Boundary Creek and Big Swamp remediation
We are committed to the remediation of Boundary Creek and Big Swamp, addressing the impacts of historic groundwater extraction.
The Barwon Downs borefield has been a crucial back-up water source during periods of drought. In 2007, at the height of the worst drought on record, Geelong’s water storages dropped to just 14%. During this time, Geelong relied on the borefield to provide water.
Recent technical work has confirmed that intermittent use of this critical supply over the past 30 years – combined with the effects of a dry climate – has led to a reduction in flows to Boundary Creek and the subsequent activation of acid sulfate soils in Yeodene peat swamp (Big Swamp).
Working with a community and stakeholder group and a panel of independent technical experts, we are committed to developing and implementing a remediation plan to improve environmental outcomes for this catchment. This process is supported by the Victorian Government and legally enforceable through Section 78 of the Water Act 1989.
In March 2019, we withdrew our application to extract gropundwater from the Barwon Downs Borefield to focus fully on the remediation of Boundary Creek and Big Swamp, addressing the impacts of historic groundwater extraction.
Learn more and have your say at our dedicated microsite
We’ve set up dedicated microsite for the Boundary Creek and Big Swamp remediation process.
The site includes a comprehensive document library, frequently asked questions, news archive, discussion forum, and more.
Boundary Creek and Big Swamp
Boundary Creek is a tributary of the Barwon River. About 19 kilometres long, it flows east through Barongarook, and joins the Barwon River at Yeodene, about 16 kilometres south-east of Colac.
Big Swamp (also known as Yeodene Swamp) is a peat swamp on Boundary Creek. The swamp is located about 4 kilometres upstream from the confluence of Boundary Creek and the Barwon River.
Barwon Downs borefield
The Barwon Downs borefield (sometimes referred to as the Gerangamete borefield) was constructed in the 1980s in response to prolonged drought. A critical emergency water source for Geelong – and now Colac – it has been called upon five times since to supplement surface water storages. The borefield was last used in 2016 to boost supplies following a record dry summer.
The borefield consists of six bores that can pump groundwater from an aquifer, approximately 300 to 630 metres below ground level.
Relationship between groundwater pumping and stream flows
Technical investigations, and an enhanced monitoring program commenced in 2012, have confirmed that the intermittent use of the borefield over the past 30 years has contributed to reduced flows to Boundary Creek and Big Swamp. Specifically, data suggests that historic groundwater extraction is responsible for about two-thirds of the reduction in base flows, with the dry climate during the same period accounting for the remaining third. Studies have also confirmed that the drying of Big Swamp has activated acid sulfate soils in Big Swamp and subsequent releases of acidic water downstream.
We are committed to developing a comprehensive remediation plan for the Boundary Creek and Big Swamp environments, with a view to improving environmental outcomes for this catchment.
The remediation plan is being developed in consultation with a community and stakeholder group and a panel of independent technical experts nominated by the group.
Remediation working group and expert panel
In May 2018, we formed a community and stakeholder working group to assist is developing a remediation plan. The group includes representatives from:
- Corangamite Catchment Authority (CCMA)
- Colac Otway Shire
- Land and Water Resources Otway Catchment (LAWROC) land care group
- People for a Living Moorabool (PALM)
- Upper Barwon Landcare Group,
- Boundary Creek landowners
- Traditional Owners
- and other interested community members.
The remediation working group also benefits from the advice of three independent technical experts, nominated by the group:
- Dr Vanessa Wong, senior lecturer, School of Earth Atmosphere and Environment, Monash University
- Professor Richard Bush, Global Innovation Chair, International Centre for Balanced Land Use Office, Newcastle University
- Dr Darren Baldwin, independent consultant, visiting adjunct professor, School of Environmental Sciences, Charles Sturt University.
The technical panel is actively collaborating with the community and Barwon Water to develop and refine our remediation approach.
Section 78 Ministerial Notice and scope of works
In September 2018, Barwon Water received a directive from the Minister for Water, pursuant to Section 78 of the Water Act 1989. The notice directs Barwon Water to:
- prepare and implement a remediation and environmental protection plan for Boundary Creek, Big Swamp and the surrounding area, and
- discontinue any extraction activities (other than for maintenance and emergency response purposes) while the assessment is being completed and until all remediation work dictated under the remediation plan has been completed.
Barwon Water welcomed the notice for a legally enforceable remediation plan, noting that it had already been working proactively on activities consistent with these objectives.
In accordance with the notice, we submitted a scope of works to Southern Rural Water. The scope of works outlines the area that will be covered by the remediation plan, the environmental values to be included and the necessary environmental assessments and methodology proposed to develop the remediation plan.
In developing the scope of works, we considered:
- all appropriate hydrogeological, hydrological and geochemical assessments
- community feedback via the Boundary Creek and Big Swamp remediation working group and nominated expert panel
- feedback from Southern Rural Water’s independent technical review panel
- the State Environmental Protection Policy (Victorian Waters).