Former Barwon Downs borefield extraction bores to be decommissioned

The former Barwon Downs borefield extraction bores will be decommissioned in the coming months.

Barwon Water has engaged a qualified driller to carry out the works, which are expected to begin in November.

Last used in 2016, the former Barwon Downs borefield was crucial in servicing the region during the millennium drought, when Geelong’s water supplies fell to as low as 14 per cent.

Decommissioning the bores is in line with Barwon Water’s commitment to facilitate the recovery of the Lower Tertiary Aquifer and increase its focus on the use of alternative water sources.

Managing Director Shaun Cumming said the organisation was diversifying the region’s water supplies to reduce its reliance on rivers and groundwater.

“As our region grows and we experience more unpredictable conditions, we must deliver innovative, sustainable and affordable solutions, such as recycled water,” Mr Cumming said.

“The use of recycled water in applications like irrigation and industry means we can gradually return more water to the environment, helping to increase the resilience of our waterways.”

The Barwon Downs borefield is in the foothills of the Otway Ranges, about 30 kilometres south-east of Colac.

Barwon Water acknowledged in 2017 that the use of the borefield had led to a reduction in groundwater flows into select reaches of Boundary Creek, a tributary of the Barwon River.

A Remediation and Environmental Protection Plan (REPP) was then created to improve water flows, water quality, vegetation and ecology in Boundary Creek and Big Swamp.

The REPP’s 2023/24 Annual Report notes the progress that Barwon Water has made, with aims achieved at a number of individual locations.

“The remediation works are tracking well, with a number of targets met and others well on the way,” Mr Cumming said.

“Pleasingly, our extensive monitoring shows that currently no contingency measures are required to maintain this progress.”

The long-term recovery and re-pressurisation of the Lower Tertiary Aquifer system continues to yield positive results, with monitoring bores installed in the Lower Tertiary Aquifer on track to meet their respective targets.

About 390 million litres of supplementary water was released into the upper reaches of Boundary Creek in 2023/2024, helping to maintain flows in the lower reaches of the creek during the drier months and support wetland species within Big Swamp.

Thirteen of 15 groundwater monitoring bores installed within the Big Swamps Upper Aquifer system met or exceeded their water level target, with the other two meeting their mark some of the time.

Mr Cumming thanked the community members and stakeholders who had contributed to the development and implementation of the REPP over the past five-and-a-half years.

“Reference group members have had a strong influence on the remediation process, and we’re excited to continue working with them as we deliver further improvements in the natural environment.”

Southern Rural Water has recently accepted Barwon Water’s updated REPP, which uses the latest information to guide future actions and targets.

The full Annual Report 2023/24 for the REPP is published on the project page at www.yoursay.barwonwater.vic.gov.au/boundary-creek

Boundary Creek.