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Birchs Creek is part of the broader Bullarook system which contains two small storages — Newlyn Reservoir and Hepburn Lagoon — which provide water for irrigation and urban supply. The storages fill and spill during winter or spring in years with average or above-average rainfall. The VEWH holds water for the environment in Newlyn Reservoir, but there is no water held in Hepburn Lagoon.

Birchs Creek receives tributary inflows from Rocky Lead, Langdons, Lawrence and Tourello creeks. Groundwater provides reliable baseflows to the downstream reaches of Birchs Creek in most years.

The VEWH is allocated 100 ML in Newlyn Reservoir on 1 December each year, provided that seasonal determinations in the Bullarook system are at least 20 percent. Any unused allocation from 1 December can be carried over until 30 November of the following water year, but if Newlyn Reservoir spills from 1 July to 30 November, the volume held in carryover is lost. Any water remaining on 30 November is forfeited. When seasonal determinations are below 20 percent, the VEWH does not receive an allocation, and the system’s resources are shared equitably to protect critical human and environmental needs.

Traditional Owners
Storage manager
Environmental water holder

Environmental watering objectives in Birchs Creek

Increase the population and diversity of small- and medium-bodied native fish including river blackfish, mountain galaxias, flat-headed gudgeon and Australian smelt
Platypus icon
Maintain the breeding population of platypus and increase the number of individuals to improve the population’s resilience to future droughts and floods

Provide surplus juvenile platypus that can disperse to Creswick and Tullaroop creeks
Plant icon
Maintain and improve the diversity and abundance of in-stream aquatic plants

Maintain a diverse variety of fringing and streamside native vegetation communities
Insect icon
Increase the population of waterbugs and the diversity of functional groups to drive productive and dynamic food webs
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Maintain water quality to support aquatic life and ecological processes

Environmental values

Birchs Creek supports threatened aquatic plants and its deep pools provide habitat for aquatic animals during dry periods. The creek contains native fish including regionally significant populations of river blackfish and mountain galaxias as well as flat-headed gudgeon and Australian smelt. Recent monitoring indicates that platypus are present throughout the entire creek.

The removal of willows along the creek in 2018 has improved in-stream vegetation and populations of small- bodied fish.

Traditional Owner cultural values and uses

In planning for environmental flows in Birchs Creek, Dja Dja Wurrung Clans Aboriginal Corporation and North Central CMA have identified the creek as a potential site for future projects.

The Dja Dja Wurrung Country Plan 2014-2034 describes their aspirations around the management of rivers and waterways and articulates Dja Dja Wurrung peoples’ support for the reinstatement of environmental flows as an overall objective for the management of water on Country.

The North Central CMA and Dja Dja Wurrung Clans Aboriginal Corporation continue to work towards increased engagement on planning and delivery of environmental watering activities, including identifying opportunities for Dja Dja Wurrung involvement.

Social, recreational and economic values and uses

In planning the potential watering actions in Table 5.7.5, North Central CMA considered how environmental flows could support values and uses including:

  • water-based recreation (such as fishing)
  • riverside recreation and amenity (such as cycling and walking, diversion for domestic and stock use and improving amenity at key community spaces like Anderson’s Mill).

Recent conditions

Although July rainfall was well-below average, near-average rainfall was observed during late winter to early summer, and January rainfall was well above average. Water for the environment allocated in December 2019 was carried into the 2020-21 water year, but it was lost due to regular spills at Newlyn Reservoir throughout winter and spring 2020. The full 100 ML allocation was again received on 1 December 2020.

Regular storage spills and contributions from groundwater led to all of the winter and spring flow requirements for Birchs Creek being met or exceeded. Low flow and freshes over summer and autumn were met with a combination of natural flow from summer storms and groundwater baseflow, as well as consumptive releases in reaches 1 and 2. No additional freshes were required in Birchs Creek in 2020-21, so the allocation from December 2020 will be carried over to support watering actions in 2021-22.

Scope of environmental watering

Table 1 Potential environmental watering actions and objectives for Birchs Creek

Potential environmental watering

Expected watering effects

Environmental objectives

Winter/spring fresh (one fresh of 27 ML/day for three days during June to November)

  • Maintain and support the growth and germination of streamside vegetation by increasing soil moisture and depositing sediment on the bank and benches
  • Scour old biofilms and organic matter that has accumulated in the channel, and cycle nutrients throughout the creek
  • Wet benches and banks, to increase habitat and refuge for small fish
  • Improve water quality by freshening refuge pools and provide connectivity between pools for fish and platypus movement
Fish iconPlant iconWater drop iconPlatypus iconInsect icon

Summer/autumn freshes (three freshes of 10 ML/ day for three days during December to May)

  • Increase the water depth, to maintain and support seed germination and the growth of in-stream aquatic vegetation
  • Expand riffle/run areas to provide waterbug habitat
  • Top up pools to refresh water quality (particularly oxygen levels) and enhance connectivity between pools, for fish and platypus movement
Fish iconPlant iconWater drop iconPlatypus iconInsect icon

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
  • Goulburn- Murray Water
  • Department of Environment, Land, Water and Planning (land manager)
  • Individual landholders
  • Central Highlands Water

Page last updated: 22/01/21