Balickera Tunnel remediation

Hunter Water is carrying out rehabilitation of the Balickera Tunnel to ensure ongoing reliable transfer of water from the Williams River to Grahamstown Dam via the Balickera Pump Station.

The 1.2km tunnel was constructed in 1962 and is a key piece of the region’s water supply infrastructure.

Contractors Abergeldie are carrying out the following work on behalf of Hunter Water:

Upgrade to existing access tracks

Monday 1 November to December 2021, weather permitting

  • Building temporary site offices, upgrade of existing access tracks and lay down areas along the canal.

Tunnel rehabilitation works

December 2021 to April 2022, weather permitting

  • Building a temporary dam downstream of the tunnel, and temporarily dewatering the tunnel for remedial works
  • Entering the tunnel to remove loose rocks and reinforcing the tunnel walls to provide long term structural stability
  • Restoring some areas of the site once work is complete.

The access tracks we are upgrading along the banks of the canal will remain for future operational requirements.

View the environmental assessment documents placed on public exhibition

Environmental assessment

Balickera tunnel is a known roost site for a number of threatened microbat species and the remediation work is likely to have a biodiversity impact on these colonies due to temporary exclusion from the tunnel. The affected species are listed as ‘Vulnerable’ under the NSW Biodiversity Conservation Act 2016 (BC Act) and include:

  • Little Bent-winged Bat (Miniopterus australis)
  • Large Bent-winged Bat (Miniopterus orianae oceanensis)
  • Southern Myotis (Myotis macropus).

We carried out an environmental assessment which included an assessment of biodiversity. A Species Impact Statement was prepared to support the Review of Environmental Factors. The Species Impact Statement and Review of Environmental Factors were placed on public exhibition between Friday 13 August and Friday 10 September 2021 (28 days).

All feedback from this public exhibition was considered and a Submissions Report was prepared. This report formed part of a submission to the NSW Department of Planning, Industry and Environment (DPIE) for their concurrence.

We received concurrence for the Species Impact Statement on 19 November 2021 and works to remediate the tunnel has started.

Managing impacts during remediation work

We will be temporarily excluding all bats from the tunnel while the remediation work is carried out. This will be for approximately four months.

The Species Impact Statement includes a Microbat Management Plan prepared by the project ecologist and includes requirements for pre-construction, during construction and post-construction.

During preparation of the Species Impact Statement and consultation with bat experts, it was identified that excluding the bats during summer would result in the least impacts to the bats. The Microbat Management Plan can be viewed in Appendix J of the Species Impact Statement.

To reduce impacts to the bats during construction, bat boxes have been installed in trees along Balickera Canal and surrounds. Additional locations for bat boxes are also being considered.

We will be carrying out intensive surveys to track the movement of the bats and their usage of other known roost sites across the region during construction, and quarterly for two years after construction to monitor their return to the tunnel.

Thirsty for more information?

Contact us if you would like to learn more about the Balickera Tunnel rehabilitation project.