Tender advertised to reduce risk of flooding at Gong Reservoir

The City of Ballarat has advertised a tender for the design and construction of the Gong Reservoir wall in the Buninyong Botanic Gardens. 

The Gong Reservoir wall project aims to protect Buninyong residents by reducing the risk of flooding. 

Council last year voted to adopt the Buninyong Botanic Gardens Landscape Masterplan. The Masterplan included the design and reconstruction of the Gong Reservoir wall, taking into consideration recommendations made in the engineering peer review, conducted by Stantec in 2023, and the Landscape Masterplan. 

The leaking Gong Reservoir wall was identified as a public safety risk in 2019.  

Wall failure could mean flooding downstream, impacting the Botanic Gardens, the bowling club, primary school and private residences. An independent risk assessment recommended the City of Ballarat ‘take measures to reduce the overall risk’. 

An engineering solution was developed to stabilise the wall and a 27 May 2020 Council resolution recommended that a landscape masterplan be created to integrate the reconstructed Gong Reservoir into the surrounding landscape. 

Proposed wall remediation works, recommended by an experienced dam engineer, include the construction of an internal sand filter to control seepage through the wall. 

City of Ballarat Mayor, Cr Des Hudson said the Gong dam wall was important to residents, both as a thoroughfare and as a protected heritage asset.  

“The Gong Reservoir wall reconstruction will stabilise the wall and provide peace of mind for residents,” he said. 

“The landscape treatments will improve integration of the dam into the gardens showcasing an indigenous and native garden. 

“The project team will engage with stakeholders throughout the process, including Heritage Victoria and nearby residents to update them on developments and address any questions.” 

The works also enable the controlled discharge of the seepage water into the garden ponds.  

A landscaping design response to the works includes re-use and redevelopment of the stone retaining wall, at the base of the wall on the gardens’ side, planting of suitable species, new garden beds with low growing plants, fencing and bollards. 

It also includes a boardwalk for access to the Gong Reservoir and new paths and crossing points for pedestrians. 

The Buninyong Botanic Gardens Landscape Masterplan was informed through extensive community consultation and stakeholder engagement in 2021 and early 2022, including both a pre-engagement and a draft engagement landscape masterplan phase. 

The final draft masterplan was completed in early 2022. 

The flood mitigation project has already moved through the preliminary design phase. 

The tender advertises for a design and construct contractor which will be responsible for developing the design on behalf of the City of Ballarat, and then overseeing construction through to completion.