Lower Murray wetlands

The lower Murray wetlands are dispersed across the Murray River floodplain between Swan Hill and the South Australian border. The system includes a myriad of interconnected creeks, wetlands and floodplains that are ecologically important and reflect the natural character and attributes of the floodplain. While there are hundreds of wetlands across the lower Murray region, only 54 of them have received water for the environment to date.

Regulation and diversion of the Murray River flow have substantially reduced the frequency and duration of the high river flow that would naturally water the lower Murray wetlands. This change to the water regime has been exacerbated by climate change and has reduced the variety and condition of environmental values associated with billabongs and other floodplain habitats.

Water for the environment can be delivered to some wetlands in the region through direct pumping from the Murray River and/or the use of irrigation supply infrastructure. Most wetlands that receive environmental flows can be managed independently of each other.

System map

Environmental watering objectives in the Lower Murray wetlands

Promote carbon and nutrient cycling to enable wetland processes for food webs

Increase the populations of Murray hardyhead in permanent wetlands where they are known to persist 

 Maintain populations of other native fish in permanent wetlands

Maintain populations of native frogs, including the endangered growling grass frog

Increase the diversity, extent and abundance of wetland plants

 Improve the condition of river red gums, black box and lignum communities

Provide feeding and breeding habitat for a range of waterbird species, including threatened and migratory species  and colonial nesting species (such as egrets)

Traditional Owner cultural values and uses

Watering of the lower Murray wetlands supports cultural values such as traditional food sources and medicines and important species, and it provides opportunities for teaching, learning and storytelling.

The Mallee CMA discussed the proposed 2023-24 watering of the lower Murray wetlands with the First People of the Millewa-Mallee Aboriginal Corporation, Latji Latji Mumthelang, Tati Tati Land and Water, Wadi Wadi Land and Water, Murray Valley Aboriginal Corporation, Gilby, Dadi Dadi Weki Weki, Culpra Millee and Munatunga Elders. Tati Tati Kaiejin was invited to discussions.

Discussions covered a range of options for the delivery of environmental flows in 2023-2024 and what the traditional ecological needs are in the current climate. Feedback was positive, with groups in discussions agreeing to the needs and reasoning behind environmental watering. Drawdown and drying were strongly supported in many cases. Understanding the environmental responses to the recent flooding and identifying and protecting cultural heritage were key topics for discussion.

A common foundation of all groups was the importance of water in wetlands for their cultural spirituality and connection to Country.

Social, recreational and economic values and uses

In planning the potential environmental watering actions in Table 5.2.14, the Mallee CMA considered how environmental flows could support values and uses, including:

water-based recreation (such as canoeing, fishing and kayaking)
riverside recreation and amenity (such as bike riding, birdwatching, bushwalking, camping, geocaching, photography and running)
community events and tourism (such as day trips and sightseeing; education programs for school, TAFE and university students; citizen science projects about birds, frogs and bats; and sporting events)
socioeconomic benefits (such as economic benefits for businesses in the accommodation, beekeeping, food and beverage, ecotourism, hospitality and retail sectors; creating a focal point for socialising; and providing natural, green spaces for the local community).

Scope of environmental watering

The term ‘environmental watering’ refers to the active delivery of held environmental water to support particular environmental objectives by altering the flow in a river or the water level in a wetland. While other terms are sometimes used to describe the delivery of environmental water, ‘environmental watering’ is deliberately used here and in seasonal watering statements to ensure consistency in the legal instruments that authorise the use of water for the environment in Victoria.

Table 5.2.14 describes the potential environmental watering actions in 2023-24, their expected watering effect (that is, the intended physical or biological effects of the watering action) and the longer-term environmental objectives they support. Each environmental objective relies on one or more potential environmental watering actions and their associated physical or biological effects.

Table 5.2.14 Potential environmental watering actions, expected watering effects and associated environmental objectives for the lower Murray wetlands

Potential environmental watering action	Expected watering effects	Environmental objectives
Brickworks Billabong (fill in spring/summer, top-ups as required over summer/autumn)	Maintain water levels (the target water level is between 30.8 m AHD and 31.6 m AHD) to inundate ruppia beds, provide nursery habitat for Murray hardyhead and provide high levels of aquatic productivity Maintain water quality suitable for Murray hardyhead Provide shallow-water habitat and exposed mudflats to support foraging and resting waterbirds, including migratory waterbirds
Catfish Billabong (fill in winter/spring)	Fill to 33.5 m AHD to inundate fringing woodland vegetation to improve condition and recruitment Allow water level to draw down over summer and autumn to: promote the growth of a range of aquatic macrophytes that favour different water depth and inundation patterns provide suitable foraging conditions for wading shorebirds Maintain water levels above 30.8 m AHD to maintain permanent habitat for large-bodied and small-bodied native fish
Koorlong Lake (top-up in spring, then as required)	Increase and maintain the water level (the target water level is between 36.7 m AHD and 38.0 m AHD) to support the growth of saline aquatic vegetation, including ruppia, to provide nursery habitat for Murray hardyhead and provide high levels of aquatic productivity Maintain water levels within a 1.3 m range to provide feeding resources for shorebirds and to maintain the Murray hardyhead population
Lake Hawthorn (top-ups in spring, then as required over summer/ autumn)	Maintain water level between 33 m AHD and 33.3 m AHD to encourage the germination and growth of saline aquatic vegetation, including ruppia, and provide mudflat and shallow-water feeding habitat for shorebirds
Robertson Wetland (fill in spring)	Wet fringing river red gum, black box, lignum and vegetation communities (the target water level is 28.4-28.8 m AHD) to improve their condition Inundate cane grass beds to improve their condition and resilience Provide a range of open-water, shallow-water and inundated lignum habitat to provide waterbird feeding opportunities
Wakool Creek (fill in spring)	Inundate and wet outer fringing lignum and vegetation communities (the target water level is 55.4 m AHD) to improve their condition Inundate habitat to provide feeding and breeding opportunities for frogs and waterbirds

Page last updated: 01/07/22