What was the aqueduct used for?
The aqueduct was constructed between 1913 and 1915 as part of Geelong’s first sewerage scheme.
The scheme was designed in 1911 by Robert T McKay, Chief Engineer for the Geelong Municipal Waterworks Trust (a predecessor to Barwon Water). The scheme was designed like a tree, with a main trunk fed by progressively smaller branches, and was considered highly modern at the time when compared to larger sewerage systems around the world.
Another modern feature of the sewerage network was the use of ovoid pipes. Made of reinforced concrete and shaped like an egg resting on its pointy end, the ovoid pipes allowed for sewage – regardless of its volume – to flow efficiently under gravity.
The most visible and spectacular part of the Geelong sewerage scheme was the aqueduct across the Barwon River plain at Goat Island. The design was inspired by the famous and iconic Forth railway bridge in Scotland. The reinforced concrete structure consisted of 12 cantilevered spans, with the sewer pipe suspended below.
The aqueduct was decommissioned in 1992 when a new sewer pipeline was built under the river.
Why is the aqueduct in an unsafe condition?
The aqueduct is 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.
Significant deterioration has been a problem since the mid-1970s and was a factor in Barwon Water’s decision to cease using the aqueduct in 1992.
Since then, investigations into improving, stopping or slowing further degradation of the heritage-listed structure have been unsuccessful.
Who will manage the proposed park?
It is likely Barwon Water will manage Aqueduct Park once safety and parkland establishment works are completed.
In the longer term, management of Aqueduct Park may move to one of the other existing parkland managers in the area.
Barwon Water may continue to manage the aqueduct structure.
What is the heritage significance of the aqueduct?
The aqueduct was added to the Victorian Heritage Register in 1991 as a significant example of early engineering design using reinforced concrete.
The structure is significant for its architecture, which was derived from the Firth of Forth Bridge in Scotland. It is also a remnant of one of Victoria’s earliest sewerage systems.
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 river and land either side of the aqueduct.
Concrete regularly falls from the structure and poses a serious safety risk. There is also a risk of structural collapse.
These safety issues need to be resolved for development and use of the river and proposed parkland.
The only way to re-open river access is to remove spans over the river. It is not technically or financially viable to repair any part of the existing structure to a safe condition.
Barwon Water, Heritage Victoria and the Barwon River Parklands Steering Committee have investigated a range of potential methods to restore the integrity of the structure.
There are methods available to slow further decay of the aqueduct, however, these are prohibitively costly (in excess of $18 million). This would not resolve the safety issues or negate the need to remove the spans over the river.
There are no methods available to reverse the current degraded state of the aqueduct or restore it to a safe condition allowing river access.
Installation of steel propping under the remaining spans will extend the life of the structure, although access under, and on, the structure will continue to be prohibited to protect public safety.
What is the site’s environmental significance?
The site hosts a healthy and diverse range of freshwater and saline wetlands and native vegetation.
The area is home to a variety of flora and fauna, including rare and threatened bird species such as the brolga.
This provides an important connection for fauna species moving along the Barwon River between the Ramsar listed wetlands of Lake Connewarre and Port Phillip Bay.
How will the project be funded? Will it impact water bills?
There will be no impact on Barwon Water bills.
Barwon Water is currently consolidating several buildings and land holdings. Barwon Water plans to direct some of the revenue from this process to the aqueduct project.