VEWH - Latrobe River

The Latrobe River originates on the Baw Baw Plateau and passes through relatively flat to undulating plains cleared for agriculture, before flowing into Lake Wellington (the westernmost point of the Gippsland Lakes). Notable tributaries include the Tanjil River, Narracan Creek, Morwell River, Tyers River, Traralgon Creek and the Thomson River.

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

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

Environmental watering objectives in the Latrobe River

Maintain or increase native fish (migratory, resident and estuary) populations

Maintain or increase in-stream geomorphic diversity

Improve the condition and increase extent and diversity of submerged, emergent and streamside native vegetation Reduce the extent and density of invasive plants

Increase the abundance of all macro- and micro-invertebrates

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 Latrobe River flows through state forest and is 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.

The 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 are found in all but the most modified sections of the 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. The Latrobe River supports several native estuarine and freshwater fish including black bream, Australian bass, Australian grayling and short- and long-finned eel.

The 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

The Latrobe system experienced average to above-average rainfall throughout 2019–20, despite drier-than-average conditions occurring elsewhere in west Gippsland. By summer, environmental water allocations reached 100 percent of the entitlement volume.

Local rainfall and inflows from unregulated tributaries provided flow conditions that met all the watering actions that were planned for the Latrobe River from July 2019 until February 2020. High rainfall caused bankfull flows in winter and minor flooding in some reaches of the Latrobe River in late spring 2019, which provided ecologically important flow events that cannot be delivered through managed environmental flows. Water for the environment was used to partly deliver two freshes in mid-autumn 2020. Heavy rainfall occurred during these events, which reduced the amount of environmental water that needed to be released. The autumn freshes were timed to coincide with environmental flows in the Thomson and Macalister rivers to optimise outcomes for native fish (especially Australian grayling migration and spawning) and outcomes for the Latrobe estuary.

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 River 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.

For the Latrobe River system this has included:

Aboriginal Waterway Assessments to examine cultural values and uses
identification of primary objectives under the modified water regime
expression of preliminary outcomes: watering actions that recognise and promote:
- Healthy Country
- the importance of the Latrobe River system to the Gunaikurnai songline of Boran (pelican) and Tuk (musk duck) and their respective water quality and habitat requirements
- waterways as meeting places
- preliminary accommodation of water quality and management requirements of species with cultural values and uses.

GLaWAC shared with the West Gippsland CMA 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 of 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 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 water-skiing and fishing)
riverside recreation and amenity (such as hunting)
socio-economic benefits (such as commercial fishing, diverters for irrigation and farming, urban water supplies 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 an icon.

Watering planned to support water sports activities (e.g. canoeing, kayaking, rowing, swimming, water skiing)

West Gippsland CMA communicates with Lake Narracan Ski Club so environmental water releases can be timed to not affect the water levels in the lake during water skiing events, which typically take place between January and March.

Scope of environmental watering

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

Potential environmental watering action	Functional watering objectives	Environmental objectives
Summer/autumn low flow(250 ML/day or natural during December to May)	Maintain an adequate depth in pool habitat to support aquatic animals and submerged vegetation Limit encroachment by terrestrial vegetation and support the growth of emergent macrophyte vegetation Maintain oxygen levels in pools Maintain sediments in suspension to prevent pools filling
Summer/autumn river fresh (one to four freshes of 920 ML/day for one to five days during December to May)	Wet benches to maintain habitat and support the growth of emergent macrophyte vegetation Freshen water quality to support waterbug and zooplankton communities Flush sediment (sands and silts) from pools and mix water in pools, helping to provide spawning conditions for Australian rayling and breeding substrate for river blackfish Provide longitudinal connectivity for aquatic animals
Summer/autumn estuary fresh (one to three freshes of 2,200 ML/day at reach 6 for seven to 10 days during December to May)	Objectives listed for the summer/autumn river fresh and additional objectives for the Latrobe River estuary: upper estuary: fully flush with freshwater to support submerged vegetation, provide suitable conditions including 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 to the lower Latrobe wetlands Note: This event requires contributions of at least 1,280 ML/day from the Thomson River at Bundalaguah over the equivalent period to meet objectives
Summer/autumn estuary fresh (one to three freshes of 2,200 ML/day at reach 6 for seven to 10 days during December to May)	Latrobe River objectives: wet banks and higher benches to improve the condition of streamside vegetation provide a variety of wetted areas for emergent macrophytes maintain channel capacity and bench habitat Additional objectives for the Latrobe River estuary: upper estuary: fully flush with freshwater to support submerged vegetation, increase 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 to the lower Latrobe wetlands Note: Delivering the target flow event in the estuary will require contributions of 1,000–2,200 ML/day from the Thomson River at Bundalaguah over the equivalent period to meet objectives
Winter/spring low flow (620 ML/day during June to November)	Wet benches to maintain habitat and support the growth of emergent macrophyte 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 and breeding substrate for river blackfish Longitudinal connectivity to allow movement/dispersal of aquatic animals

¹ This fresh may involve inundating private land if delivered at higher magnitude, and it will be subject to obtaining landholder agreement. The magnitude of delivery depends on the relative contribution possible from the Thomson system.

Engagement

Table 2 shows the partners with which West Gippsland CMA engaged when preparing the Latrobe system seasonal watering proposal.

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 longer term integrated catchment and waterway management objectives. For further details, refer to the West Gippsland Regional Catchment Strategy and West Gippsland Waterway Strategy.

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

Partner and stakeholder engagement
Greening Australia Latrobe Valley Field Naturalists Native Fish Australia Parks Victoria Gippsland Water Department of Land, Environment, Water and Planning (Latrobe Valley Regional Water Study) Department of Land, Environment, Water and Planning (Waterways and Catchments) East Gippsland CMA Individual landholders Port of Sale Heritage River Cruises VRFish Gunaikurnai Land and Waters Aboriginal Corporation

Partner and stakeholder engagement

Greening Australia
Latrobe Valley Field Naturalists
Native Fish Australia
Parks Victoria
Gippsland Water
Department of Land, Environment, Water and Planning (Latrobe Valley Regional Water Study)
Department of Land, Environment, Water and Planning (Waterways and Catchments)
East Gippsland CMA
Individual landholders
Port of Sale Heritage River Cruises
VRFish
Gunaikurnai Land and Waters Aboriginal Corporation

Page last updated: 22/01/21