What is the Ovoid Sewer Aqueduct?

    The Ovoid Sewer Aqueduct is a 756-metre, multi-span bridge structure that crosses the Barwon River at Breakwater, south of the centre of Geelong.

    What was the aqueduct used for?

    The aqueduct was constructed between 1912 and 1915 and used to carry the Geelong outfall sewer across the Barwon River. The aqueduct was decommissioned in 1992 when a new sewer pipeline was built under the river.

    What is the heritage significance of the aqueduct?

    The Ovoid Sewer Aqueduct was added to the Victorian Heritage Register in 1991 as a place of architectural, historical, scientific (technical) and aesthetic significance to the State of Victoria.

    The aqueduct was a significant example of early engineering design using reinforced concrete - an innovative method promoted by French engineer Armand Considère. 

    The structure is significant for its architecture, which was modelled after the Firth of Forth Bridge in Scotland. It is also a remnant of one of Victoria’s earliest sewerage systems.

    What is the site’s environmental significance?

    The area surrounding the aqueduct is a large floodplain site containing a wide variety of vegetation and habitat types. Much of the native vegetation has recolonised following the exclusion of cattle grazing in 2001 and now supports a range of native, migratory and pest species. 

    The water regime is linked closely to the Barwon River. It involves a natural wetting and drying cycle and supports a wide variety of wetland vegetation types and aquatic species. 

    The range of species would have contributed to the rich existence of the Wadawurrung People living on and along the Barwon River, prior to European colonisation. The Traditional Owners would have used plants and animals as materials, for food and as different forms of medicine.

    The conservation and management of this site is likely to become more important over time, as urban development increases.

    Why is the aqueduct in an unsafe condition?

    The aqueduct suffered from structural failures since soon after its construction, largely as a result of the construction method that was used. 

    The aqueduct is now more than 100 years old. 

    Over time, moisture and air has penetrated the outer concrete casing and corroded the internal steel reinforcement. This has weakened the overall integrity of the structure and caused the shedding of large pieces of concrete. 

    The ongoing repairs of the aqueduct’s structure did not prevent the continued deterioration of the structure and was a factor in Barwon Water’s decision to cease using the aqueduct in 1992. 

    Decay of the structure has continued since decommissioning, including ongoing loss of concrete cover and exposure of the reinforcing steel, a process which ultimately will result in structural failure of the structure.

    What is Barwon Water doing to manage safety?

    The risks posed to the public by falling pieces of concrete and the potential for collapse of the aqueduct structure led to a decision in 1995 to fence the structure and close to the public the Barwon River around the aqueduct. 

    It is critical for everyone’s safety that they observe the signs and fences instructing them not to pass under the aqueduct along the river or land. The structure can shed large pieces of concrete at any time, which poses a critical safety risk to people due to the falling debris.

    In partnership with the Corangamite Catchment Management Authority (CCMA), Barwon Water has installed additional signage along the riverbank surrounding the aqueduct to deter community members from travelling under the structure.

    What is Barwon Water proposing to do with the aqueduct structure?

    Barwon Water has applied to Heritage Victoria for a permit to remove four of the 14 spans of the heritage-listed Ovoid Sewer Aqueduct in Breakwater, which has been rapidly deteriorating in condition since the 1970s. 

    As part of the application, we are proposing to retain the concrete bases of the four pylons to be removed as markers in the landscape, and secure the remaining structure with a new exclusion fence to prevent people from climbing on or under it. 

    This option would provide safe public access along the Barwon River and its banks, is cost effective (maintaining our commitment to affordable bills) and respects Aboriginal cultural values and the unique heritage of the 100-year-old structure (as most spans will remain). 

    The remaining structure will be fenced off and allowed to decay naturally over time, as a ‘standing ruin’.

    Why did Barwon Water revise plans to reduce the number of spans to be removed from five to four?

    Heritage Victoria requested more information after Barwon Water submitted its proposal in early March 2020.

    Heritage Victoria’s request for information asked for further investigation into options including retention of piers and pads from the piers, further explanation around budget limitations, and some technical detail. 

    In responding to that request, we Barwon Water refined its application to reduce the number of spans it is seeking to remove from five to four. 

    The application seeks the right balance between the critical safety need to remove spans, safe public access to enjoy the river and 66-hectares of surrounding land and the heritage values of the aqueduct. 

    The refinement of the application will still allow safe public access on river and on land, and retain more of the historic structure within what will become public open space that will be valued for its Indigenous and European cultural, historic and recreational values into the future.

    Will Barwon Water restrict public access to the remaining structure?

    As part of our proposed works we would secure the remaining structure with a new exclusion fence to prevent people from climbing on or under it.

    What will the proposed work on the aqueduct cost?

    It is estimated Barwon Water’s proposed management option for the aqueduct will cost approximately $3.5 million.

    Why is partial removal of the aqueduct necessary?

    Access under the structure is unsafe and has been prohibited since the 1990s. This prevents movement along the Barwon River, both on the water and by land. 

    Concrete regularly falls from the structure and poses a serious safety risk. There is also a risk of structural collapse. 

    The application seeks the right balance between the critical safety need to remove spans, safe public access to enjoy the river and 66-hectares of surrounding land and the heritage values of the aqueduct.

    Did Barwon Water consider other options?

    We investigated all possible options for improving, stopping or slowing the aqueduct’s natural degradation, particularly across the river. However, technical advice confirms it is simply not viable from a safety and cost perspective to retain the structure over the river, with full restoration costing in excess of $20 million.

    In determining the best solution to a very complex problem, the works proposed by Barwon Water have balanced a range of competing factors:

    • Valuing the heritage significance of the aqueduct structure and the desire to retain as much of the structure as possible. 
    • Acknowledging the Aboriginal cultural values of the land and river surrounding the structure, including the desire of the Traditional Owners to re-open access along the river to recognise its important role as a ‘cultural highway’.
    • Ensuring safety of users of the Barwon River and surrounding land and Barwon Water staff from falling debris or ultimate collapse of any part of the aqueduct structure.
    • Ensuring the cost of any proposed works does not impact on customer bills and service delivery. Any solution must be financially achievable within operating expenditure, including the cost of ongoing maintenance.
    • The strong desire of many groups to open up public access along the Barwon River, as well as opening access to the 66 hectares of adjacent land to the broader community.
    • The feasibility of implementing a solution that ensures all safety and cost constraints are met, and deals with the complexities of being in a floodplain where river levels can impact structures and stability.

    Our proposal aims to balance the complex and competing interests of a number of stakeholder groups, as well as providing certainty, security and longevity in resolving the long running issue of the aqueduct structure.

    When will a decision be made on the application?

    We expect a decision from Heritage Victoria mid-2020, subject to their review process. For more information on the decision-making process, please contact Heritage Victoria by emailing heritage.permits@delwp.vic.gov.au

    What is happening with the land surrounding the aqueduct structure?

    The aqueduct divides 66 hectares of Barwon Water-owned land, and as part of the plan to make the area safe, Barwon Water would like to create an area that is unique for its high ecological, historical, cultural and recreational values.

    As part of exploring opportunities for opening the surrounding land to the community, Barwon Water has been working together with Wadawurrung Traditional Owners to identify the Aboriginal cultural values of the river and area.

    In partnership with Wadawurrung, Barwon Water would like to gather information about the landscape and water, and engage other interested stakeholders to develop a plan for the area.