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The lower Murray wetlands span more than 700 kilometres of linear floodplain along the River Murray between Swan Hill and the South Australian border. This includes creeks, wetlands and floodplains that are ecologically important and reflect the natural character and attributes of the River Murray floodplain.

The regulation and diversion of River Murray flows has dramatically altered the hydrology of the lower Murray wetlands. River regulation has substantially reduced the frequency and duration of the high river flows that are needed to water billabongs and floodplains. This change to the water regime has caused a decline in the environmental values of floodplain wetland sites.

Environmental water can be delivered to some wetlands in the region through a combination of direct pumping from the River Murray and through use of irrigation supply infrastructure. All the wetlands can be managed independently of each other.

System map

Murray System

Environmental watering objectives in the Lower Murray wetlands

bat icon
Improve the condition of river red gums, black box and lignum to provide habitat for large animals (such as lace monitors and bats)
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Provide feeding and breeding habitat for a range of waterbird species including threatened and migratory species and colonial species (such as the egret)
Fish icon
Improve water quality and increase habitat for fish
Plant icon
Increase the diversity, extent and abundance of wetland plant life

Environmental values

The lower Murray wetlands are comprised of multiple wetlands, creek and billabongs on the floodplain of the River Murray. Depending on their location in the landscape, interactions with groundwater and their management history, the wetlands may be permanent, temporary, freshwater or saline. The differences in water regime and water quality among the wetlands provide a range of habitats for plants and animals. For example, permanent, saline wetlands (such as Brickworks Billabong) provide vital habitat for the endangered Murray hardyhead fish. Unlike permanent wetlands, temporary freshwater wetlands fill and dry intermittently. During the filling phase they provide short-term boom periods when river red gum trees and wetland plants grow, spread and provide habitat for aquatic animals.

Social and economic values

There are several irrigation districts in the Sunraysia region that are supplied by the River Murray and contribute significant wealth to the local economy. Camping, fishing and other water-based recreational activities are popular along the River Murray including at some wetlands in the lower Murray system. Waterbirds provide opportunities for bird watching and hunting. Aboriginal culture is strongly linked to the floodplain of the River Murray, which for many thousands of years would have maintained a concentrated population due to the abundant resources it provided.

Conditions mid-2016

The last time that sustained high flows in the River Murray were sufficient to inundate vast areas of lower Murray wetlands and floodplains was in 2010 and 2011. Since 2011 high river flows have mostly been absent so wetlands have relied on the delivery of environmental water to support aquatic life.

Environmental water was delivered to some wetlands in 2015–16 including to Burra Creek North, Neds Corner East and Central, Butlers Creek, Brickworks Billabong, Cardross Lake, Cowanna Billabong, Lakes Powell and Carpul, Nyah and Vinifera floodplains and Lake Hawthorn. This watering achieved a range of positive outcomes for native fish, birds and terrestrial animals.

In 2014–15 Lakes Powell and Carpul received environmental water for the first time since 2011–12. The filling complemented the gains made from the previous watering by improving the condition of black box vegetation that had regenerated around the lakes. The watering also provided habitat and feeding opportunities for many thousands of waterbirds.

At Brickworks Billabong environmental watering supported a population of critically endangered Murray hardyhead. In March 2015, 2,500 Murray hardyhead were translocated to Brickworks Billabong, adding to the existing population. Since that time, watering of the billabong has maintained the condition of ruppia, an aquatic plant that provides habitat for the fish. Monitoring in January 2016 has demonstrated that Murray hardyhead are thriving and breeding in the wetland, with high numbers of adult and juvenile fish present.

Scope of environmental watering

Environmental watering will focus on maintaining and improving vegetation condition, habitat quality and availability throughout the wetlands, floodplains and waterways in the lower Murray region and sometimes on rehabilitating salt-affected wetlands.

Table 1 Potential environmental watering actions and objectives for the lower Murray wetlands

Potential environmental watering

Environmental objectives

Wetland watering

Brickworks Billabong (spring, autumn and top-ups as required to maintain water quality targets and minimum water level)

  • Maintain and improve the condition of aquatic vegetation and water quality for Murray hardyhead

Cardross Lakes (top up as required to maintain water quality targets and minimum water level)

Lake Koorlong (top up as required to maintain water quality targets and minimum water level)

Burra Creek South (winter/spring)

  • Provide productive lake habitat for waterbirds
  • Restore floodplain productivity to maintain resident populations of vertebrate animals including carpet pythons and insectivorous bats
  • Promote emergent and semi-emergent aquatic vegetation

Burra Creek South Proper (spring)

Burra Creek North (winter/spring)

Nyah floodplain (spring/summer)

  • Improve condition and structure of wetland vegetation
  • Provide seasonal feeding and reproductive opportunities for native fish
  • Provide breeding habitat for waterbirds including colonial nesting species
  • Restore floodplain productivity to maintain resident populations of vertebrate animals including carpet pythons, sugar gliders and grey-crowned babblers

Vinifera floodplain (spring/summer)

Liparoo East (winter/spring)

  • Improve condition of the lignum swampy woodland vegetation community and provide habitat for waterbird breeding

Liparoo West (winter/spring)

Woorlong floodplain (winter/spring/autumn)

  • Improve wetland productivity
  • Reinstate submerged and semi-emergent aquatic plants
  • Improve nesting opportunities in flooded lignum surrounding the wetlands
  • Improve the health of surrounding river red gum and black box

Carina Bend (winter/spring)

  • Maintain and improve the health of river red gum, black box and lignum

J1 wetland (winter/spring/autumn)

Yungera wetland (winter/spring/autumn)

Bridge Creek (spring)

Cowanna Billabong (winter/spring)

  • Support fish and birds
  • Increase wetland productivity
  • Provide opportunities for fish to move between wetlands and the River Murray

Butlers Creek (spring/summer)

Neds Corner East and Central (spring)

  • Provide breeding and roosting habitat for colonial waterbirds

Margooya Lagoon (winter/spring/summer)

  • Improve river red gum condition
  • Improve the native fish assemblage of the lagoon
  • Restore submerged aquatic vegetation in the open-water areas of the wetland

Lock 15 wetlands (all year)

  • Improve the productivity of connected riparian zones and wetlands
  • Restore floodplain productivity to maintain resident populations of vertebrate animals including carpet python and insectivorous bats
  • Contribute to the carbon requirements of the River Murray channel ecosystem

Lake Hawthorn (spring, and top-ups as required to maintain water level targets)

  • Restore aquatic vegetation, particularly ruppia
  • Provide habitat for waterbirds

Psyche Bend Lagoon (autumn, winter or spring)

  • Provide freshwater inflows and flushing flows to reduce salinity levels and improve the condition and diversity of wetland vegetation, improving ecological function

Bullock Swamp (autumn, winter or spring)

Outlet Creek (Karadoc Swamp) (spring)

Wetland drying

Kings Billabong, Heywood Lake, Robertsons wetland, Lakes Powell and Carpul, Sandilong Creek and wetland

  • These wetlands will not be actively watered in 2016–17
  • Drying will assist in maintaining a diversity of habitats to support a wide range of wetland-dependent birds and animals and to promote the growth and establishment of vegetation in and surrounding the wetland

Scenario planning

It has been more than five years since the drought-breaking floods of 2011, but conditions have been very dry ever since. Despite the gains made as a result of the widespread floods five years ago, many wetlands require environmental watering. The approach in 2016–17 is to continue recovery and build resilience in fish and wetland plants so they can better endure current and future dry conditions.

The highest-priority wetlands for environmental watering in 2016–17 are Cardross Lakes, Lake Koorlong and Brickworks Billabong, as these sites support the critically endangered Murray hardyhead.

Depending on seasonal conditions and water availability, remaining wetlands are prioritised in line with their recommended watering regimes and considering the condition of the environmental values at each site. If conditions become average or wet, additional wetlands will be watered to mimic conditions that would naturally occur in wetter years. In this way the environmental responses are maximised as plants and animals respond to natural environmental cues.

For some temporary wetlands, the desired wet phase has been achieved consistently in recent years. Some wetlands will not be actively watered in 2016–17 and will be allowed time to dry. This will allow time for plants to germinate and establish, to increase the diversity of habitats available for aquatic plants and animals during the next wet phase. At the same time, the dry phase will provide opportunities for terrestrial animals to access resources within a temporarily dry wetland.

Table 1 Potential environmental watering for lower Murray wetlands under a range of planning scenarios

Planning scenario

Drought

Dry

Average

Wet

Expected catchment conditions

  • No unregulated flows in the River Murray year-round
  • Wetlands rely on environmental water delivery
  • Sustained periods of high flows in the River Murray in late winter and early spring will provide some opportunity for low-lying wetlands to be naturally inundated but most wetlands will still rely on environmental water delivery
  • Lengthy periods of high flows and floods with major spills from storages, resulting in widespread inundation of the floodplain and inundating most wetlands
  • Some reliance on environmental water delivery to achieve target water levels

Potential environmental watering – tier 1 (high priorities)

  • Brickworks Billabong
  • Cardross Lake
  • Lake Koorlong
  • Brickworks Billabong
  • Cardross Lake
  • Lake Koorlong
  • Lock 15 wetlands
  • Lake Hawthorn
  • Burra Creek South
  • Brickworks Billabong
  • Cardross Lake
  • Lake Koorlong
  • Lock 15 wetlands
  • Lake Hawthorn
  • Burra Creek South
  • Nyah floodplain
  • Vinifera floodplain
  • Burra Creek South Proper
  • Neds Corner East and Central
  • Carina Bend
  • Liparoo East
  • Liparoo West
  • Margooya Lagoon
  • Cowanna Billabong
  • Brickworks Billabong
  • Cardross Lake
  • Lake Koorlong
  • Lock 15 wetlands
  • Lake Hawthorn
  • Burra Creek South
  • Nyah floodplain
  • Vinifera floodplain
  • Burra Creek South Proper
  • Neds Corner East and Central
  • Carina Bend
  • Liparoo East
  • Liparoo West
  • Margooya Lagoon
  • Cowanna Billabong
  • Bullock Swamp
  • Psyche Bend Lagoon
  • Woorlong floodplain
  • Burra Creek North
  • Butlers Creek
  • J1 Wetland
  • Yungera Wetland
  • Outlet Creek (Karadoc Swamp)
  • Bridge Creek

Potential environmental watering – tier 2 (additional priorities)

  • Lake Hawthorn
  • Nyah floodplain
  • Vinifera floodplain
  • Carina Bend
  • Liparoo East
  • Liparoo West
  • Margooya Lagoon
  • Cowanna Billabong
  • Bullock Swamp
  • Psyche Bend Lagoon
  • Woorlong floodplain
  • Burra Creek North
  • Butlers Creek

Possible volume of environmental water required to meet objectives1

  • 950 ML (tier 1)
  • 1,500 ML (tier 2)
  • 3,750 ML (tier 1)
  • 6,000 ML (tier 2)
  • 10,200 ML (tier 1)
  • 2,300 ML (tier 2)
  • 15,050 ML (tier 1)

Priority carryover requirements

  • 2,450 ML
  • 9,750 ML
  • 12,500 ML
  • 15,050 ML

1 Environmental water requirements for tier 2 actions are additional to tier 1 requirements.

Risk management

In preparing its seasonal watering proposal, Mallee Catchment Management Authority considered and assessed risks and identified mitigating strategies relating to the implementation of environmental watering. Risks and mitigating actions are continually reassessed by program partners throughout the water year.

Engagement

Waterway managers meet communities on environmental watering regionally, although other program partners also play a role.

In each region of Victoria, community engagement on environmental watering happens when environmental watering objectives and priorities are scoped (long term and annually), when delivering environmental water, and when reporting on environmental watering results.

In the Corangamite region communities are involved in decisions about the Moorabool river and Lower Barwon wetlands. This happens through formal advisory groups including a Moorabool stakeholder advisory and the Lower Barwon community advisory committees.

Who is engaged and how

Recreational users

The Mallee Catchment Management Authority meets with recreational users (such as fishers, bushwalkers, various 'Friends of...' groups) on an ad-hoc basis, where recreational users have an opportunity to communicate their priorities and perspectives. A gap in engagement is anglers as there is not an organised representative group.

Parks Victoria is the land manager for many of the sites that receive environmental water. Parks Victoria notifies recreational users about planned environmental water deliveries and communicates the potential impacts of environmental watering (through their website and on-site public signage).

Environment groups

The Catchment Management Authority engages environment groups (such as the Field Naturalists, Landcare and Birdlife Australia) through direct meetings 2-3 times a year. These groups provide advice, communicate their priorities and are keen to understand environmental watering objectives and outcomes. Some groups also provide information on the outcomes of environmental watering (e.g. through bird surveys.)

Landholders/farmers

The Catchment Management Authority engages the Victorian Farmers Federation, and industry groups such as table grape growers, dried fruit growers, citrus growers and landholders with river frontage or private wetlands.

These groups are engaged on environmental water planning (long term and annual scoping) and environmental water delivery. These groups are also engaged on related projects such as the Sustainable Diversion Limit adjustment proposals.

Traditional Owners

There are representatives from multiple Traditional Owner Nations from the Mallee region on the Murray Lower Darling Rivers Indigenous Nations. The Victorian Environmental Water Holder, the Commonwealth Environmental Water Office and the Murray-Darling Basin Association engage the Murray Lower Darling Rivers Indigenous Nations on strategic (often longer term) issues related to environmental watering.

Through the Catchment Management Authority Indigenous facilitator, individual Aboriginal stakeholders and groups are directly engaged throughout the year via the Catchment Management Authority Aboriginal Reference Group.

Councils

The Catchment Management Authority engages with the Mildura and Swan Hill Rural City Councils quarterly. Councils provide advice on potential community impacts of environmental watering and communicate environmental watering information back to the broader community.

General public

The Catchment Management Authority engages and communicates with the general public about environmental watering via SMS, their website, publications and media releases.