Regional Water Infrastructure

Progress

Werribee Irrigation District Modernisation Project

The Werribee and Bacchus Marsh Irrigation Districts together constitute approximately 3,300 hectares of land to Melbourne’s west, directly generating agricultural outputs valued at more than $200 million per annum and supporting an estimated 1000 jobs. The business cases for the two districts identified an urgent need for irrigation modernisation in response to diminished water security for growers in a warmer climate that could adversely impact production and a modified hydrological cycle that placed greater stress on the flow of the Werribee river and its tributaries.

The work on the Werribee Irrigation District Modernisation Project commenced in 2016 and reached practical completion in December 2019. The replacement of approximately 23 kilometres of poorly performing open channels with a modern, automated pipeline improves productivity across the district and improves irrigation water quality (reduced salinity). A total of 103 outlets have been automated during the project now allowing Southern Rural Water to deliver enhanced service levels to support grower requirements. The project was delivered in full, however there remains an opportunity for further modernisation.

An interim water savings report submitted by Southern Rural Water indicates that around 3700 ML of water savings has been generated by the project (primarily achieved through avoided seepage from the old channels). Following a 12-month period of monitoring to quantify the water savings, an audit will be conducted in 2021 to assess the actual water savings achieved. It is anticipated that half of the water savings will then be made available to the district’s irrigators and the other half will be issued to the Victorian Environmental Water Holder that will allocate additional water to the flow stressed Werribee River.

During the construction stages of the project works, Southern Rural Water progressively adopted new operational arrangements to deliver water through the partially modernised system to ensure no irrigator was adversely impacted.

To fully achieve a modernised system for the Werribee Irrigation District, the State sought Commonwealth funding for stages 4 and 5 of the project to construct a further 16.2 km of pipeline and automation of 70 outlets.

Bacchus Marsh Irrigation District Modernisation Project

The neighbouring Bacchus Marsh Irrigation District Modernisation Project achieved practical completion in June 2020 and has replaced approximately 8.5 km of poorly performing channels with pipeline. Stage 1 involved the construction of a new pump station at Maddingley. Stages 2A, 2B and Stage 3 pipeline works included construction of 6.4 km of pipeline, automation of 4 outlets and decommissioning of 1 km of pipeline. Stage 4 works commenced in June 2019, delivering the construction of 2.75 km of pipeline and planned automation of a further 3 outlets.

Reconfiguration of the district has the additional benefit of being able to connect new customers to the system. The project was delivered in full, however there remains further opportunity to provide additional public open space in the township following the decommissioning of the Main Channel.

The interim water savings report submitted by Southern Rural Water indicates that nearly 800 ML of water savings has been generated by the project so far and it is on track to generate approximately 1000 ML in water savings. Following a 12-month period of monitoring to quantify the water savings, an audit will be conducted in 2021 to assess the actual water savings achieved. Similar to the approach for the Werribee project, it is anticipated that half of the water savings will be available to the district’s irrigators and the other half  will be returned to the flow stressed Werribee River.

During the construction stages of project works, Southern Rural Water progressively adopted new operational arrangements to deliver water through the partially modernised system to ensure no irrigator was adversely impacted.

The State sought Commonwealth funding toward stage 5 of the project which includes piping of approximately an additional 1 km of channel and decommissioning approximately 8 km of channel (the 'Main Channel').

South West Loddon Rural Water Supply Project

The South West Loddon project  constructed approximately 1,170 km of pressurised stock and domestic pipeline and has increased stock and domestic water access to the rural communities across 2,190 km² surrounding the town of Wedderburn. The project works included the connection of the Wimmera Mallee Pipeline to the Waranga Western channel to expand the Victorian water grid between the Wimmera-Glenelg and Goulburn systems. The project enabled a better quality raw water source to Coliban Water water treatment plants at Bridgewater and Laanecoorie, thus reducing extractions from the Loddon River. Furthermore, the project installed 49 new firefighting water access points to improve emergency water management in the region.

The project was delivered over two stages. Stage one of the pipeline was completed in December 2016.   Stage two included the construction of the remaining pump stations (14 in total). The final year of construction involved commissioning and system testing which was completed in March 2020.The completion of these works supports water security and reliability for the land managers of the region by allowing properties connected to the pipeline to meet their critical needs rather than relying on rainfall to fill their on-farm storages.

A cultural water study was funded by the project and completed by Dja Dja Wurrung. Cultural watering opportunities have been identified for potential future implementation. The development and implementation of a Memorandum of Understanding between GWMWater and the Dja Dja Wurrung was recognised more widely in 2018 being the winner of the Premier’s Sustainability Award in the Environmental Justice category

Many of the social benefits have already been realised, through connection of community facilities, sporting clubs and installation of firefighting water access points across the project area. Ongoing assessment of broader project benefits will be undertaken over the next five years.