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Two main storages are located on the Loddon River: Cairn Curran and Tullaroop reservoirs, with Laanecoorie Reservoir 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, restrict flow reliability and create barriers to aquatic animal movement throughout the river – impacting 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
Connected icon
Maintain productive and dynamic food webs

Maintain/increase the diversity and abundance of biofilms
Plant icon
Maintain the streamside and floodplain vegetation

Maintain and increase the extent of in-stream vegetation
Insect icon
Maintain/increase the diversity and abundance of waterbugs and waterbug functional feeding groups
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 system, Dja Dja Wurrung, Barapa Barapa and Wemba Wamba and North Central CMA have considered how environmental flows in the Loddon system can be managed to support their respective values and uses.

Environmental water management assists with preservation of historical and contemporary values held highly by the Dja Dja Wurrung. This includes promoting a sense of place and spiritual connection. The Kapa Gatjin and North Central CMA have been working together to identify opportunities and sites where water for the environment can support the Dja Dja Wurrung’s aspirations for the Loddon River.

The Barapa Barapa and Wemba Wamba 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.

In early 2021, the Barapa Barapa Wemba Wamba Water for Country Steering Committee joined North Central CMA staff on Country to discuss the cultural values of the river and floodplain and how environmental water can contribute to achieving cultural objectives. The Steering Committee members emphasised the importance of supporting fish populations, particularly Murray cod and golden perch. The Traditional Owners also identified evidence of occupation such as clay balls and mussel shells in Sheepwash Creek, supporting similar observations in the Pennyroyal Creek- Bannacher Creek network on a previous field visit and providing evidence that environmental flows can help the distribution and health of plants and tubers for food and medicine.

These values will be supported in 2021-22 through flows that are designed to support food and fibre species of cultural value and to facilitate cultural activities.

Barapa Barapa Traditional Owners have also communicated their cultural objectives for the Loddon River and other waterways in the Barapa Barapa Healthy Country Plan. Objectives that relate to the Loddon River system include:

  • all wetlands surrounding the Murray River, Gunbower Forest, Loddon River and associated lakes have good plant life and healthy native fish (cod and yellow belly), mussels and turtle populations by 2033
  • by 2033, the Murray, Gunbower, Loddon and associated lakes will have enough water. Water quality is improving and water is clear for most of the year in good years
  • Barapa people are actively involved in water management
  • reduce the number of major fish and plant deaths from toxic blackwater events to improve water quality.

Social, recreational and economic values and uses

In planning the potential watering actions in Table 5.7.1, North Central CMA considered how environmental flows could support values and uses including:

  • water-based recreation (such as fishing, powered and non-powered boating, water skiing and water sports)
  • riverside recreation and amenity (such as birdwatching, bushwalking, camping and cycling)
  • community events and tourism (such as water skiing competitions at Bridgewater and associated visitation)
  • socio-economic benefits (such as diverters for domestic and stock uses, local and regional economic benefits from increased visitation and ecosystem services [such as carbon storage, groundwater recharge and nutrient recycling]).

If the timing or management of planned environmental flows may be modified to align with a community benefit, this is acknowledged in Table 5.7.1 with the following 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 rates and the timing of freshes over summer/autumn, to support optimum conditions for annual water skiing competitions at Bridgewater weir pool, where possible.

Recent conditions

Despite dry conditions in July, rainfall and temperatures in the Loddon catchment were close to the long-term average throughout most of 2020-21. Inflows to major storages in autumn 2020 resulted in opening season allocations of 35 percent for high-reliability water shares in the Loddon and Goulburn systems, which was higher than the previous year. Allocations increased regularly through spring and reached 100 percent in mid-November. No low-reliability water share allocation was issued in 2020-21.

A small natural fresh occurred in September 2020 and again in February 2021, but otherwise there were relatively few natural high-flow events in the Loddon River system in 2020-21. Low flow was delivered to all reaches throughout the year using mandated passing flows, environmental water or a combination of both. Water for the environment was used to deliver spring freshes in the Loddon River, Serpentine Creek and Pyramid Creek. The Loddon River and Pyramid Creek freshes were coordinated to provide a higher flow at Kerang Weir, to cue native fish to move into the system from the Murray River. Water for the environment was also used to deliver two summer/autumn freshes in the Loddon River; a third summer/autumn fresh occurred naturally in February.

In 2020-21, water for the environment in the Loddon system was managed initially in line with a dry climate scenario, shifting to an average climate scenario from spring onwards. Most planned watering actions for the Loddon River and Pyramid Creek were achieved. The only event that was not delivered to these systems was a higher autumn flow that aimed to facilitate platypus and native fish migration. The lack of this flow is not considered a major problem, because a large autumn flow occurred naturally in April 2020. The potential flooding of private land at the end of Serpentine Creek prevented the delivery of planned summer/autumn freshes, and the winter/spring low flow in Serpentine Creek was delivered at less than the recommended magnitude at times during 2020-21. The North Central CMA, storage manager and the VEWH will undertake to resolve this issue in 2021-22 to allow a wider range of watering actions to be delivered in future.

Results of fish monitoring surveys conducted by the Arthur Rylah Institute as part of the Victorian Environmental Flows Monitoring and Assessment Program in 2020-21 indicated that native fish are moving and using fishways in response to medium-to-high environmental flows in the Loddon system. This information resulted in the recommended low-flow magnitude in Pyramid Creek and the lower Loddon River increasing, compared to previous years.

Scope of environmental watering

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

Potential environmental watering action

Expected watering effects

Environmental objective

Loddon River (targeting reach 4)

Winter/spring low flow (50-100 ML/day during June to November)1

  • Increase the water depth for fish, platypus and rakali (water rat) dispersal (especially for male juvenile platypus to colonise new breeding territory in winter) and to provide foraging habitat
  • Prevent silt and fine sediment settling on submerged wood and other hard surfaces
  • Inundate a variety of habitats, to increase the growth of biofilms and support waterbug productivity
  • Water the native fringing bank vegetation, to support seed germination and growth and prevent the encroachment of exotic terrestrial plants in the river channel
Fish iconMountain iconsPlatypus iconPlant iconJigsaw icon

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

  • Provide sufficient velocity to 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
  • Wet the banks to promote the recruitment and growth of streamside and emergent vegetation
  • Stimulate native fish movement and breeding
Fish iconMountain iconsInsect iconJigsaw iconPlant iconWater drop icon

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

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
  • Wet the banks and shallow riffles, to support the growth of in-stream and fringing non-woody vegetation
Fish iconPlatypus iconInsect iconPlant iconWater drop icon

Summer/autumn freshes (three to four2 freshes of 50-100 ML/day for three days during December to May)

Kayak icons
  • Increase the water level, to promote seed germination and the growth of fringing emergent macrophytes
  • Increase connectivity between deep pools to promote the local movement of fish and to prompt the dispersal of juvenile platypus in autumn
  • Generate sufficient force to flush fine sediment and old biofilms from submerged wood and other hard surfaces, promoting the growth of new biofilms and increasing waterbug productivity
  • Freshen water quality and reoxygenate pools
Fish iconMountain iconsInsect iconPlant iconWater drop iconPlatypus icon

Autumn high flow (one high flow of 400 ML/day for six days3 during March to May)3

  • Trigger and facilitate the upstream movement of golden perch, silver perch and Murray cod older than one year
  • Facilitate the dispersal of juvenile platypus
  • Generate sufficient force to flush fine sediment and old biofilms from submerged wood and other hard surfaces, promoting the growth of new biofilms and increasing waterbug productivity
Fish iconMountain iconsInsect iconPlant iconJigsaw iconPlatypus icon

Serpentine Creek (targeting reach 1)4

Winter/spring low flow (20- 50 ML/day5 during June to November)

    • Maintain habitat for native fish and facilitate movement for aquatic animals
    • 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 maintain the diversity of fringing vegetation
    • Provide a sufficient depth of water and variability of flow to maintain microbial biofilms

Fish iconJigsaw iconInsect iconPlant iconWater drop iconPlatypus icon

Winter/spring fresh (one fresh of 40-150 ML/day5 for two days during August to November)

  • Maintain the channel form and scour pools (an augmented response is expected when delivered at 120-150 ML/day)
  • Provide connectivity for fish and waterbugs to access different habitat areas, supporting a diversity of functional feeding groups
  • Transport organic matter that has accumulated in the channel, to increase the breakdown of organic matter in winter/spring and reduce the risk of a hypoxic blackwater event in summer (an augmented response is expected when delivered at 120-150 ML/day)
  • Encourage female platypus to select nesting burrows higher up the bank (when delivered at 120-150 ML/day) to reduce the risk of higher flow later in the year flooding burrows when juveniles are present
Fish iconMountain iconsWater drop iconPlatypus iconInsect icon

Summer/autumn low flow (10-20 ML/day5 during December to May)

  • 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 icon

Summer/autumn freshes (three freshes of 40 ML/ day5 for two days during December to May)

  • Maintain the channel form by inundating benches
  • Generate sufficient force to flush fine sediment and old biofilms from submerged wood and other hard surfaces, to increase productivity and replenish the food supply for aquatic animals
  • Transport organic matter that has accumulated in the channel providing carbon and nutrients downstream
  • Provide flow variability to maintain the diversity of fringing vegetation such as emergent macrophytes
  • Freshen water quality by diluting salt and re-oxygenate pools
Fish iconPlant iconWater drop iconInsect iconMountain iconsJigsaw iconPlatypus icon

Pyramid Creek (targeting Box Creek regulator) and lower Loddon River (targeting Kerang Weir)

Year-round low flow (90- 300 ML/day at Box Creek regulator)

  • Maintain connectivity between pools and provide habitat for aquatic animals
  • 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
Fish iconPlatypus iconPlant iconInsect iconWater drop icon

Winter/spring high flow (one high flow of 700 ML/ day at Kerang Weir for 10 days)6

  • Trigger the migration, spawning and recruitment of native fish species including Murray cod
  • Maintain connectivity between habitats and improve water quality
  • Provide sufficient energy to flush accumulated sediment from pools and substrates
Fish iconMountain iconsWater drop icon

Autumn high flow (one high flow of 700 ML/day7 at Kerang Weir for six days3 during March to April)6

  • Trigger and 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 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.

2 A fourth summer/autumn fresh may be delivered under drought or dry climate scenarios. The recommended magnitude and duration may be increased if needed, to prevent a decline in oxygen levels.

3 The peak magnitude of this event is planned to be delivered for six days, but there is an extended, 10-day ramp-down period.

4 Flow in Serpentine Creek may be allowed to either return to the Loddon River or continue down Pennyroyal and Bannacher creeks or Nine Mile Creek with the agreement of landholders.

5 Flow delivered from Serpentine Weir may be restricted to manage end-of-system outfalls, to avoid third-party impacts, until an alternate solution is determined.

6 Winter/spring and autumn freshes are planned to occur at the same time in the Loddon River and Pyramid Creek, with the peak timed to meet at Kerang Weir. 700 ML/day is the total combined target at Kerang Weir.

7 The autumn high flow may be delivered at a reduced rate under seasonal or operational conditions, which could heighten the risk of third-party impacts.

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
  • Commonwealth Environmental Water Office
  • Goulburn-Murray Water
  • Department of Environment, Land, Water and Planning
  • Individual landholders and community members
  • Barapa Barapa Traditional Owners
  • Dja Dja Wurrung Clans Aboriginal Corporation
  • Wemba Wamba Traditional Owners

Page last updated: 22/01/21