VEWH - Glenelg system

Moora Moora Reservoir and Rocklands Reservoir are Wimmera-Mallee System Headworks water storages in the Glenelg River system that contribute to the supply of water to towns and properties across the Wimmera, Mallee, Glenelg, Loddon and Avoca catchments. Water for the environment is actively managed in the Glenelg River below Rocklands Reservoir. Passing- flow rules are in place for the Glenelg River and upper Wannon River.

The priority reaches of the Glenelg River that can be targeted by environmental flow releases are Rocklands Reservoir to

5-Mile Outlet (reach 1a), 5-Mile Outlet to the confluence with the Chetwynd River (reach 1b), Chetwynd River to the Wannon River (reach 2) and Wannon River to the tidal extent just below the confluence with Crawford River (reach 3). Water for the environment in the Glenelg system is released from Rocklands Reservoir for reach 1a via the reservoir wall outlet and for reaches 1b, 2 and 3 via the 5-Mile and 12-Mile outlets.

The Glenelg River estuary benefits from releases of water for the environment to upstream reaches, but releases do not currently target the estuary. Glenelg Hopkins CMA is investigating the influence of water for the environment on the Glenelg River estuary, which is listed as a heritage river reach and a site of international significance under the Ramsar Convention.

Proportion of water entitlements in the Glenelg system held by private users, water corporations and environmental water holders on 30 June 2020

System map

Environmental watering objectives in the Glenelg system

Protect, maintain and where possible enhance populations of endemic fish, including threatened and diadromous species

Maintain deep pool habitats and connectivity along the river

Maintain the platypus population

Maintain healthy and diverse mosaics of water-dependent vegetation (such as river red gums and Wimmera River bottlebrush)

Maintain a wide range and large number of waterbugs to break down organic matter and support the river’s food chain

Maintain water quality for native fish, waterbugs, aquatic vegetation and other water-dependent animals

Environmental values

The Glenelg River starts in the Grampians (Gariwerd) National Park and flows to the sea through the Lower Glenelg National Park. The lower reaches of the Glenelg River are part of a landscape recognised as one of Australia’s 15 national biodiversity hotspots, and the Glenelg Estuary and Discovery Bay site is Australia’s most recent listing under the Ramsar Convention.

The Glenelg River supports a range of rare and unique aquatic life, including the endangered Glenelg freshwater mussel, Glenelg spiny crayfish and a newly described species of river blackfish. It is also home to platypus and populations of native fish, including estuary perch, kooyang (short-finned eel), tupong and three species of pygmy perch, including the threatened variegated pygmy perch and Yarra pygmy perch. Some of these fish species migrate long distances to and from the Glenelg River estuary to complete their life cycles.

Frasers Swamp is another important feature of the upper Glenelg system and is home to a healthy growling grass frog population.

The Glenelg River supports a variety of streamside vegetation communities and species, including the endangered Wimmera bottlebrush. Streamside and floodplain vegetation is comprised of river red gum woodlands with paperbark, bottlebrush and tea tree understorey.

Traditional Owner cultural values and uses

The Glenelg River, known as Bochara in Dhauwurd Wurrung, Pawur in Bunganditj and Bogara in Wergaia-Jadawadjali languages, is a significant feature in the cultural landscape of south-western Victoria. The river features in the region’s creation stories. Bochara-Bogara-Pawur continues to be an important place for Traditional Owners, who have inhabited the area for thousands of years, using the rich resources available along the river and the associated habitats.

In planning for environmental flows in the Glenelg River, the Gunditj Mirring Traditional Owners Aboriginal Corporation, Barengi Gadjin Land Council, Burrandies Aboriginal Corporation and Glenelg Hopkins CMA have considered:

supporting the health of cultural heritage sites (such as scar trees, ring trees, stone structures, middens and rock paintings) and the health of native plants, which are sources of traditional foods and medicines
that improving the health and abundance of totem species and their habitat by delivering water for the environment also benefits Traditional Owners’ spiritual wellbeing
supporting contemporary cultural events (such as the Johnny Mullagh Cup).

Aboriginal Peoples across the Glenelg catchment have retained a strong identity and connection to the traditional lands for which they have custodial rights and responsibilities. Traditional Owners’ values in the Bochara-Bogara-Pawur system align strongly with environmental values. Traditional Owners’ values are holistic and interrelated: they are bound up with the health of the river system overall and the Country of which the river is part. Traditional Owners’ wellbeing is connected to the health of the river and of Country.

Gunditjmara Traditional Owners have identified that it is a priority to spend time on the river and increase cultural practices and connection to Country. They have highlighted the importance of increasing ceremonial and on-Country gatherings along the river, including at Casterton and Nelson.

The Glenelg River Yarns website (glenelgriveryarns.com.au) was launched in late 2021 as part of the Glenelg River Cultural Flows project. The website shares cultural values and stories on a virtual tour and welcomes all visitors to Country.

Figure 4.2.2 Glenelg River Environmental Flow Seasonal Calendar

Figure 4.2.2 Glenelg River Environmental Flow Seasonal Calendar

Figure 4.2.2 describes the six seasons of Gunditjmara Country, and it was produced by the Gunditj Mirring Traditional Owners Aboriginal Corporation. The northern part of the river upstream of the Harrow area is in Jadawadjali Country, and the south- western part of the system is in Boandik Country. The calendar describes the six seasons alongside flow components for reach 1b of the Glenelg River — from 5-Mile Outlet to Chetwynd River — and aligns them with corresponding watering effects and objectives. The calendar reflects the seasonal flow conditions that all Traditional Owner groups recognise.

The value of the calendar is in its clear visual depiction of Traditional Owners’ knowledge, developed over many generations, of how varying flows correspond to seasonal conditions and broader environmental patterns. In recognition of this knowledge, the Gunditjmara seasons have been incorporated into Table 4.2.1 as a complementary description of the timing of potential watering actions. The six seasons will eventually be embedded in environmental flow recommendations and scenario planning in future years.

Increasing the involvement of Traditional Owners in the planning and management of environmental flows and ultimately providing opportunities to progress towards self-determination within the environmental watering program is a core commitment of the VEWH and its agency partners. This is reinforced by a range of legislative and policy commitments, including the Water Act 1989, the Victorian Aboriginal Affairs Framework, the 2016 Water for Victoria and in some cases, agreements under the Traditional Owner Settlement Act 2010.

Where Traditional Owners are more deeply involved in the planning and/or delivery of environmental flows for a particular site, their contribution is acknowledged in Table 4.2.1 with an icon. The use of this icon is not intended to indicate that these activities are meeting all the needs of Traditional Owners but is incorporated in the spirit of valuing their contribution and indicating progress towards deeper involvement.

Watering planned and/or delivered in partnership with Traditional Owners to support Aboriginal cultural values and uses

The timing of the summer/autumn fresh is planned to support the annual Johnny Mullagh Cup cricket match between the Gunditj Mirring and Barengi Gadjin Traditional Owners. The fresh will improve water quality in swimming holes and improve amenity for Traditional Owners attending the cricket match, which is an important cultural event on the river.

Social, recreational and economic values and uses

In planning the potential watering actions in Table 4.2.1, Glenelg Hopkins CMA considered how environmental flows could support values and uses, including:

water-based recreation (such as canoeing and fishing)
community events and tourism (such as the Johnny Mullagh Cup and visitation)
socioeconomic benefits (such as for diverters for stock needs and domestic use: water levels and water quality can rely on the delivery of water for the environment, particularly in summer).

If the timing or management of planned environmental flows may be modified to align with a community benefit, this is acknowledged in Table 4.2.1 with the following icons.

	Watering planned to support angling activities
	Watering planned to support water sports activities (e.g. canoeing)
	Watering planned to support peaks in visitation (e.g. camping or other public activities on long weekends or school holidays)

Environmental flow releases support the spawning and recruitment of popular angling species like estuary perch and bream. Local anglers continue to report increased fish activity associated with the delivery of freshes, improving fishing opportunities in the river. Releases support numerous fishing competitions, including those of the Balmoral, Casterton and Dartmoor angling clubs.

The planning of the summer fresh improves accessibility, water quality and amenity for canoeists planning trips on the Glenelg River over the summer holiday period.

Summer and spring freshes improve conditions at popular riverside campgrounds in the upper reaches of the Glenelg River, including Fulham Reserve near Balmoral and the Johnny Mullagh Reserve at Harrow.

Recent conditions

Rainfall in the Glenelg catchment in 2021-22 was close to the long-term average, and consistent rain events over spring and summer contributed to significant tributary inflows below Rocklands Reservoir. However, rainfall in the catchments of the Wimmera-Mallee System Headworks storages was below the long-term average. Low storage levels at the beginning of the season coupled with limited inflows to storages meant allocations to the Wimmera and Glenelg Rivers Environmental Entitlement 2010 only reached 59 percent by early May 2022. Summer rain events provided natural freshes in the system, contributing to the maintenance of river connectivity throughout the season. Large natural flows during August peaked at 1,598 ML per day in reach 1b and 1,859 ML per day in reach 2, providing natural connections between the river and some low- lying floodplain areas.

The Glenelg system was managed under a dry climate scenario through 2021-22, with an emphasis on conserving water for carryover. Most planned watering actions were at least partially achieved through a combination of natural flows, managed passing flows and water for the environment, although results varied between reaches. Water for the environment was used to supplement summer/autumn low flows and summer/autumn freshes, particularly in reach 1b and reach 2. Flow targets were largely met in reach 1b and reach 3, which had significant inflows from local tributaries and received the most water for the environment. Most flow targets were also met in reach 2, although the natural freshes in summer and autumn were relatively small.

Small releases from Rocklands Reservoir wall outlet have little effect on downstream reaches. To conserve water in dry conditions, most water for the environment is released from Five Mile Outlet to optimise outcomes in reach 1b and reach 2. In 2020-21, water for the environment was used to supplement the natural baseflow in reach 1a to help maintain a continuous flow between Rocklands Reservoir and the estuary throughout the year. The preferred flow targets for reach 1a were generally not met due to Rocklands Reservoir affecting the natural inflow through this reach. The flow through reach 1a likely prevented significant environmental harm, but larger flows will be needed in coming years to improve environmental outcomes in that part of the river. Good flow during 2021-22 has allowed the maintenance of connection from Rocklands Reservoir to the estuary at Nelson. This flow has supported a diverse range of healthy habitats and provided beneficial dispersal opportunities required by native plants and animals throughout the Glenelg system.

Scope of environmental watering

Table 1 Potential environmental watering actions, expected watering effects and associated environmental objectives for the Glenelg River

Potential environmental watering action	Expected watering effects	Environmental objectives
Winter/spring low flow in reach 1a (60 ML/day or natural during June to November)	Maintain water quality for fish and waterbugs Wet aquatic vegetation to maintain its condition and prevent encroachment by terrestrial species Maintain shallow-water habitat for fish, waterbugs and platypus
Winter/spring low flow in reach 1b (100 ML/day or natural during June to November/Big Wet to Fattening Up*)
Winter/spring low flow in reach 2 (160 ML/day or natural during June to November)
Winter/spring low flow in reach 3 (400 ML/day or natural during June to November)	Wet benches to increase habitat and allow widespread fish passage
Winter/spring fresh(es) in reach 1b (one to five freshes of 250 ML/ day for one to five days during June to November/Big Wet to Fattening Up*)	Wet benches to improve the condition of emergent vegetation and vegetation on the riverbanks to support recruitment and growth and maintain habitat diversity Provide adequate depth for fish passage and cue fish movement Encourage female platypus to select a nesting burrow higher up the bank to reduce the risk of greater flow later in the year flooding the burrow when juveniles are present Scour sand from pools to improve the quality of fish habitat
Winter/spring fresh(es) in reach 2 (one to five freshes of 300 ML/ day for one to five days during June to November)
Summer/autumn low flow in reach 1a (10 ML/day or natural during December to May)	Protect against rapid water-quality decline over the low-flow period Maintain edge habitats, pools and shallow-water habitat for fish, waterbugs and platypus Maintain a near-permanent wetted stream channel to promote the growth of in-stream vegetation and prevent encroachment by terrestrial plants
Summer/autumn low flow in reach 1b (15 ML/day or natural during December to May/Big Dry to Early Wet*)
Summer/autumn low flow in reach 2 (25 ML/day or natural during December to May)
Summer/autumn low flow in reach 3 (80 ML/day or natural during December to May)
Summer/autumn freshes in reach 1a (one to two freshes of 60 ML/day for two to three days during December to May)	Flush fine silt from the stream bed and hard substrate to improve the quality of the fish and waterbug habitat Wet emergent vegetation on the lower banks to improve its condition and prevent the encroachment of terrestrial species Flush pools to improve water quality and lower temperatures Provide sufficient flow to allow native fish and platypus to access habitat
Summer/autumn fresh(es) in reach 1b (one to two freshes of 100 ML/day for two to three days during December to May/Big Dry to Early Wet*)
Summer/autumn fresh(es) in reach 2 (one to two freshes of 150 ML/day for two to three days during December to May)
Summer/autumn fresh(es) in reach 3 (one to two freshes of 150 ML/day for three days each or natural during December to May)

^* See Figure 4.2.2: Glenelg River Environmental Flow Seasonal Calendar.

Scenario planning

Table 4.2.2 outlines potential environmental watering and expected water use under a range of planning scenarios.

The strategy for delivering environmental flows in the Glenelg River has been developed to protect the most significant environmental values within the system and to make the best use of available water. As a result, there are some notable differences in watering priorities between reaches under each climate scenario.

Under a drought or very dry climate scenario, there will be limited water for the environment, and because the catchment will be relatively dry, deliveries will only influence conditions in the reaches close to the release point. Under these scenarios, most of the available water for the environment will be used to deliver summer/autumn low flows from Five Mile Outlet at the top of reach 1b to maintain a continuous flow between that point and Casterton, where the flow can be sustained by tributary inflows. Under a drought scenario, a low flow in reach 2 will likely be delivered at less than the recommended magnitude to conserve the available resource, but it should be possible to deliver the recommended low flow under a very dry scenario. These continuous flows will be essential to maintaining native fish and platypus populations that have recovered since the Millennium Drought.

Small volumes of water for the environment will also be used under drought or very dry conditions to deliver summer/autumn freshes to reach 1a. These flows will aim to top up key refuge pools to help small-bodied fish, macroinvertebrates and some aquatic vegetation persist in reach 1a, but they will not maintain a continuous flow through that reach. Natural inflows and cooler temperatures are likely to maintain a connecting flow through most of the system during winter and spring, even under a drought or very dry scenario, so no environmental flows are planned for those seasons.

If more water is available under dry, average and wet climate scenarios, it will be used to deliver summer/autumn freshes to as many reaches as possible and to provide a continuous flow through reach 1a to grow populations of native plants and animals. These freshes would wet streamside vegetation and provide more opportunities for fish and platypus to move through the system and increase their access to food and alternative habitats. Natural inflows under average and wet climate scenarios would deliver larger baseflows, and water for the environment may be delivered on top of these to achieve recommended low- flow magnitudes in some seasons to boost ecosystem productivity.

If more water becomes available, the next priorities under all scenarios will be to deliver winter/spring low flow and winter/ spring freshes in all reaches. These flows facilitate the migration and spawning of native fish from the upper reaches down to the estuary. Providing periods of additional or increased flow during winter/spring is likely to also support the re-establishment of small-bodied native fish populations in the upper Glenelg River and Frasers Swamp, located in reach 1.

Reserving water for carryover into the 2023-24 water year is a priority under all scenarios for the Wimmera and Glenelg Rivers Environmental Entitlement 2010. Carryover is vital to ensure there is sufficient water to deliver the highest-priority flows during summer and autumn 2023-24 if there are low allocations during the year. A range of scenarios has been discussed for carryover targets under the entitlement. The VEWH will consult with the Wimmera and Glenelg Hopkins CMAs during the season and set a final target when there is sufficient information to do so. The target carryover volume for 30 June 2023 will be based on use during 2022-23, environmental conditions and seasonal outlooks for 2023-24.

Planning scenario table

Table 4.2.2 Potential environmental watering for the Glenelg system under a range of planning scenarios

Planning scenario	Drought	Very dry	Dry	Average	Wet
Expected river conditions	No passing flow and low volumes of compensation and natural flow	Low volumes of passing, compensation and natural flow	Some passing, compensation and natural flow	Some passing, compensation and significant natural flow, particularly in winter/spring	Passing, compensation and natural flow meet some watering requirements in winter/spring
Predicted supply of water for the environment¹	25,400 ML	32,300 ML	43,500 ML	54,600 ML	64,800 ML
Glenelg River (targeting reach 1a)
Potential environmental watering – tier 1 (high priorities)	Tier 1a (can be achieved with predicted supply)
	Summer/ autumn freshes (two freshes)	Summer/ autumn fresh (one fresh)	Summer/ autumn low flow Summer/ autumn freshes (two freshes)	Winter/spring low flow Summer/ autumn low flow Summer/ autumn freshes (two freshes)	Winter/spring low flow Summer/ autumn low flow Summer/ autumn freshes (two freshes)
	Tier 1b (supply deficit)
	Winter/spring low flow Summer/ autumn low flow	Winter/spring low flow Summer/ autumn low flow Summer/ autumn fresh (one additional fresh)	Winter/spring low flow	N/A
Glenelg River (targeting reach 1b)
Potential environmental watering – tier 1 (high priorities)	Tier 1a (can be achieved with predicted supply)
	Summer/ autumn low flow	Summer/ autumn low flow	Summer/ autumn low flow Summer/ autumn freshes (two freshes)	Summer/ autumn low flow Summer/ autumn freshes (two freshes)	Summer/ autumn low flow Summer/ autumn freshes (two freshes)
	Tier 1b (supply deficit)
	Winter/spring low flow Winter/spring fresh (one fresh) Summer/ autumn freshes (two freshes) Winter/spring low flow	Winter/spring fresh (one fresh) Summer/ autumn fresh (one fresh)	Winter/spring low flow Winter/spring freshes (two freshes)	Winter/spring low flow Winter/spring freshes (three freshes)	Winter/spring low flow Winter/spring freshes (five freshes)
Glenelg River (targeting reach 2)
Potential environmental watering – tier 1 (high priorities)	Tier 1a (can be achieved with predicted supply)
	Summer/ autumn low flow (partial delivery)	Summer/ autumn low flow	Summer/ autumn low flow Summer/ autumn freshes (two freshes)	Summer/ autumn low flow Summer/ autumn freshes (two freshes)	Summer/ autumn low flow Summer/ autumn freshes (two freshes)
	Tier 1b (supply deficit)
	Winter/spring low flow Winter/spring fresh (one fresh) Summer/ autumn low flow (full delivery) Summer/ autumn freshes (two freshes)	Winter/spring low flow Winter/spring fresh (one fresh) Summer/ autumn freshes (two freshes)	Winter/spring low flow Winter/spring freshes (two freshes)	Winter/spring low flow Winter/spring freshes (three freshes)	Winter/spring low flow Winter/spring freshes (five freshes)
Glenelg River (targeting reach 3)
Potential environmental watering – tier 1 (high priorities)	Tier 1a (can be achieved with predicted supply)
	N/A			Summer/ autumn freshes (two freshes)	Summer/ autumn low flow Summer/ autumn freshes (two freshes)
	Tier 1b (supply deficit)
	Winter/spring low flow Summer/ autumn low flow Summer/ autumn freshes (two freshes)	Winter/spring low flow Summer/ autumn low flow Summer/ autumn fresh (one fresh)	Winter/spring low flow Summer/ autumn low flow Summer/ autumn freshes (two freshes)	Winter/spring low flow Summer/ autumn low flow	Winter/spring low flow
Possible volume of water for the environment required to achieve objectives	6,962 ML (tier 1a) 47,430 ML (tier 1b)	7,962 ML (tier 1a) 44,528 ML (tier 1b)	11,440 ML (tier 1a) 38,979 ML (tier 1b)	16,460 ML (tier 1a) 38,183 ML (tier 1b)	21,327 ML (tier 1a) 25,778 ML (tier 1b)
Priority carryover requirements1	14,000 ML	19,000 ML	23,000 ML	28,000 ML	32,000 ML

¹ Volume applies to the shared Wimmera and Glenelg Rivers Environmental Entitlement 2010.

Engagement

Table 2 shows the partners, stakeholder organisations and individuals with which Glenelg Hopkins CMA engaged when preparing the Glenelg 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 longerterm integrated catchment and waterway management objectives. For further details, refer to the Glenelg Hopkins Regional Catchment Management Strategy and Glenelg Hopkins Waterway Strategy for further details.

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

Partner and stakeholder engagement
Friends of the Glenelg River Glenelg River User Group Department of Environment, Land, Water and Planning Grampians Wimmera Mallee Water Parks Victoria Victorian Fisheries Authority Wimmera Catchment Management Authority Individual landholders Balmoral Bush Nursing Centre Balmoral Post Office Glenelg River Boat Cruises Grampians Resort Nelson Boat and Canoe Hire Paestan Canoe Hire Vickery Brothers (sand extraction) Balmoral Angling Club Casterton Angling Society Dartmoor Angling Club Individual anglers South-west Fishing Reports VRFish Gunditj Mirring Traditional Owner Corporation Barengi Gadjin Land Council Burrandies Aboriginal Corporation

Partner and stakeholder engagement

Friends of the Glenelg River
Glenelg River User Group
Department of Environment, Land, Water and Planning
Grampians Wimmera Mallee Water
Parks Victoria
Victorian Fisheries Authority
Wimmera Catchment Management Authority
Individual landholders
Balmoral Bush Nursing Centre
Balmoral Post Office
Glenelg River Boat Cruises
Grampians Resort
Nelson Boat and Canoe Hire
Paestan Canoe Hire
Vickery Brothers (sand extraction)
Balmoral Angling Club
Casterton Angling Society
Dartmoor Angling Club
Individual anglers
South-west Fishing Reports
VRFish
Gunditj Mirring Traditional Owner Corporation
Barengi Gadjin Land Council
Burrandies Aboriginal Corporation

Page last updated: 01/12/22