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The system has long been of a place of high significance to the Wadawurrung Traditional Owners. Paleert Tjaara Dja –Let’s make Country good together 2020 – 2030 Wadawurrung Country Plan acknowledges the special place the system has in their Dreaming: ‘The chain of ponds from the Barwon River to Reedy Lake, Hospital Lake, Lake Connewarre and Estuary Bay is connected through water and our Connewarre (Black Swan) Dreaming’.

Water for the environment can be used to manage water levels in Reedy Lake and Hospital Swamps, which connect to the Barwon River. The environmental entitlement for the lower Barwon wetlands does not provide access to water held in storage. Instead, it allows water to be diverted from the Barwon River into Reedy Lake and Hospital Swamps when river levels are above 0.7 m AHD (Australian Height Datum). High water levels in the Barwon River can also result in the natural wetting of the wetlands.

Traditional Owners
Environmental water holder

System map

Environmental watering objectives in the Lower Barwon wetlands

Fish icon
Provide habitat for fish breeding and growth and improved conditions for migration and dispersal, when wetlands are connected to the Barwon River
Soil icon
Provide varying water levels and conditions to promote soil salinisation, to support the persistence and growth of threatened saltdependent ecological vegetation communities
Plant icon
Maintain the high diversity of ecological vegetation communities in the wetlands Increase the growth and extent of coastal saltmarsh, herbfields and lignum shrubland ecological vegetation communities
Insect icon
Maintain and improve the waterbug population and its biomass
Water icon
Maintain nutrient cycling and improve lake productivity

Provide flushing inflows to remove accumulated salts

Maintain surface water and groundwater interactions
bird icon
Provide suitable foraging habitat including mud flats and shallow water for wading birds, and refuge for waterbirds and shorebirds

Environmental values

Reedy Lake and Hospital Swamps form part of the internationally recognised Port Phillip Bay (Western Shoreline) and Bellarine Peninsula Ramsar site, which is used by many thousands of migratory birds from around the world. The wetlands support 47 known threatened plant and animal species and communities. These include some of Victoria’s rarest species (such as the brolga, orange-bellied parrot, Australasian bittern, growling grass frog, Australian grayling and dwarf galaxias) and subtropical and temperate coastal saltmarsh communities. Reedy Lake supports a range of vegetation communities including coastal saltmarsh, herbfields and reed beds.

Reedy Lake was naturally a partly ephemeral system, but river regulation meant the lake was permanently wetted from the 1970s until 2016. This long-term wetting resulted in a decline in biodiversity. The full water levels reduced the extent and diversity of vegetation communities including coastal saltmarsh, and reduced the availability of shallow wading habitat which in turn has resulted in lower waterbird diversity.

In 2016-17, Corangamite CMA and the VEWH implemented a four-year watering regime trial at Reedy Lake to reinstate a more natural wetting and drying cycle. The 2019-20 water year was the final year of the trial — three years of partial drying and one year completely full — and a review of the recommended regime was completed in 2020. The review’s recommendations have informed the 2021-22 watering actions and future directions.

Hospital Swamps is made up of five wetland basins that support important ecological processes and significant ecological values including large areas of threatened coastal saltmarsh and diverse waterbird communities. Vegetation communities in Hospital Swamps have remained largely unchanged over time due to the maintenance of natural wetting and drying cycles.

Traditional Owner cultural values and uses

Corangamite CMA worked with Wadawurrung Traditional Owners during the development of environmental watering plans for the lower Barwon wetlands, as part of an ongoing conversation to ensure Wadawurrung knowledge and culture is incorporated into decision-making, and that watering requirements for culturally significant species are maintained.

The Wadawurrung have identified cultural values which apply to all waterways within Wadawurrung Country. Values that have been identified in the lower Barwon wetlands include:

  • culturally significant wetland species such as Porronggitj (brolga), Toolim (black duck), Kunuwarra (black swan), Buniya
  • (eel), Tark (common reed) and Bal-yan (bull rush)
  • recognition of wetlands as meeting, ceremony and trade places
  • maintaining water holes and refuge pools
  • maintaining access to culturally important story places and ceremonial places
  • protection of artefact sites
  • use of appropriate Wadawurrung language for places of cultural importance
  • increased opportunities for the Wadawurrung to be involved in monitoring and evaluation activities
  • including the Wadawurrung in all communication around releases of water for the environment and other wetland-related activities.

Social, recreational and economic values and uses

In planning the potential watering actions in Table 1, Corangamite CMA consulted widely with stakeholders to ensure it considered social, cultural and economic matters relevant to water management in the lower Barwon wetlands. Opportunities for social, recreational and economic values and uses are incorporated into planning and watering decisions if they do not compromise environmental outcomes.

Expert advice (such as a flow ecology study and the 2020 Lower Barwon Review) emphasised that the entire recommended watering regime — filling the wetlands and allowing water levels to draw down at the right times — must be implemented to improve biodiversity and protect the long-term health of the wetlands, so it may not be possible to meet some community expectations at all times (such as keeping the wetlands permanently full).

However, Corangamite CMA plans to ensure management of water levels in the wetlands can meet ecological requirements and also support a range of values and uses where possible including:

  • water-based recreation (such as boating, duck hunting and fishing)
  • riverside recreation and amenity (such as birdwatching and spending time outdoors)
  • community events and tourism (such as community events and Traditional Owner events)
  • socio-economic benefits (such as commercial fishing).

Corangamite CMA works with its community advisory group and stakeholders and seeks to balance these interests where possible, while maintaining the overall health of the wetlands to help sustain these activities into the future.

Recent conditions

Rainfall across the lower Barwon River catchment in 2020-21 was mostly above the long-term average. High-flow events in the Barwon River during spring and summer provided natural inflows to Reedy Lake and Hospital Swamps.

The Corangamite CMA had planned to draw down water levels in Reedy Lake from early summer 2020-21, to provide the recommended drying cycle and associated effects to maintain the character of the wetland as per the Lower Barwon Review, but the drawdown was delayed by the natural inflows and an associated bird breeding event. A partial drawdown commenced in February 2021, once the breeding birds had fledged their chicks. The planned drawdown at Hospital Swamps was also delayed by natural inflows from the Barwon River and stormwater inflows from a neighbouring development site.

The late drawdown in both wetlands meant the target low water level of 0.3 m AHD could not be met in Reedy Lake, and it was achieved much later than planned in Hospital Swamps. The incomplete and delayed drawdowns reduced the quantity of shallow foraging habitat for wading waterbirds and limited growing conditions for coastal salt marsh vegetation. The wetter-than-average conditions in 2020-21 are a natural year-to-year variation, and they are not expected to compromise the long-term environmental objectives for the site provided the lakes can draw down in coming years.

Scope of environmental watering

Table 1 Potential environmental watering actions, expected watering effects and associated environmental objectives for the lower Barwon wetlands

Potential environmental watering action

Expected watering effects

Environmental objectives

Reedy Lake

Autumn/winter/spring fill (April/early May to November) (targeting 0.8m AHD)

  • Maintain a mosaic of water depths and resources across the wetland to support waterbird breeding events
  • Inundate fringing wetland vegetation to provide foraging habitat for waterbirds
  • Maintain a sufficient depth of water around wetland vegetation to provide fish breeding habitat
  • Temporarily inundate the outer edges of the wetland to initiate growth and recruitment of diverse vegetation communities while permanently inundating the inner wetland vegetation communities
  • Allow fish to move between the river, lake and estuary
  • Stimulate waterbug communities to breed for waterbird feeding
  • Dilute soil and surface water salts and initiate the decomposition of organic matter
Fish iconPlant icon  Heron icon
Summer/autumn drawdown (December to April/early May, top-up or drawdown as required) (targeting 0.3m AHD)
  • Lower the water level by natural evaporation and assisted drawdown (if required and as informed by waterbird monitoring) to dry out wetland fringing vegetation, to reduce potential waterlogging of saltmarsh communities to support germination
  • Expose mudflats and margins to provide feeding habitat for wading/ migratory waterbirds and frogs
  • Manage reed colonisation of low-lying areas by allowing drying and saline groundwater intrusion to reduce growth
  • Support a drying phase for vegetation communities that require drying to grow and recruit
  • Reduce water levels to restrict carp movement and access to habitat
  • Allow vegetation to decay and soils to oxidise and release nutrients, to improve lake productivity and maintain biogeochemical processes
  • Enable surface water/groundwater interaction by allowing saline groundwater to discharge to the wetland bed

Fish iconPlant iconHeron iconJigsaw icon

Hospital Swamps

Autumn/winter/spring fill (May to November) (targeting 0.5m AHD)

  • Maintain a mosaic of water depths and resources across the wetland and inundate various vegetation communities and create nesting, breeding and feeding opportunities for waterbirds, fish and waterbugs
  • Increase water levels to trigger fish spawning and waterbird breeding:
    • high water levels will allow fish to access the wetland from the river
    • more freshwater will dilute the salt in the soil and dilute surface water over the winter
  • Inundate the outer edges and margins to initiate the growth and maintain the condition of important wetland vegetation communities

Fish iconPlant iconHeron iconInsect iconWater drop icon

Summer/autumn drawdown (December to April) (by natural evaporation and assisted drawdown, if required) (targeting 0.1-0.3m AHD)

  • Lower the water level by natural evaporation and assisted drawdown (if required and as informed by waterbird monitoring if available) to dryout the wetland fringing vegetation and expose mudflats and margins to support feeding by wading/migratory waterbirds and frogs
  • Manage reed colonisation in low-lying areas by allowing drying and saline groundwater intrusion to reduce growth
  • Support a drying phase for vegetation communities that require drying to grow and recruit
  • Reduce water levels to restrict carp movement and access to habitat
  • Allow vegetation to decay and soils to oxidise and release nutrients, to improve lake productivity and maintain biogeochemical processes
  • Enable surface water/groundwater interaction by allowing saline groundwater to discharge to the wetland bed

Fish iconPlant iconHeron iconJigsaw icon

Engagement

Table 2 shows the partners, stakeholder organisations and individuals with which Corangamite CMA engaged when preparing the lower Barwon wetlands seasonal watering proposal.

Seasonal watering proposals are informed by longer-term regional catchment strategies, regional waterway strategies, environmental flow studies, water management plans and other studies. These incorporate a range of environmental, cultural, social and economic perspectives and longerterm integrated catchment and waterway management objectives. For further details, refer to the Corangamite Regional Catchment Strategy and the Corangamite Waterway Strategy.

Over the last six years, the Corangamite CMA has consulted extensively about the planned watering regimes for Reedy Lake and Hospital Swamps with diverse stakeholders and interest groups representing over 1,500 people. These people have been involved in developing the original environmental flows study and in subsequent scientific work about ecological risks, vegetation monitoring, alternative management approaches and infrastructure operations. The results of this work show that lowering water levels at Reedy Lake is the only feasible management practice that will mitigate threats to the ecological health of the wetland and ensure all user groups can continue to use the system in future.

Table 2 Partners and stakeholders engaged in developing the lower Barwon wetlands seasonal watering proposal

Partner and stakeholder engagement
  • Community members on the Lower Barwon Community Advisory Committee
  • Members of the Lower Barwon Review Project Advisory Group
  • Environment Victoria
  • Geelong Environment Council
  • Geelong Field Naturalists Club
  • Barwon Water
  • Department of Environment, Land, Water and Planning
  • Parks Victoria
  • Southern Rural Water
  • Greater Geelong City Council
  • Victorian Fisheries Authority
  • Landholders
  • Farmers
  • Commercial eel fishers
  • Geelong Field and Game
  • Geelong Gun and Rod Association
  • VR Fish
  • Lower Barwon Review 2020 Expert Review Panel
  • Wathaurung Aboriginal Corporation

Page last updated: 22/01/21