Environmental watering in the Lower Murray-Darling catchment in 2021-22
These Commonwealth environmental watering actions follow from the Water Management Plan 2021-22, having regard to Basin annual environmental watering priorities and, the Basin-wide environmental watering strategy.
This page will be updated as water use decisions are made by the Commonwealth Environmental Water Holder.
A summary of previous years' Commonwealth environmental water use in the Lower Murray-Darling river system is available at history.
For further information about Commonwealth environmental watering in the Lower Murray-Darling river system and the outcomes achieved, please refer to our Monitoring Reports.
| Watering action | Status of Commonwealth action |
|---|---|
| River Murray flows | In progress |
| Lower Murray and end of system flows | In progress |
| Lower Darling/Baaka flows | In progress |
| Great Darling Anabranch | In progress |
| Hattah Lakes | Complete |
| NSW Lower Murray wetlands | In progress |
| Weir Pool Manipulation and SA Floodplains | In progress |
| South Australian Wetlands | In progress |
River Murray flows
Status: In progress
About the watering
Commonwealth environmental water is being delivered to provide benefits along the length of the River Murray in 2021-22, contributing to flows and targeting outcomes from Hume Dam through to the Coorong. The event builds on the outcomes and learnings from The Southern Spring Flow 2019 and The Southern Spring Flow 2020.
Commonwealth environmental water deliveries will be pooled with water available to other environmental water holders for use in winter and spring. About 400,000 ML of water for the environment (including Commonwealth and state-held water) is available for the watering action, with the majority flowing the full length of the Murray through to the Lower Lakes and Coorong. The key objectives are to:
- Support native fish and provide the conditions they depend on every year to feed and breed.
- Connect the River Murray with its anabranches and creeks, to support aquatic plants, enable fish movement and provide food resources for aquatic animals.
- Maintain core wetlands that are important for waterbirds.
For more information visit: Murray Wetland Flow 2021.
Lower Murray and end of system flows
Status: In progress
About the watering
The Commonwealth’s held South Australian allocation of 162 GL contributes to baseflows in the Lower Murray and is delivered as part of the South Australia entitlement across all months of the year. A portion of this water is used in South Australian Wetlands (see details below).
This water delivery may be complemented by up to 220 GL of water delivered directly to South Australia to protect critical functions and ecosystems during spring to autumn and support connecting flows to the end of the system. Additional Commonwealth environmental water will also reach the Lower Murray as moving downstream from watering actions in tributaries in upstream states such as the Upper Murray (see above), Goulburn, Lower Darling/Baaka and Murrumbidgee rivers.
Commonwealth environmental water is targeting the following outcomes in the Lower River Murray channel:
- Support processes such as primary and secondary production, mobilisation and transport of nutrients, carbon cycling and biotic dispersal throughout the River Murray catchment, which underpin food webs and are essential to the health of the system.
- Provide native fish with in-stream habitat and connect the river channel with wetlands and anabranches to maintain native fish condition and provide opportunities (where feasible) for recruitment, spawning and movement.
- Maintain water quality and reducing risks of stratification and algal blooms by increasing the extent and duration of flowing water in the river channel.
Water delivered to the Lower Lakes and Coorong is targeting the following outcomes:
- Support flows through the barrage fishways to provide a connection between the River Murray channel, Lower Lakes and Coorong and allow the seasonal movement of migratory fish species.
- Reduce salinity levels in the north lagoon of the Coorong to support estuarine fish.
- Support native vegetation fringing the Lower Lakes, which in turn provides habitat for small-bodied native fish and frogs.
- Provide habitat and food to support waterbirds.
- Provide water quality benefits for the river and Lower Lakes through salt export from the River Murray.
- Contribute to the maintenance of critical habitat, water quality, water level, and the provision where possible of localised refuge sites as required, in both the Lower Lakes and Coorong.
River Murray at Waikerie and pelicans on the Coorong. Photos: CEWO
Lower Darling/Baaka flows
Status: In progress
Following periods of cease-to-flow conditions, associated fish deaths in 2018-19, and the reconnection of the Darling/Baaka to its connecting rivers, tributaries and wetlands in early 2020, there are signs that native fish populations (like Murray cod and golden and silver perch) are beginning to recover.
Further inflows to the Menindee Lakes from the northern Basin in autumn and winter 2021 (including water protected by “First Flush” protection rules) have significantly boosted water levels in the Menindee Lakes.
During 2021-22, delivery of water for the environment (in conjunction with operational releases) is aiming to build on the positive native fish outcomes seen in 2020-21 by providing elevated baseflows in the lower Darling/Baaka during the Murray cod nesting period, and potentially providing a ‘pulse’ of flow later in spring for golden perch breeding.
Environmental releases into the lower Darling/Baaka are also expected to support the dispersal of juvenile golden perch that spawned upstream of the Menindee Lakes into the lower Darling/Baaka and ultimately the River Murray.
Environmental watering in 2021-22 will be informed by previous monitoring results as well as additional monitoring expected to be undertaken during 2021-22.
For more information and updates during the event see: 2021 Lower Darling-Baaka and Great Darling Anabranch spring fish flow.
The 2020-21 monitoring results are available at: Monitoring native fish response to environmental water delivery in the lower Darling River 2020-2021.
Fish surveys found young golden perch have travelled from the northern tributaries and are using the Menindee Lakes as nursery habitat. Photo: DPI Fisheries
Great Darling Anabranch
Status: This action is in progress
About the watering
Recent inflows to the Menindee Lakes (described above) have included significant flows into Lake Cawndilla. This has provided an opportunity to give a much-needed drink to the Great Darling Anabranch, which has been dry since 2016-17.
The Great Darling Anabranch flow commenced in September 2021 via an ‘operational spill’, followed by water for the environment, which is creating a ‘Golden Highway’ for juvenile golden perch and other native fish in Lake Cawndilla to move down the Anabranch and disperse throughout the Murray valley.
In addition to supporting fish movement, the flow is also expected to provide benefits for plants along the Anabranch and create additional feeding grounds for ducks and other waterbirds.
For more information and updates during the event see: 2021 Lower Darling-Baaka and Great Darling Anabranch spring fish flow
Hattah Lakes
Status: This action is complete
About the watering
Water for the environment was being delivered to Hattah Lakes in spring 2021. Following the 2016 natural flooding event, the majority of the Ramsar-listed Hattah-Kulkyne Lakes complex had a drying phase.
Delivery of water for the environment in April-May 2021 inundated 13 of the 18 lakes in the complex, to allow wetland plants and animals time to establish prior to the larger planned delivery in spring 2021. The spring water delivery took advantage of high natural flows in the River Murray to build on the autumn flows to fill most of the lakes to promote river red gum and aquatic vegetation growth and condition, support waterbird and small-bodied native fish breeding and provide nutrients and other floodplain material back into the River Murray channel to boost food-webs in the river.
Commonwealth environmental water was not required for this watering action, as unregulated entitlements held by The Living Murray and Victorian Environmental Water Holder were able to be used opportunistically in conjunction with the high River Murray flows, preserving regulated Commonwealth water allocations for use in other watering actions described on this page.
NSW Lower Murray Wetlands
Status: In progress
About the watering
Commonwealth water for the environment is being delivered by the Murray-Darling Wetlands Working Group (MDWWG) in combination with the MDWWG’s Environmental Water Trust allocations to several priority wetlands on or adjacent to Wingillie Station during 2021-22.
Several wetlands on the property, which is now managed for environmental purposes by the Hazel L Henry Farmland Nature Refuges, are being watered this year to complement natural high flows from the River Murray that filled some of the other wetlands on the property.
The watering actions aim to improve condition of floodplain and wetland vegetation, and provide habitat for waterbirds and frogs, including the threatened southern bell frog.
A particular focus of the watering is to maintain suitable conditions for the endangered Murray hardyhead in Little Frenchman’s Creek. For the last three years, water for the environment has been delivered to support the translocation of Murray hardyhead from the Riverland, SA, to Little Frenchman’s Creek. The project aims to reduce the risk of the species becoming extinct and the site is the only location where the species is known to live in New South Wales. Ongoing Murray hardyhead surveys at the site are being carried out to monitor the Murray hardyhead population and to inform delivery of water to target suitable salinity levels for the fish within the wetland. For more information about this project, see:
- the media release: Little Aussie battler Surviving against the odds
- Short-term intervention monitoring associated with the translocation of Murray Hardyhead into Little Frenchmans Creek, Wingillie Station NSW
The watering and monitoring at Wingillie Station is part of a joint project involving the Australian Government, the Murray Darling Wetlands Working Group, the Hazel L Henry Farmland Nature Refuges, and NSW Department of Planning, Industry and Environment. The NSW Department of Primary Industries (Fisheries) and Aquasave - Nature Glenelg Trust are additional key partners for the ongoing monitoring and management of the Murray hardyhead population in Little Frenchman’s Creek.
Weir Pool Manipulation and SA floodplains
Status: In progress
About the watering
Commonwealth environmental water has been assigned to support weir pool manipulation at Locks 2, 4, 5, 7, 8, 9 and 15. The lowering and raising of weir pools aims to provide increased variation in river flows, which underpin important ecological functions, with benefits for both in-stream habitats (by increasing river flow when weir pools are drawn down) and low-lying floodplain areas (by inundating wetlands that sit slightly above normal weir pool levels, and recreating a more natural wetting and drying pattern for pools that are normally connected to weir pools).
In conjunction with the raising of lock 4 and 5 weir pools, Commonwealth environmental water is supporting the watering at Pike and Katarapko floodplains in South Australia using recently constructed watering infrastructure. The infrastructure is designed to provide a more natural wetting and drying cycle within the floodplain, creeks and wetlands, which due to river regulation no longer get the water they need. Outcomes expected from this event include improving health and condition of important tree communities such river red gums, black box and lignum and supporting populations of frogs, water birds and yabbies. Watering at these floodplain sites will build on the outcomes from watering in 2020-21, and this will be the second time these works have been used to facilitate watering of these sites.
Photos showing benefits of raising Lock 5 weir pool in South Australia. Photos: DEW
South Australian Wetlands
Status: In progress
About the watering
As part of ongoing partnerships, Commonwealth environmental water will be made available to:
- Banrock Station (up to 6,167 ML over five years to 2023-24, as part of a continued commitment between the CEWH and Banrock Station)
- Calperum Station (up to 1,904 ML in 2021-22 as part of a five-year partnership to 2024-25)
- Renmark Irrigation Trust (up to 3,700 ML over five years to 2023-24, as part of a continued commitment between the CEWH and Renmark Irrigation Trust)
- Murraylands and Riverland Landscape Board (up to 12,956 ML in 2021-22) as part of a five-year partnership to 2024-25
- Nature Foundation Limited (up to 2,490 ML in 2021-22)
This water is being delivered to a number of creeks and wetlands along the Lower Murray floodplain and adjoining the Lower Lakes in 2021-22.
The purpose of the watering events is to contribute to environmental outcomes such as maintaining the condition of floodplain trees, understorey vegetation and submerged aquatic plant communities and providing refuge for waterbird, fish and frog species. A number of threatened species such as the Murray hardyhead fish, Regent parrot and southern bell frog are expected to benefit from flows targeted to known habitat sites, along with international migratory bird species.
Watering events will be implemented across South Australia with the assistance of traditional owners, private landholders, Landcare and community groups, local councils, the Murraylands and Riverland Landscape Board and the South Australian Department for the Environment and Water.