What is the SRW MID2030 modernisation project?
A key focus of the MID2030 Project has been to replace the Macalister Irrigation district’s ageing channel irrigation network with a modern piped system.
The Project was broken into phases to focus on work that would bring the greatest value in water savings and service improvements. The MID2030 Phase 1A project began in 2013 with works completed in 2017. Other stages planned under MID2030 are Phase 1B (2017- 2020) and Phase 2 (commenced in 2020 and is nearing completion).
Phase 1A has been incrementally audited since 2014. A final cumulative long-term water recovery audit was undertaken in late 2023 to confirm the final volume of water recovered from Phase 1A (approximately 13.3 GL).
Further information on the MID2030 modernisation project can be found at Macalister Irrigation District Modernisation | Southern Rural Water (srw.com.au) or at Investment in irrigation efficiency (water.vic.gov.au).
Why did the MID 2030 Modernisation project need to provide mitigation water to the environment?
Sometimes water in irrigation channels is discharged through outfalls and into wetlands and rivers, and provides an important environmental benefit. Improving the efficiency of the irrigation systems can reduce the volume of water that is spilled through these outfalls.
To mitigate this impact to the environment, SRW was required to develop Environmental Watering Plans (EWP) as per the Victorian Government Water Savings Protocol. The EWPs assessed environmental values and calculated the expected volume of mitigation water required to offset the impact of the implementation of the MID2030 Project. The EWPs identified that a volume of 1,814ML Long Term Average Annual Yield (LTAAY) is required to offset the impact to the Thomson and Macalister Rivers from the Project. This volume has been set aside as mitigation water, from the overall volume of water recovery achieved and audited by the project to date.
What has the VEWH requested?
The VEWH submitted a request to the Minister for Water, under section 48C of the Water Act 1989, for an environmental entitlement. The proposed environmental entitlement provides the VEWH with ongoing access to 1,814 ML LTAAY to be used at sites where an EWP identified that mitigation water was needed as a result of the MID2030 project. This volume converts to a 1,568 ML high-reliability water entitlement and a 691 ML low-reliability water entitlement. The proposed environmental entitlement also outlines, among other things, that the VEWH and SRW must prepare operating arrangements for the supply and use of this water.
How will the water be used?
The water will be used at sites where the MID2030 Project identified a need to mitigate impacts to local sites of high environmental significance. Specifically, the water will be used to meet ecological and hydrological values as identified in EWPs for the Thomson and Macalister Rivers.
The VEWH will work with the West Gippsland Catchment Management Authority to plan how the water is used each year.
Each year Catchment Management Authorities prepare Seasonal Watering Proposals. These are informed by community consultation, including consultation with local Traditional Owner groups, and consider local conditions. These proposals inform the Seasonal Watering Plan prepared by the VEWH each year. To ensure the water is used to get the most benefit, the VEWH considers advice from the Catchment Management Authorities and uses their local knowledge to inform its decision on how mitigation water will be applied.
How is water sourced to meet the new entitlement?
To ensure the issue of a new mitigation water environmental entitlement does not have an impact on existing entitlements in the Thomson/Macalister system, water recovery associated with MID2030 Project, including mitigation water, has been independently audited to ensure the entitlement being issued reflects actual water savings that have been achieved.
Total Project water savings are the total (gross) volumes saved, less the volume of mitigation water required.
What is the Water Savings Protocol and how is it used to calculate water recovery?
All water savings from major irrigation modernisation projects in Victoria, including the MID 2030 Project, must be estimated and audited in accordance with the Victorian Government Water Savings Protocol. The Water Savings Protocol is the technical manual for how to estimate water savings. It reflects current best practice for the estimation of water savings and is updated periodically to reflect improvements in technology and any changes in the understanding of irrigation system losses. It also sets out roles and responsibilities and specifies the audit process.
Estimating water recovery using the methods in the Water Savings Protocol ensures that the estimate is calculated in a consistent and transparent manner using the most current scientific information. This means it can be used as evidence to issue water recovery as entitlements.
The audit process requires an independent auditor to verify that the water savings estimates have been estimated consistent with the methods described in the Water Savings Protocol. The audit process provides confidence that the water savings are being estimated correctly.