat in different vegetation communities supported many different waterbird and flow-dependent frog species.

Waterbird surveys

Waterbird ground surveys in spring and late summer detected many different species across the monitored wetland regions.

In the Northern Basin, water for the environment supported a large variety of waterbirds, including many threatened species. In the Gwydir, 40 species were detected, including the NSW endangered black-necked stork. The Macquarie Marshes supported 51 waterbird species, including the NSW-listed blue-billed duck, brolga and magpie goose and migratory shorebirds including Latham’s snipe, marsh sandpiper and sharp-tailed sandpiper. Although Narran Lakes were largely dry, 15 waterbird species were detected on the wet salt lake in the reserve, including the NSW-listed black-necked stork. In the NSW Border Rivers, 27 waterbird species were recorded, including the migratory Latham’s snipe.

In the Southern Basin, water for the environment supported a diverse range of waterbird species. A total of 45 waterbird species were detected in the lower Lachlan, including the endangered Australasian bittern, and 40 waterbird species were identified in the mid-Lachlan, including the vulnerable sharp-tailed sandpiper. Across the Murrumbidgee 40 species were recorded on the Lowbidgee floodplain including the Australasian bittern and Australian painted snipe, and 24 were recorded in the mid-Murrumbidgee . Along the Murray, 40 different species were detected in the lower Murray and 33 waterbird species were observed in the mid-Murray.

Overall waterbird breeding activity was low due to drier conditions across all wetland regions of the NSW Murray–Darling Basin in 2023–24. Across the Lowbidgee floodplain and along the Murray, there were small cormorant breeding sites with less than 50 nests per site spread across the 2 systems. There were notable exceptions. On Lake Brewster in the Lachlan catchment, the third consecutive large pelican breeding event was observed with almost 23,000 nests active over the nesting period supported by water management. In the NSW Murray, ibis nesting and breeding was recorded on Gol Gol Lake for the first time. Even though the Narran Lakes system was largely dry, a small pelican breeding event was observed on the edge of Narran Lake, which still held some water over early summer 2024. Intensive monitoring of waterbird breeding sites is vital for seasonal adaptive management of environmental water deliveries to support waterbird recruitment.

Frog surveys

During the 2023–24 spring–summer, the delivery of water for the environment along with other water sources, provided wetland habitat for frogs and supported breeding across many monitored sites.

Frog surveys in the Northern Basin were in their ninth year. For the 6 flow-dependent frog species recorded, most had distributions close to or above long-term averages in the Macquarie Marshes and Gwydir Wetlands. In the Macquarie Marshes, the most abundant species were the barking marsh frog, spotted marsh frog and eastern sign-bearing froglets. In the Gwydir Wetlands, the barking marsh frog, spotted marsh frog and salmon-striped frog were the most abundant. Breeding of flow-dependent frog species was diverse and widespread in both wetlands.

In the Southern Basin, frog surveys in the Lachlan were conducted for the second year in spring and summer 2023. The 6 flow-dependent frog species known to inhabit the Lachlan were recorded: the threatened southern bell frog, spotted marsh frog, Peron’s tree frog, inland banjo frog, barking marsh frog and eastern sign-bearing froglet. These species will breed when the wetlands are wet, regardless of rain. Breeding was widespread with breeding activity, such as male calling, egg masses, tadpoles and juveniles, observed at a high proportion of sites (>80%). This helped confirm that the wetlands provided breeding habitat for frogs. The southern bell frog was observed at just over half of the sites and there was evidence of breeding in September and again at a few sites in November to early-December. Under the Saving our Species program, frogs were surveyed using acoustic data collection methods, but this has not yet been processed.

Frog surveys in the Snowy River and upper Murrumbidgee were in their third year and conducted in mid-November and early December 2023. The 9 species observed were: whistling tree frog, common eastern froglet, eastern sign-bearing froglet, eastern banjo frog, stony creek frog, spotted marsh frog, striped marsh frog, smooth toadlet and alpine tree frog, with 7 of the 8 flow-dependent species previously observed in the region. The threatened alpine tree frog sub-species was heard calling at 3 sites in the upper Murrumbidgee and one site on the Snowy River – these sites are all above 1,100 metres altitude. The smooth toadlet, a rain-responsive species, was also observed and heard calling. Frog calling indicates breeding and was widespread and diverse with males calling to attract females. Tadpoles were also observed at many sites, providing further evidence of breeding activity.

Water holdings and trade

The Department of Climate Change, Energy, the Environment and Water (the department) is the lead agency for the delivery of water for the environment in New South Wales. This includes collaboration on the delivery of Commonwealth water held by the Commonwealth Environment Water Holder.

This chart summarises current water holdings, or State ‘held’ water for the environment, recovered to 30 June 2024 (megalitres).

Water trade

The department uses the water market to:

• move water to where it is needed most
• help pay water-use licence fees
• support small infrastructure projects to improve environmental outcomes.

Trades typically commit less than 5% of the water available to the environment and are a small proportion of the total trades made by other market participants. In 2023–24, a net volume of 13,626 megalitres of surface water allocation was sold across catchments. An additional 2,000 megalitres of ‘event based’ supplementary water and 2,797 megalitres of carryover space was sold in the Murrumbidgee.

More information about water trade announcements and reporting is available.

Partners

We work with a range of partner agencies, organisations and individuals to achieve/secure effective and efficient delivery of water to our rivers and wetlands.

These include:

• Department of Primary Industries – Fisheries
• Southern Connected Basin Environmental Water Committee
• Northern Basin Aboriginal Nations
• environmental water advisory groups
• Aboriginal peoples
• Murray Lower Darling Rivers Indigenous Nations
• Murray–Darling Wetlands Working Group
• field naturalists and bird-watching community groups
• landholders
• recreational fishers
• universities
• Murray–Darling Basin Authority
• Commonwealth Environmental Water Holder.

More information about some of our partner agencies is available on our terms and definitions webpage.