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The Loddon River flows north from the Great Dividing Range in central Victoria to the River Murray (see map below). The major storages are Cairn Curran, Tullaroop and Laanecoorie reservoirs.

Environmental water can be delivered to the Loddon River from the Loddon or the Goulburn systems due to the Loddon River's connection with the Goulburn system via the Waranga western channel. Water is provided to Pyramid Creek from the Murray system via the national channel. Water is diverted from the Loddon River to Serpentine Creek, mainly for irrigation.

The highest-priority reach for environmental watering is from Loddon Weir to Kerang Weir where there are good opportunities to improve vegetation condition and fish abundance and because this reach doesn't receive any flows for irrigation deliveries. The upper Loddon River and Tullaroop Creek are also a priority because of the river blackfish and platypus that live there.

Due to the significant modifications to the natural waterways for irrigation supply, the water distribution system in the Loddon is very complicated. This provides both challenges and opportunities for effective environmental water management. It is possible to manipulate the timing and location of releases to accomplish environmental outcomes throughout the system. As experience in managing newly updated environmental flow recommendations is gained in coming years, we expect that water use efficiency and effectiveness will improve.

System map

Loddon System
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
Protect and boost populations of native fish by providing flows for them to move upstream and downstream and encourage spawning
Plant icon
Maintain river red gum, tea tree and lignum and provide opportunities for new plants to germinate and grow
Platypus icon
Create opportunities for young platypus to disperse to new, high-quality habitat so they are not competing for space and food and become more resilient to threats (such as predation from foxes)

Environmental values

The Loddon River system contains platypus, river blackfish and lots of small native fish (such as flat-headed gudgeon, Australian smelt and mountain galaxias). While fish are most abundant and diverse in the upper reaches of the Loddon River and in Tullaroop Creek, river blackfish are also found in Serpentine Creek and Murray–Darling rainbow fish are in the middle and lower sections of the Loddon River. Pyramid Creek supports large-bodied fish (such as golden perch) and is an important pathway for fish migration to and from the Loddon and Murray systems.

The condition of streamside plants varies from bad to good depending on several factors such as the recent water regime, the extent of clearing that has occurred, adjacent land use practices and weed invasions. Woodland birds and other native animals are abundant where there is good-quality riparian vegetation providing diverse habitats.

Social and economic values

The Loddon River supplies the Boort irrigation district and is essential for prosperity in the region. Murray cod and golden perch are stocked in the Loddon River and are an important recreational fishing species. Bridgewater on Loddon attracts visitors to waterskiing and triathlon competitions held on the Loddon River. The Loddon River is also rich in Aboriginal heritage, and there are scarred trees and shell middens commonly found throughout the system.

Conditions mid-2016

The Loddon River system was extremely dry for the entire 2015–16 year and inflows to Loddon system storages were close to the lowest ever recorded.

Due to the effects of dams, weirs and river regulation, the plants and animals in the Loddon system have adapted to a near-permanent flow regime. It is natural for rivers like the Loddon to stop flowing in very low rainfall years, but it is also important to protect the aquatic life in the river during dry times so that it can quickly rebound when conditions improve.

In 2015–16 the combined volume in Cairn Curran and Tullaroop reservoirs fell below the trigger point where Loddon River passing flows are lowered to protect water supplies. Additional environmental water releases were made to maintain minimum low flows through the river and protect the gains made in fish populations and plant condition in previous years. Improvements in the condition of aquatic plants have occurred in the last few years.

Plants such as water ribbons, eel grass and milfoil have substantially increased, particularly in reaches upstream of Laanecoorie Reservoir.

Higher flows were released to the upper and lower reaches of the Loddon River in spring and summer to improve water quality and provide a chance for fish and platypus to move and feed. These flows also gave the streamside plants (including river red gums, shrubs and grasses) a drink, which stabilises the banks and improves habitat for birds, lizards and other animals that live near the river.

Scope of environmental watering

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

Potential environmental watering

Environmental objectives

Loddon River (reach 1)

Year-round low flows (10 to 80 ML/day year-round)

  • Allow fish movement through the reach and maintain depth of pool habitat for native fish
  • Facilitate long-distance movement of male platypus in the August–October breeding season
  • Maintain suitable water quality in pools in summer

Summer/autumn freshes (up to 3 freshes of 35–80 ML/day for 1–3 days in December–May)

  • Promote movement of fish so they access alternate habitats
  • Wash organic matter into the stream to drive the aquatic food webs
  • Mix and re-oxygenate pools and dilute concentrated salt
  • Inundate lower banks to wet the soil and promote the establishment, growth and survival of sedges and reeds

Winter/spring freshes (1–2 freshes of more than 400 ML/day for 1–5 days in July–October)

  • Promote recruitment of riparian vegetation
  • Stimulate movement of native fish and enhance Murray cod breeding
  • Flush accumulated leaf litter from banks and low benches into the channel to drive aquatic food webs

Tullaroop Creek (reach 2)

Year-round low flows (5–40 ML/day year-round)

  • Allow fish movement through the reach and maintain the depth of pool habitat for river blackfish
  • Facilitate long-distance movement of male platypus in the August–October breeding season
  • Maintain suitable water quality in pools in summer

Summer/autumn freshes (up to 3 freshes of 30–40 ML/day for 1–3 days in December–May)

  • Promote movement of fish so they access alternate habitats
  • Wash organic matter into the stream to drive aquatic food webs
  • Mix and re-oxygenate pools and dilute concentrated salt
  • Inundate lower banks to wet the soil and promote the establishment, growth and survival of sedges and reeds

Winter/spring freshes (1–2 freshes of more than 200 ML/day for 1–5 days in July–October)

  • Promote recruitment of riparian vegetation
  • Stimulate movement of native fish and enhance Murray cod breeding
  • Flush accumulated leaf litter from banks and low benches into the channel to drive aquatic food webs

Loddon River reach 3 a and 3b

Low flows (1–5 ML/day year-round) under a drought scenario

  • Maintain adequate water quality and drought refuge habitat for native fish, platypus and waterbugs in reaches 1, 2 and 3
  • Protect aquatic vegetation in reaches 1, 2 and 3

Trigger-based freshes (freshes of 30 ML/day for 7 days) under a drought scenario

Loddon River (reach 4)

Summer/autumn low flows (25–50 ML/day in December–May)

  • Continuous flows through the reach to maintain water quality in pools
  • Maintain pool habitat for large-bodied fish (such as Murray cod, golden perch and bony herring)
  • Maintain shallow water habitats for small-bodied fish (such as flat-headed gudgeon)
  • Maintain connecting flows for aquatic plant propagules to disperse and establish

Summer/autumn freshes (up to 3 freshes 50–100 ML/day for 3–4 days in December–May)

  • Facilitate upstream movement of juvenile golden perch
  • Wet submerged wood and flush silt and biofilms from hard surfaces to promote new biofilm growth and increase waterbug populations
  • Facilitate downstream dispersal of platypus in April–May

Spring high flow (one high flow of 450–750 ML/day with a 7-day peak in September–October)1

  • Inundate banks, floodrunners and low-lying parts of the floodplain to promote growth and recruitment of riparian vegetation
  • Provide a cue for golden perch and Murray cod to migrate and breed
  • Flush leaf litter and organic material from the banks to drive aquatic food webs

Autumn high flow (1 high flow of 400 ML/day with a 6-day peak in April–May)

  • Provide a cue for fish from the River Murray to swim upstream and colonise the Loddon River
  • Help juvenile platypus disperse from the upper Loddon River to the lower Loddon River and the River Murray

Winter/spring low flows (50–100 ML/day in June–November)

  • Prevent terrestrial plants from encroaching into the channel
  • Assist the growth of fringing vegetation (such as sedges and reeds)
  • Provide foraging and resting habitat for platypus

Serpentine Creek

Summer/autumn freshes (2 freshes of 40 ML/day for 1–3 days in December–May)

  • Allow fish, platypus and turtle to move through the reach
  • Inundate benches and fringing vegetation
  • Inundate wood and promote biofilm development
  • Maintain water quality and prevent low dissolved oxygen conditions

Winter fresh (1 fresh of 120–150 ML/day for 1 day in July–August)

  • Flush organic material from banks to reduce risk of blackwater in summer
  • Inundate benches and water-fringing vegetation
  • Inundate wood and scour biofilms from the streambed
  • Inundate benches to provide breeding habitat for frogs

Pyramid Creek and Loddon River reach 52

Spring high flow (1 high flow of 900 ML/day for 10 days in September to November)

  • Trigger and facilitate fish movement and breeding, particularly golden perch and silver perch
  • Recruitment and maintenance of riparian vegetation
  • Flush accumulated leaf litter from banks to provide carbon for aquatic foodwebs

Autumn high flow (1 high flow of 900 ML/day for 10 days in March–May)

  • Trigger and facilitate movement of juvenile fish

1 Due to potential inundation of private land, environmental flows above 450 ML per day in reach 4 will not be provided without agreement of potentially affected landholders.

2 Potential watering actions to Pyramid Creek and Loddon River reach 5 are contingent on the operation of the Box Creek fishway that allows fish movement to and from Kow Swamp.

Scenario planning

Due to low inflows to the Loddon system in 2015–16, the storage manager may not have enough water available to operate the system to deliver water held by entitlement holders in Tullaroop and Cairn Curran reservoirs in early 2016–17. If conditions remain dry, allocations will start at zero, carryover from 2015–16 may not be accessible and passing flows may not be delivered. Under dry conditions, this situation will continue until sufficient inflows enable releases to be made or alternate arrangements are negotiated with all users in the system.

We can access water held in the Goulburn system for delivery to the Loddon River downstream of the Waranga western channel at Loddon Weir, so limitations on passing flows and carryover in the Loddon system mostly affect the Loddon River upstream of the channel. However, Victorian Environmental Water Holder water in the Goulburn system could be unavailable from time to time due to capacity restrictions in the Waranga western channel and also when the irrigation season is closed (mid-May to mid-August).

Planning for 2016–17 has considered these operational problems and the impacts that consecutive dry years have had on the Loddon system. Under a drought scenario, low flows and a limited number of small freshes through reaches 1, 2 and 3 of the Loddon River will be provided from Loddon system storages (Cairn Curran and Tullaroop reservoirs) subject to sufficient water being available for use. The low flows will target the bottom end of reach 3b and the freshes will be delivered when required to improve water quality and help maintain riparian vegetation. Under a drought scenario there will be total reliance on water from the Goulburn system for flows to reach 4. If access to water from the Goulburn system is restricted (due to capacity restrictions in the Waranga western channel or outside the irrigation season), flows may be reduced which may affect our ability to maintain refuge habitat.

If dry to average conditions eventuate there will be increased access to water from the Loddon River storages, and the aim is to deliver flows commensurate with the seasonal conditions. Passing flow rules will largely meet low-flow requirements, but it may be necessary to supplement passing flows with additional releases to meet low-flow objectives from time to time. High flows and freshes to the Loddon River and Pyramid Creek will be delivered by coordinating water available in the Loddon, Goulburn and Murray systems.

More water will be available under the average to wet scenarios, allowing more regular deliveries that maximise environmental outcomes, focusing on increased platypus and fish movement and improving vegetation. In a very wet year most flows will happen naturally and only a small amount of environmental water will be used, placing the system in a good position for 2017–18.

Table 2 Potential environmental watering for the Loddon River system under a range of planning scenarios

Planning scenario

Drought

Dry

Average

Wet

Expected river conditions

  • Negligible contributions from unregulated reaches and tributaries of the Loddon River leading to lengthy cease-to-flow periods in the absence of environmental or consumptive water deliveries
  • Small contributions from unregulated reaches and tributaries of the Loddon River contributing to low flows
  • Unregulated flows will provide baseflows and multiple freshes, most likely in winter and spring
  • Multiple spills from Loddon system storages will provide extended-duration high flows and overbank flows at any time of year

Expected availability of environmental water1

  • 16,000 ML VEWH
  • 1,100 ML Commonwealth
  • 17,100 ML total
  • 16,000 to 18,000 ML VEWH
  • 1,100 to 1,600 ML Commonwealth
  • 17,100 to 19,600 ML total
  • 18,000 to 20,000 ML VEWH
  • 1,600 to 3,500 ML Commonwealth
  • 19,600 to 23,500 ML total
  • 20,000 ML VEWH
  • 3,500 ML Commonwealth
  • 23,500 ML total

Loddon River (reach 1) and Tullaroop Creek (reach 2)

Potential environmental watering

  • Year-round low flows2
  • 1–2 summer/autumn freshes2
  • Year-round low flows
  • 1–2 summer/autumn freshes
  • 1 winter/spring fresh
  • Up to 3 summer/autumn freshes
  • 1–2 winter/spring freshes
  • Up to 3 summer/autumn freshes
  • 2 winter/spring freshes

Loddon River (reaches 3a and 3b)

Potential environmental watering

  • Year-round low flows
  • Trigger-based freshes at any time of year to improve water quality and maintain riparian vegetation
  • Under dry-wet scenarios reach 3 objectives will be met by environmental water delivered from Loddon storages targeting reaches 1 and 2 and en route to reach 4, or by consumptive and system operating water

Loddon River (reach 4)

Potential environmental watering

  • Year-round low flows
  • 2–3 summer/autumn freshes
  • 1 winter/spring high flow
  • Year-round low flows
  • 2–3 summer/autumn freshes
  • 1 winter/spring high flow
  • Year-round low flows
  • 3 summer/autumn freshes
  • 1 winter/spring high flow
  • 1 autumn high flow
  • Year-round low flows
  • 3 summer/autumn freshes
  • 1 winter/spring high flow
  • 1 autumn high flow

Serpentine Creek

Potential environmental watering

  • Low flows provided by consumptive water
  • 1–2 summer/autumn freshes
  • 1–2 summer/autumn freshes
  • 1 winter/spring fresh

Loddon River, Tullaroop Creek and Serpentine Creek

Possible volume of environmental water required to achieve objectives

  • Up to 11,600 ML
  • 11,600 ML
  • 17,000 ML
  • 11,000–17,000 ML

Pyramid Creek and Loddon River (reach 5)

Potential environmental watering

  • 1 spring high flow
  • 1 spring high flow
  • 1 autumn high flow

Possible volume of environmental water required to achieve objectives

  • 12,000 ML
  • 24,000 ML

1 Does not include water available in the Goulburn and Murray systems that could be made available to support the achievement of environmental objectives in the Loddon system, subject to trading rules

2 Low flows and freshes in reaches 1 and 2 under the drought scenario will be provided by water en route to Loddon River reach 3.

Risk management

In preparing its seasonal watering proposal, North Central 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 North Central region communities are involved in decisions about the Loddon and Campaspe river systems, Murray river system including Gunbower Forest and some of the wetlands connected by the Wimmera-Mallee pipeline. This happens through formal advisory groups: Environmental Water Advisory Groups including river and wetland focused groups and the Gunbower Island Community Reference Group.

Who is engaged and how

Recreational users

Through formal advisory groups, recreational users provide local advice and raise opportunities for potential 'shared benefits' from environmental watering. Through Environmental Water Advisory Groups, recreational users are informed of environmental water deliveries and provide data that assists with reporting on the outcomes of environmental watering.

Goulburn-Murray Water engages with recreational user groups (such as Save Lake Eppalock and Lake Meran Users Group) that use water storages for recreation through planned consultations and meetings to discuss storage levels and potential impacts of environmental water releases from storages.

Environment groups

Through formal advisory groups, environment groups provide local knowledge, land management advice and advocate for the environment. They are also informed of environmental water deliveries and provide data that assists with reporting on the outcomes of environmental watering (including citizen science monitoring data such as providing bird counts).

Landholders/farmers

Through formal advisory groups, farmers and landholders (including those who own private wetlands that receive environmental water) provide local knowledge and land management advice regarding environmental watering.

They are also informed of environmental water deliveries and provide data that assists with reporting on the outcomes of environmental watering. Goulburn-Murray Water engages (and often) with consumptive entitlement holders (often irrigators) and landholders (often with river frontages).

Traditional Owners

Through the North Central Catchment Management Authority Indigenous Facilitator, Traditional Owners from the Barapa Barapa, Dja Dja Wurrung and Yorta Yorta Nations are given the opportunity to provide input to seasonal watering proposals. The Catchment Management Authority and the Barapa Barapa Nation have conducted a cultural values mapping project in Gunbower Forest which will eventually enable cultural values to be incorporated in Gunbower environmental water planning. The Barapa Barapa and Yorta Yorta Nations undertake monitoring of cultural values in Gunbower Forest.

There are Dja Dja Wurrung and Yorta Yorta representatives from the North Central region who are members of the Murray Lower Darling Rivers Indigenous Nations. The Victorian Environmental Water Holder, the Commonwealth Environmental Water Holder and the Murray Darling Basin Authority engage the Murray Lower Darling Rivers Indigenous Nations on strategic (often longer term) issues related to environmental watering.

Councils

Councils are invited to participate in formal advisory groups meetings. Goulburn-Murray Water  consults with the City of Greater Bendigo, Gannawarra Shire and Swan Hill Rural City Council regularly on water management, including on environmental water management.

General public

The North Central Catchment Management Authority communicates and engages with the general public through their website, media releases, newsletters, public notices, community forums, community events (such as tours of Gunbower Forest during environmental watering), social media and direct contact to interested parties by email distribution list.