Avon Valley Water Security Project

The project aims to supply:

Sustainably supply 6 GL/year from the Macalister Irrigation District into a greenfield area that currently relies on an unreliable water supply from the Avon River for irrigation.  

• Improve natural flows in the Avon River by replacing the irrigation supply from the river with a supply from the Macalister Irrigation District.  
• Reconfigure the Nuntin Supply area to complete its automation and realise water savings that can be shared with Gunaikurnai Land and Waters Aboriginal Corporation, and the environment.  
• Benefit existing customer service levels in the Nuntin region through the addition of balancing storage.
• Ensure existing Macalister Irrigation District customers receive the same or improved service levels.
• The detailed business case for the Avon Valley Water Security Project will implement Action 7-2 and will deliver against Policy 8-9: (Return water to the Carran Carran), Policy 8-11: (Return water to the Macalister River) and Policy 8.14 (Improve Avon Flows).
   

Since 2017, Southern Rural Water has completed numerous investigations to assess opportunities on the Latrobe and Avon Rivers. These packages of work undertook broad-scale water resource availability and land capability assessments to determine areas where suitable land coincided with potentially available water.

Following this, pre-feasibility work was completed to prepare preliminary concept designs of new water delivery systems, water demand assessments, desktop environmental and cultural heritage assessments, economic and cost-benefit analysis to further prioritise areas.

To date, we have undertaken crucial technical studies that allow us to better understand the available water resources today and tomorrow under a range of future climate scenarios.

These studies also help inform a functional design for a pipeline network and balancing storage, water savings and losses, channel operation and service, environmental and cultural heritage considerations, project costs and economic analysis.
 

The benefits include regional employment, relieving irrigation pressure on the unregulated Avon River and horticulture expansion in the Boisdale area. 

To support the delivery of the most recent Avon Valley Water Security Project feasibility study, we established a customer and stakeholder reference group in 2022 with stakeholders from across government, the Gunaikurnai Land and Waters Aboriginal Corporation, the environment and our customer groups from the Gippsland region including Macalister and Avon River customers. We are grateful for their time and expertise in providing advice and local knowledge to ensure project outcomes are technically sound.

In 2024, the Avon customer stakeholder reference group was consolidated with the Macalister Fresh stakeholder reference group. A number of workshops have been held in 2024 with the reference group and it is expected this group will be integral in this next phase of the project. We will also engage more widely with customers in the proposed area.

In July 2025, the Victorian Government provided funding to support the development of a detailed business case. The detailed business case will be conducted over 18 months between July 2025 and December 2026, and will take the project to capital ready stage.

The Avon Valley Water Security Project will be delivered in several phases. 

The project has now been consolidated with other projects in the Macalister Fresh consultation pathway. The Macalister Fresh project provides a vision for future irrigated development in the region through to 2050. Consultation through the Macalister Fresh project will inform the use of water savings from Macalister Irrigation District modernisation and provide a decision-making framework for future projects. 

The Avon Valley Water Security Project initial study area is situated east of the Avon River in farming land around Llowalong and along Freestone Creek.

The water resources assessment, in the most recent feasibility study, found Southern Rural Water channels have adequate spare volume to supply 6,000 megalitres per annum. However, there is limited spare channel capacity to meet peak demands, or most of the irrigation demands, during the peak summer demand periods.

The preferred water supply option only uses 50 megalitres per day of the maximum available 80 megalitres per day of spare channel capacity. This has the benefit of allowing continued flexibility of existing channel operation and any future requirements of the Macalister Irrigation District customers.

The Avon Valley Water Security Project is guided by a set of principles that aims to ensure decision-making is sound, equitable and protects existing users – this includes the environment. If the new supply is implemented, then it is anticipated current surface water use will decline, restoring natural flows to the Avon River.

The Avon Valley Water Security Project is guided by a set of principles that aim to ensure decision-making is sound, equitable and protects existing users – this includes cultural heritage values of the area. Where possible, we will seek to enhance cultural values and access to Country and its resources including water. 

A Cultural Heritage Management Plan is being prepared. We are in partnership with the Gunaikurnai Land and Waters Aboriginal Corporation to complete the field-based cultural heritage and values assessments that will inform the pipeline network design and future works.

Some preliminary fieldwork and assessment was undertaken in 2024. Previous modernisation projects have uncovered valuable cultural heritage.

We will investigate the impacts of increased irrigation as part of the technical works packages. Any future irrigation will need to comply with relevant legislation and the Irrigation Development Guidelines developed by the West Gippsland Catchment Management Authority to ensure best-practice irrigation.

We hope to understand the costs more clearly as we move from a concept design of the distribution network, and balancing storage to a functional design. Findings from recent work have indicated that design and construction costs would range from $46 to $53 million, depending on the route option selected. 

We will be developing a business case and through the process will determine more accurate cost estimates and will assess different funding models.

An estimated 30 gigalitres of water savings have been created through the phase 1 and 2 Macalister Irrigation District modernisation program. We propose that a proportion of this water could be used to supply the Macalister Avon Irrigation Project area. We will undertake modelling to determine the availability of these water savings under different climate scenarios.

This detailed business case intends to resolve the allocation of water savings, and will be undertaken in close consultation with the Macalister Irrigation District customers through the Macalister Customer Consultative Committee.
 

The most recent feasibility study found the Macalister Avon Irrigation Project area could be supplied via the Main Northern Channel system. The project scope is planned to improve the service to existing Macalister Irrigation District customers on the Main Northern system.