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The construction and operation of Lake Eppalock has significantly altered downstream river flows and reversed the seasonal flows. The storage captures rainfall run-off and reduces natural winter and spring flows downstream, which is then released as increased flows over summer and autumn. Environmental water is held and released from Lake Eppalock, with some limited ability to regulate flows further downstream at the Campaspe Weir.

Higher flows in summer can mean less suitable habitat for juvenile fish. Delivering water to users downstream in the River Murray when they need it over summer is essential, and storage managers and the North Central Catchment Management Authority have been working cooperatively to do this in an environmentally sensitive manner. This cooperation results in deliveries to downstream users having as little negative effect on native plants and animals as possible.

Providing the target flows in all reaches below Lake Eppalock is important. Environmental watering usually targets reach 4 which will also achieve the desired flow objectives in reaches 2 and 3 (see below). Primary measurement points are at Barnadown (reach 2) and downstream of the Campaspe siphon (reach 4). In specific circumstances, water can be delivered to reach 4 from the Goulburn system via the Waranga western main channel.

System map

Campaspe 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 Campaspe River

Connected icon
Provide connection along the length of the Campaspe River and into the River Murray
Plant icon
Sustain adult river red gums and encourage the growth of new plants
Fish icon
Provide habitat to help protect and boost populations of native fish
Insect icon
Support a wide range of waterbugs to provide energy, break down dead organic matter and support the river’s food chain
Plant icon
Maintain and increase the cover of in-stream and riverside plants
Platypus icon
Support the resident platypus population by providing places to rest, breed and feed, as well as dispersal opportunities to the River Murray
Water icon
Control salinity and maintain healthy levels of oxygen in deep pools

Environmental values

The Campaspe River below Lake Eppalock provides important habitat for several fish species including the Murray cod, silver perch, golden perch, Murray–Darling rainbowfish and flat-headed gudgeon. Maintaining flows is important for migration and dispersal of young platypus and fish. Turtles and frogs are also present and there is a highly connected, intact river red gum canopy along the river banks that supports terrestrial species (such as the squirrel glider).

Social and economic values

The Campaspe River is an important source of water and a delivery mechanism for irrigation and town water. Popular recreational activities along the Campaspe River include camping, boating, kayaking, fishing, swimming, bush walking, picnicking and bird watching. These activities draw locals and tourists alike, providing economic benefit to towns along the river. The Campaspe River is culturally significant with Aboriginal cultural heritage sites such as shell deposits, scar trees, mounds and some artefacts recorded along the banks.

Conditions mid-2016

Rainfall was below-average in 2015–16 and the traditional storage inflow period of August–November recorded about 40 percent less than the long-term average. Consequently, streamflows into Eppalock for the year to the end of April 2015 were very low, equating to the driest three percent of years.

Environmental water was delivered in accordance with the dry conditions with low flows targeting minimum levels to support the native plants and animals that depend on the river. Where releases from storage for downstream users met the low-flow objective, environmental water was kept in the storage for later in the year.

Monitoring showed continuing improvement in native fish (with increased numbers of golden perch and Murray–Darling rainbowfish) while dwarf flathead gudgeon were recorded for the first time in 2015. To support native fish, environmental water was used to provide minimum flows during the year to maintain their habitat and allow movement of fish up and down the river, including to or from the River Murray. Small freshes (water pulses) in summer and autumn helped maintain water quality, trigger fish movement and support plants. One of the three freshes occurred following a summer storm in January, which resulted in rainfall run-off briefly increasing flows in the river. This natural event meant environmental water was not needed to deliver this fresh.

Surveys found that in-channel aquatic plant recovery following the millennium drought and subsequent flood is continuing. A range of species were identified, particularly in reaches 2 and 3 below the storage. Fringing plants have also continued to recover in these reaches. These improvements are not as great downstream between Rochester and Echuca (reach 4), possibly due to the heavier clay banks making it harder for new plants to establish, impacts such as stock access or a lack of seed from upstream.

Larger freshes delivered in winter helped platypus breed in the Campaspe. A number of landholders along the river shared their stories of sightings of the (often elusive) platypus.

Scope of environmental planning

Table 1 Potential environmental watering actions and objectives for the Campaspe River

Potential environmental watering

Environmental objectives

Summer/autumn low flows (10–50 ML/day in December–May)

  • Maintain aquatic vegetation
  • Maintain fish habitat and reinstate slack waters (areas with minimal water movement)
  • Limit the effect of cold water pollution from Lake Eppalock on fish
  • Maintain access to riffle habitat and water quality for waterbugs
  • Maintain permanent connectivity for water quality
  • Maintain permanent connectivity for platypus movement

Winter/spring high flows (up to 2 events at 1,000–1,800 ML/day for up to 7 days each in June–November)

  • Reduce encroachment of exotic and terrestrial vegetation
  • Enhance river red gum recruitment
  • Stimulate fish movement, allow movement to downstream reaches and provide spawning triggers
  • Flush and mix river pools for water quality
  • Flush organics from bank and benches to reduce the risk of blackwater events in summer
  • Mix and flush river pools for waterbugs
  • Inundate additional snags and flush sediment off biofilms (groups of microorganisms) for waterbugs
  • Support platypus habitat and breeding, including triggers for burrow selection

Winter/spring low flows (50–200 ML/day [or natural1], in June–November)

  • Provide longitudinal connectivity for fish
  • Maintain access to riffle habitat and water quality for waterbugs
  • Maintain permanent longitudinal connectivity of river for improved water quality
  • Facilitate platypus habitat and breeding opportunities

Summer/autumn freshes (up to 3 freshes of 50–200 ML/day for up to 3 days each in December–May)

  • Maintain riparian and in-channel recruitment vegetation
  • Increase extent of / maintain in-stream aquatic vegetation
  • Provide longitudinal connectivity for fish in periods of low flows
  • Maintain waterbug habitat and wash organic matter into the river to drive aquatic food webs
  • Respond to blackwater events as required

1 'Or natural' means that flow rates may be above or below the specified target rates depending on inflows and climatic conditions.

Scenario planning

Potential watering actions in 2016–17 range from those considered essential under extreme drought conditions through to those seeking to improve the ecological health of the river under wetter conditions, making it better-placed to withstand future stress events. The potential watering actions are similar across scenarios but the target magnitude and duration of the flows increase under wetter conditions, resulting in more environmental water being required as conditions become wetter.

Under continued dry conditions, it may not be possible for the storage manager to deliver water from Lake Eppalock, including environmental water. Without good inflows into storages from April to June 2016, not enough water will be available to enable the storage manager to operate the system to deliver water carried over into 2016–17. Under this scenario, allocations will start at zero and carryover from 2015–16 may not be able to be accessed until sufficient inflows occur or alternate arrangements are negotiated.

Protecting the environment under such conditions is a very high priority to prevent critical environmental loss. There is some possibility that water could be delivered to the lower part of the river (reach 4) from the Goulburn system via the Western Waranga main channel using environmental water or water from the Goulburn being delivered to meet demands in the Murray.

No critical carryover requirements have been identified for the Campaspe system into 2017–18: allocations available on 1 July 2017 from a very high-reliability component of the environmental entitlement will meet the highest-priority summer low flows in 2017–18. The best environmental outcomes are achieved by meeting 2016–17 demand rather than reserving water for the following year.

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

Planning scenario

Drought1

Drought

Dry

Below-average

Expected river conditions

  • No unregulated flows
  • No consumptive water deliveries except for minimal stock and domestic
  • No unregulated flows
  • Low consumptive water deliveries in reach 2 and low-to-no deliveries in reaches 3 and 4 in summer
  • Minimal unregulated flows in winter/spring
  • Low consumptive water deliveries in reach 2 and low deliveries in reaches 3 and 4 in summer
  • Some unregulated river flows particularly in winter/spring
  • Moderate summer consumptive water deliveries in reach 2 and low deliveries in reaches 3 and 4 in summer

Expected availability of environmental water

  • 0 ML VEWH
  • 0 ML CEWH
  • 0 ML Living Murray
  • 0 ML carryover
  • 0 ML withheld passing flows
  • 0 ML total
  • 1,656 ML VEWH
  • 0 ML CEWH
  • 0 ML Living Murray
  • 9,500 ML carryover
  • 2,000 ML withheld passing flows
  • 13,156 ML total
  • 3,900 ML VEWH
  • 980 ML CEWH
  • 20 ML Living Murray
  • 9,500 ML carryover
  • 2,000 withheld passing flows
  • 16,400 ML total
  • 19,500 ML VEWH
  • 6,000 ML CEWH
  • 100 ML Living Murray
  • 9,500 ML carryover
  • 2,000 ML withheld passing flows
  • 37,100 ML total

Potential environmental watering – tier 1 (high priorities)

  • Summer/autumn low flows (reach 4 only)
  • Emergency pulse flows to avoid critical loss of species/habitat (by preventing or responding to a low-dissolved-oxygen event and by maintaining pool habitat)
  • Summer/autumn low flows
  • Winter/spring high flow (1 event)
  • Winter/spring low flows
  • Summer/autumn fresh (1 event)
  • Summer/autumn low flows
  • Winter/spring high flow (1 event)
  • Winter/spring low flows
  • Summer/autumn freshes (3 events)
  • Low range summer/autumn low flows
  • Winter/spring high flows (2 events)
  • Winter/spring low flows
  • Summer/autumn freshes (3 events)

Potential environmental watering – tier 2 (additional priorities)

  • Winter/spring high flow (1 event)
  • Top-up winter/spring low flows
  • Summer/autumn freshes (2 additional events)
  • Top-up winter/spring low flows
  • Winter/spring high flow (1 additional event)
  • Top-up low flows year-round
  • Increased magnitude and duration of winter/spring high-flow events

Possible volume of environmental water required to achieve objectives2

  • 1,800 ML (tier 1)
  • 6,800 ML (tier 2)
  • 13,100 ML (tier 1)
  • 5,600 (tier 2)
  • 15,200 ML (tier 1)
  • 7,500 ML (tier 2)
  • 25,800 ML (tier 1)
  • 7,500 ML (tier 2)

1 Under this drought scenario it is assumed delivery of carryover and allocation is not available. Watering to protect plants and animals from critical loss is expected to be negotiated with relevant stakeholders.

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

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.