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The Loddon River flows from the Great Dividing Range in the south to the Murray River in the north. Tullaroop Creek is the main tributary in the upper Loddon River system. The middle section of the Loddon River is characterised by many distributary streams and anabranches that carry water away from the river onto the floodplain. The lower Loddon River is joined by Pyramid Creek at Kerang, at which point the Loddon becomes part of the Murray River floodplain.

Two main storages are located on the Loddon River: Cairn Curran and Tullaroop reservoirs, with Lake Laanecoorie used to regulate water from the main storages to the Loddon River. Below Laanecoorie Reservoir, the flow is regulated by the operation of the Bridgewater, Serpentine, Loddon and Kerang weirs.

Water for the environment can be delivered to the Loddon River from Cairn Curran or Tullaroop reservoirs or from the Goulburn system via the Waranga Western Channel, which intersects with the Loddon River at Loddon Weir. Water is provided to Pyramid Creek through releases from Kow Swamp, which receives water diverted from the Murray River at Torrumbarry Weir. Water is diverted from the Loddon River to Serpentine Creek and to the Loddon Valley Irrigation Area to supply agriculture.

The highly regulated nature of the Loddon system provides both challenges and opportunities for effective management of water for the environment. The ability to manipulate the timing of releases at multiple locations provides opportunities to accomplish environmental outcomes at discrete locations. However, coordinating environmental flows and consumptive flows is difficult through the irrigation season, especially when irrigation demand is high or flow in the river is highly variable. This can lead to constraints in the timing and delivery of water for the environment or higher-than-recommended flows above Loddon Weir. The structures used for managing irrigation water form barriers in the waterway, restricting continuity and the ability to achieve outcomes for native fish and possibly platypus.

Traditional Owners
Storage manager
Environmental water holder

System map

Grey river reaches have been included for context. The numbered reaches indicate where relevant environmental flow studies have been undertaken. Coloured reaches can receive environmental water.

Environmental watering objectives in the Loddon River

Fish icon
Increase populations of small and large-bodied native fish

Provide habitat for fish to feed and breed and opportunities for movement between habitats
Landscape icon
Enhance the channel form and features including deep pools and benches

Maintain the condition of suitable substrate, to maintain ecosystem processes

Engage floodrunners, distributary channels, anabranches and backwaters
Platypus icon
Increase the population and recruitment of resident platypus

Maintain a stable rakali (water rat) population in the long term
Plant icon
Maintain the streamside and floodplain vegetation

Maintain and increase the extent of in-stream vegetation
Insect icon
Maintain/increase the diversity and productivity of waterbugs, including biofilms and waterbug functional feeding groups, to drive productive and dynamic food webs
Water icon
Maintain water quality, to support aquatic animals and minimise the risk of blackwater events

Environmental values

The Loddon River system supports platypus, rakali (water rats) and several species of native fish. Streamside vegetation varies in condition depending on the recent water regime, the extent of clearing and historic and current land management practices. Those areas remaining relatively intact support a variety of woodland birds and other native animals. Important plant species across the system include cane grass, tangled lignum, black box and river red gum.

Although fish populations in the Loddon system are affected by the many barriers caused by weirs and reservoirs, a large range of species are still found through the catchment. Native fish are most abundant and diverse in the upper catchment. River blackfish are found in Serpentine Creek and rare Murray-Darling rainbow fish are found in the middle and lower sections of the Loddon River.

The highest-priority reach for environmental watering is from Loddon Weir to Kerang Weir. The reach does not carry irrigation water, and it relies heavily on environmental flows to maintain its environmental condition. Environmental flows to this reach aim to improve the condition of streamside vegetation, maintain water quality and increase the abundance and diversity of native fish. Environmental flows are delivered to the upper Loddon River, Tullaroop Creek and Serpentine Creek to maintain or increase populations of river blackfish and platypus.

Pyramid Creek and the lower Loddon River support large-bodied fish (such as golden perch, Murray cod and silver perch) and are important corridors for fish migration between the Loddon and Murray systems. Engineering works to provide fish passage at the Chute, Box Creek regulator, Kerang Weir, Fish Point Weir and Little Murray Weir on the Little Murray River in recent years have been important in reopening these migration routes. The Arthur Rylah Institute has monitored fish movement and populations in Pyramid Creek and the lower Loddon River since 2017, and results have indicated that the combined Loddon-Pyramid flow is stimulating native fish movement through the fishways.

Traditional Owner cultural values and uses

In planning for environmental flows in the Loddon River, Dja Dja Wurrung, Barapa Barapa and Wamba Wemba and North Central CMA have considered how environmental flows in the Loddon system can be managed to support their respective values and uses.

The Dja Dja Wurrung Traditional Owners have expressed an interest in seeing a return of species to the river that were, within peoples’ living memory, more abundant. This includes species such as platypus, turtles and yabbies. Restoring a natural flow regime and improving water quality are overall cultural aspirations of the Dja Dja Wurrung for management of waterways.

The Barapa Barapa and Wamba Wemba are the Traditional Owners in the northern part of the Loddon catchment, and artefacts of cultural practices are present throughout the Loddon and Pyramid system and its floodplain. The river and floodplain are valued as food and fibre sources and sites of cultural significance such as scar trees, camp sites, meeting places and other important sites.

Social, recreational and economic values and uses

In planning the potential watering actions in Table 1, North Central CMA considered how environmental flows could support values and uses including:

  • water-based recreation (such as canoeing and fishing, kayaking, water skiing and swimming)
  • riverside recreation and amenity (such as camping, cycling, picnicking and walking)
  • community events and tourism (such as local visitation)
  • socio-economic benefits (such as diverters for irrigation, domestic and stock uses).

If the timing or management of planned environmental flows may be modified to align with a community benefit, this is acknowledged in Table 1 with an icon.

Kayak icons

Watering planned to support water sports activities (e.g. skiing competitions)

If possible, North Central CMA will work with Goulburn- Murray Water to manage the delivery of low flow over summer/autumn, which supports optimum conditions for annual water-skiing competitions on the Loddon River at Bridgewater.

Recent conditions

The mid-Loddon catchment had above-average rainfall in July 2019, but the middle and upper Loddon catchments were significantly drier than average during spring and for the first half of summer. Rainfall throughout the Loddon catchment was above average during late summer/autumn 2020, but that did not significantly affect storage levels. Seasonal determinations did not reach 100 percent in the Loddon or Goulburn systems during 2019–20, but carryover, used of allocated water and environmental water transferred into the Loddon system from entitlements in the Goulburn system ensured that enough water was available to deliver all required environmental flows.

Rainfall in the Bet Bet Creek catchment caused spills at Laanecoorie Reservoir and Loddon Weir during July and August 2019, which provided a series of natural freshes and minor overbank flows in the Loddon River below Loddon Weir during early winter. Following the winter spills, flow in the Loddon system returned to the usual regulated conditions for the remainder of the year. Flow in the Loddon River above Loddon Weir, Serpentine Creek and Pyramid Creek exceeded the recommended environmental flow rates at various times during summer/autumn, due to consumptive water deliveries.

The planned environmental watering regime for reach 4 of the Loddon River under dry and average scenarios was entirely achieved in 2019–20. Following the winter high flow, the priority for the year was to continue year-round low flow in the Loddon River and provide summer-autumn freshes to protect water quality and refuge habitat in the Loddon River and Serpentine Creek. Carryover and water transferred into the system made it possible to deliver a spring fresh, combining water from the Loddon River and Pyramid Creek during November 2019.

Monitoring stations continuously monitor temperature and oxygen in reach 4 of the Loddon River. Low oxygen and high water temperatures have occurred in the Loddon River under low flow conditions in previous years, but environmental flows and relatively cool conditions throughout the second half of summer/autumn prevented poor water quality during 2019–20. Environmental water will continue to be used in future, to reduce the risk of dangerously low levels of oxygen.

Scope of environmental watering

Table 1 Potential environmental watering actions and objectives for the Loddon River system

Potential environmental watering action

Functional watering objective

Environmental objective

Loddon River (targeting reach 4)

Summer/autumn fresh (one to three freshes of 50–100 ML/day for three to four days during December to May)1

  • Flush fine sediment from hard surfaces
  • Increase the water level, to promote the growth of fringing emergent macrophytes
  • Increase connectivity to promote the local movement of fish and platypus including juvenile dispersal in autumn
  • Freshen water quality and re-oxygenate pools
Fish iconMountain iconsPlatypus iconPlant iconWater drop icon

Winter/spring high flow (one high flow of 450–750 ML/day for six to 10 days during August to November)2

  • Scour accumulated sediment from pools and scour biofilms
  • Flush accumulated organic matter from the bank and benches, to increase productivity and reduce the risk of a hypoxic blackwater event in summer
  • Increase the wetted area, to promote the recruitment and growth of streamside and emergent vegetation
  • Stimulate native fish movement and breeding
Fish iconMountain iconsInsect iconPlant iconWater drop icon

Summer/autumn low flow (25–50 ML/day during December to May)3

Kayak icons
  • Maintain an adequate depth in pools for aquatic plants and to provide habitat for waterbugs, fish and rakali (water rats)
  • Provide continuous flow through the reach, to maintain water quality
  • Maintain connecting flows to support in-stream and fringing non-woody vegetation
Fish iconPlatypus iconInsect iconPlant iconWater drop icon

Winter/spring low flow (504–100 ML/day during June to November)

  • Increase the water depth for fish, platypus and rakali (water rats) dispersal and to provide foraging habitat
  • Prevent silt and fine sediment settling on submerged wood and other hard surfaces
  • Water the native fringing bank vegetation and prevent the growth of exotic terrestrial plants in the river channel
Fish iconMountain iconsInsect iconPlant iconWater drop iconPlatypus icon

Autumn high flow (one high flow of 400 ML/ day for six to 10 days during March to May)

  • Trigger and facilitate the upstream movement of golden perch, silver perch and Murray cod older than one year
  • Facilitate platypus dispersal
Fish iconPlatypus icon

Serpentine Creek5

Summer/autumn fresh (one to three freshes of 30–40 ML/day for one to three days during December to May)

  • Maintain the channel form by inundating benches
  • Flush fine sediment and scour biofilms, to replenish the food supply
  • Transport organic matter that has accumulated in the channel
  • Provide flow variability to maintain the diversity of fringing vegetation
  • Wet exposed woody habitat for waterbugs and provide a sufficient depth of water and variability of flow to maintain microbial biofilms
  • Freshen water quality by diluting salt and oxygenating pools

Fish iconMountain iconsInsect iconWater drop iconPlatypus icon

Winter/spring fresh (one fresh of 40–150 ML/ day for two days during August to November)

  • Maintain the channel form and scour pools
  • Provide connectivity for fish and waterbugs to access different habitat areas
  • Transport organic matter that has accumulated in the channel, to increase productivity and reduce the risk of a hypoxic blackwater event in summer
  • Provide a cue for adult platypus to construct burrows above the higher water level
Fish iconMountain iconsWater drop iconPlatypus iconInsect icon

Summer/autumn low flow (10–20 ML/day during December to May)

  • Provide flow variability to prevent notching of riverbanks
  • Provide connectivity between pools to allow the dispersal of small-to- medium-bodied native fish
  • Wet exposed roots, leaf packs and woody debris, to provide habitat for aquatic animals
  • Provide sufficient flow to maintain water quality by oxygenating pools
  • Maintain foraging habitat for platypus
  • Maintain the wetted area to support in-stream aquatic vegetation (such as water ribbons, eel weed and milfoil)
Fish iconPlant iconWater drop iconInsect iconMountain icons

Winter/spring low flow (20–30 ML/day during June to November)

  • Maintain spawning habitat for native fish
  • Wet exposed roots, woody debris, emergent vegetation and leaf packs, to provide habitat for aquatic animals
  • Maintain water quality by preventing stagnation
  • Provide flow variability, to prevent notching of riverbanks and maintain diversity of fringing vegetation
  • Provide a sufficient depth of water and variability of flow to maintain microbial biofilms
Fish iconPlant iconWater drop iconInsect icon

Pyramid Creek and Loddon River (reach 5)

Spring high flow (one high flow of 700 ML/day for 10 days during September to October)

  • Trigger the migration, spawning and recruitment of native fish species including Murray cod
  • Maintain connectivity between habitats and improve water quality
Fish iconWater drop icon

Autumn/winter low flow (90–200 ML/day during May to August)

  • Maintain connectivity between pools and provide habitat for fish and waterbugs outside of the irrigation season
  • Improve water quality by reducing salinity levels
  • Enhance the wetted area to maintain and promote the growth of fringing emergent (non-woody) vegetation along the lower banks of the channel
  • Redistribute fine sediment on benches and bars
Fish iconMountain iconsPlant iconInsect iconWater drop icon

Autumn high flow (up to one high flow of 700–900 ML/day for 10 days during March to May)

  • Trigger the migration, spawning and recruitment of native fish species including Murray cod
  • Facilitate the upstream movement of golden perch, silver perch and Murray cod older than one year
  • Maintain connectivity between habitats and improve water quality
  • Facilitate platypus dispersal
Fish iconPlatypus iconWater drop icon

1 The recommended magnitude and duration may be increased if needed to prevent a decline in oxygen levels.

2 Due to the potential wetting of private land, environmental flows above 450 ML per day in reach 4 will not be provided without the agreement of landholders who could potentially be affected.

3 Recommended magnitude may be increased if needed to prevent adverse declines in oxygen levels.

4 Winter/spring low flow of 50 ML per day is below the passing flow magnitude and will result in the VEWH banking passing flows savings, for use in other potential watering actions.

5 Flows in Serpentine Creek will be allowed to either return to the Loddon River or continue down Pennyroyal/Bannacher Creek or Nine Mile Creek with the agreement of landholders.

Engagement

Table 2 shows the partners and stakeholder organisations with which North Central CMA engaged when preparing their seasonal watering proposals.

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 North Central Regional Catchment Strategy and North Central  Waterway Strategy.

Table 2 Partners and stakeholders engaged in developing the Loddon system seasonal watering proposal

Partner and stakeholder engagement
  • Department of Environment, Land, Water and Planning (land manager)
  • Individual landholders
  • VRFish
  • Field and Game Australia
  • Dja Dja Wurrung Clans Aboriginal Corporation
  • Barapa Barapa Traditional Owners
  • Wemba Wemba Traditional Owners

Page last updated: 27/02/20