Skip to content
   
 

Water for the environment is supplied to Durt-Yowan (Latrobe River) from Blue Rock Reservoir on the Tanjil River. Blue Rock Reservoir also supplies water for urban supply and for electricity generators and a paper mill in the Latrobe Valley.

Options to deliver water for the environment to Durt-Yowan (Latrobe River) via the Tyers River may be investigated in 2021-22. These options include a physical transfer of water from Blue Rock Reservoir to Moondarra Reservoir via existing infrastructure operated by Gippsland Water or a temporary administrative transfer arrangement. Delivering water via the Tyers River would increase the proportion

of the Latrobe catchment that could receive water for the environment without compromising outcomes in the main target reaches of Durt-Yowan (Latrobe River). If adopted, these options are expected to benefit native in-stream and streamside vegetation and non-migratory fish within the Tyers River.

Durt-Yowan (Latrobe River) from Rosedale to Carran Carran (Thomson River) confluence (reach 5) is the priority reach for environmental watering because it contains endangered plant communities that have good potential for rehabilitation.

Traditional Owners
Storage manager
Environmental water holder

Environmental watering objectives in the Latrobe River

Fish icon
Maintain or increase native fish (migratory, resident and estuary) populations
Landscape icon
Maintain or increase in-stream geomorphic diversity
Platypus icon
Maintain or improve the extent of platypus and rakali (water rats) populations
Maintain the abundance of freshwater turtle populations
Plant icon
Improve the condition and increase extent and diversity of submerged, emergent and streamside native vegetation. Reduce the extent and density of invasive plants
Insect icon
Increase the abundance of all macro- and micro-invertebrates
Water icon
Avoid adverse water-quality conditions (such as high salinity) in the lower Latrobe River and estuary

System map

Latrobe River and Wetland 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 values

The upper reaches of Durt-Yowan (Latrobe River) flow through state forest and are relatively intact and ecologically healthy. It contains continuous stands of river red gums and intact streamside vegetation, and it supports native animals including barred galaxias, river blackfish, Gippsland spiny crayfish and nankeen night herons.

Durt-Yowan (Latrobe River) below Lake Narracan is regulated and highly degraded due to historic river management practices. Most large woody habitat has been removed from the river and many sections have been artificially straightened. These practices have caused significant erosion and widened the channel, which has in turn reduced the quality and quantity of habitat for aquatic plants and animals.

Endangered and vulnerable vegetation is found in all but the most modified sections of Durt-Yowan (Latrobe River). The banks along the lower reaches support stands of swamp scrub, characterised by swamp paperbark and tea tree. Mature river red gums grow adjacent to the lower Latrobe wetlands and provide nesting habitat for sea eagles and other birds of prey that hunt in the wetlands. Durt-Yowan (Latrobe River) supports several native estuarine and freshwater fish including black bream, Australian bass, Australian grayling and short- and long-finned eel. The river also provides habitat and supports feeding and breeding conditions for platypus, rakali (water rats) and freshwater turtles.

Durt-Yowan (Latrobe River) and its tributaries provide an essential source of freshwater to the Gippsland Lakes system, of which the lower Latrobe wetlands are an important component.

Recent conditions

Climatic conditions in the Latrobe catchment in 2020-21 were close to the long-term average, and some periods of above-average rainfall were observed. High levels of flow were sustained in Durt-Yowan (Latrobe River) for most of the year, and several minor floods occurred in winter and spring in the lower reach and estuary. Due to high inflows and little need for environmental flows in 2019-20, the full volume under the environmental entitlement was available at the start of the water year, and it was sustained for the rest of 2020-21 due to low demand.

Water for the environment was managed in line with an average climate scenario throughout 2020-21, and all planned watering actions were met or exceeded. Natural inflows provided several large flows that are needed to support key ecological and geomorphological processes and cannot be delivered through managed releases of water for the environment. This is the second year in a row where all deliverable flow components required for Durt-Yowan (Latrobe River) have been achieved, which has allowed some recovery in the system following dry years in 2017-18 and 2018-19.

Fish surveys conducted in Durt-Yowan (Latrobe River) in March 2021 detected many young-of-year tupong (indicating successful recent recruitment), 12 Australian bass and 25 percent fewer carp compared to 2015 survey results. Fish ecologists from the Arthur Rylah Institute for Environmental Research advised that maintaining minimum low-flow targets throughout 2021-22 will facilitate the upstream dispersal and increase the survival of new tupong recruits.

Traditional Owner cultural values and uses

The Gunaikurnai have had a continued connection to Gunaikurnai Country for thousands of years, including with the waterways in the Latrobe system. For the Gunaikurnai as traditional custodians, there are immense challenges to heal, protect and manage Country which has been drastically altered since colonisation. Gunaikurnai see all of Country as connected with no separation between landscapes, waterways, coasts and oceans and natural and cultural resources – the cultural landscape is interdependent.

Gunaikurnai Land and Waters Aboriginal Corporation (GLaWAC) is working with the West Gippsland CMA to determine how to express Gunaikurnai objectives for water in a way that contributes to seasonal watering proposals from the perspective of traditional custodians, with traditional knowledge.

GLaWAC is working in partnership with West Gippsland CMA to determine how cultural values and uses can be considered in planning for water for the environment. For the Latrobe system, this includes:

  • undertaking Aboriginal Waterways Assessments, to examine cultural values and uses, and incorporating the findings of assessments into the Latrobe Environmental Water Requirements Investigation
  • identifying primary objectives under the modified water regime
  • expressing preliminary outcomes: watering actions that recognise and promote:
    • healthy Country
    • the importance of the Latrobe river system to the Gunaikurnai songline of pelican and musk duck and their water quality and habitat requirements
    • waterways as meeting places
    • preliminary accommodation of the water quality and management requirements of species with cultural values and uses.

GLaWAC is sharing with the West Gippsland CMA its knowledge of plant and animal species of cultural significance in and around the waterways of the Latrobe Valley and the importance of specific watering decisions to support them.

Watering requirements to support cultural values and uses include:

  • timing environmental watering planned in partnership with GLaWAC to support a seasonal flow regime and wet and dry periods that embody healthy Country
  • maintaining freshwater supply to Latrobe estuary, Dowd Morass, Sale Common and Heart Morass and associated freshwater habitats. The lower Latrobe wetlands are an important resource for the Gunaikurnai
  • providing connectivity between reaches and onto floodplains to support dependent plants and animals with cultural values and uses of significance to the Gunaikurnai
  • maintaining water quality to support the health of native plants and animals with cultural values and uses of significance to the Gunaikurnai.

Social, recreational and economic values and uses

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

  • water-based recreation (such as fishing and water skiing)
  • riverside recreation and amenity (such as hunting)
  • socio-economic benefits (such as commercial fishing; diversion for domestic, irrigation and stock use; and power generation).

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 the following icon.

Kayak icons

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

West Gippsland CMA coordinates with the Lake Narracan Ski Club to plan the timing of releases of water for the environment so that they do not affect water levels in the lake during water skiing events held between January and March.

Scope of environmental watering

Table 1 describes the potential environmental watering actions in 2021-22, their expected watering effects (that is, the intended physical or biological effects of the watering action) and the longer-term environmental objectives they support. Each environmental objective relies on one or more potential environmental watering actions and their associated physical or biological effects.

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

Potential environmental watering action

Expected Watering Effects

Environmental objectives

Durt-Yowan (Latrobe River) (targeting reach 5)

Winter/spring low flow (620 ML/day during July to November 2021 and June 2022)

  • Wet benches to maintain habitat, support the growth of emergent macrophyte vegetation and limit encroachment of terrestrial vegetation
  • Maintain oxygen levels in pools and maintain sediment (sands and silts) in suspension to prevent pools filling and depositing on substrates, helping to maintain habitat for waterbugs, turtles, aquatic mammals and breeding substrate for river blackfish
  • Maintain longitudinal connectivity to allow movement/dispersal of native fish, turtles platypus and rakali (water rats)
Fish iconMountain iconsPlatypus iconTurtle iconPlant iconInsect iconWater drop icon

Summer/autumn low flow (250-380 ML/day during December to May)

  • Maintain an adequate depth in pool habitat to support native fish, turtles, platypus and rakali (water rats) and submerged vegetation
  • Limit encroachment by terrestrial vegetation and support the growth of emergent macrophyte vegetation
  • Mix pools to maintain oxygen levels suitable for aquatic animals
Fish iconPlatypus iconTurtle iconPlant iconInsect iconWater drop icon

Summer/autumn river freshes (three to six freshes of 920 ML/day for one to five days during December to May)

Kayak icons

Water-quality fresh (one-day duration):

  • freshen water quality in pools to support fish, waterbug and zooplankton communities
  • provide sufficient velocity to turn over and flush sediments (sands and silts) from pools and scour algae from hard surfaces

Fish and vegetation fresh (three to five days duration)
Objectives listed for the one-day fresh and additional objectives:

  • wet benches to support the growth of emergent macrophyte vegetation
  • clean fine sediment from stream bed substrates including river blackfish nesting habitats
  • provide longitudinal connectivity (including over benches for Australian grayling) for native fish, platypus and rakali (water rats)
Fish iconMountain iconsPlatypus iconPlant iconInsect iconWater drop icon

Summer/autumn estuary fresh(es) (one to three freshes of 2,200 ML/day at reach 6 for seven to 10 days during December to May)

Kayak icons

Objectives listed for the three-to-five-day river fresh and additional objectives for the Latrobe River estuary:

  • upper estuary: fully flush with freshwater to support submerged vegetation, provide adequate oxygen levels for aquatic animals, transport silt, wet benches and deliver freshwater to connected wetlands
  • mid-estuary: partially/fully flush the upper layer of the water column to improve water quality, support emergent macrophytes, provide freshwater habitat and associated food sources for freshwater fish and provide breeding opportunities for estuary fish
  • lower estuary: partially flush the upper layer of the water column; a flow of this magnitude will also provide opportunities to fill the lower Latrobe wetlands

Note: this event requires a contribution of 1,280 ML/day from Carran Carran (Thomson River) over the equivalent period to meet objectives

Fish iconMountain iconsPlatypus iconPlant iconWater drop icon

Engagement

Partners and stakeholders engaged by West Gippsland CMA in developing seasonal watering proposals for the Latrobe River, lower Latrobe wetlands, Thomson River and Macalister River systems and other key foundation documents that have directly informed the proposals

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

Partner and stakeholder engagement
  • Greening Australia
  • Latrobe Valley Field Naturalist Club Inc.
  • Native Fish Australia
  • Parks Victoria
  • Southern Rural Water
  • Gippsland Water
  • Department of Environment, Land, Water and Planning
  • East Gippsland CMA
  • Individual landholders
  • Port of Sale Heritage Cruises
  • Field & Game Australia
  • VRFish
  • Arthur Rylah Institute (Department of Environment, Land, Water and Planning)
  • Gunaikurnai Land and Waters Aboriginal Corporation

Page last updated: 22/01/21