Development of the southern supply to the ACT


For 2017 information about project consultation, please visit the ACT Second Supply Project page.

In 2009, TransGrid and ActewAGL conducted a regulatory test to explore options for meeting the ACT Government’s 2006 requirement to enhance the bulk electricity supply to the ACT. 

TransGrid and ActewAGL’s preferred option was for TransGrid to:

  • construct a new 300 kiloVolt (kV) switching station at Wallaroo on the NSW side of the ACT border 
  • re-reoute and extend the Canberra-Williamsdale 330 kV line to form a Wallaroo-Williamsdale 330 kV circuit
  • install a second 375 MVa 330/132 kV transformer
  • ActewAGL to upgrade the existing subtransmission lines between Gilmore and Theodore zone substations.

TransGrid and ActewAGL published Application Notices and Final Reports and received no stakeholder response to those documents. 

The ACT Government subsequently requested that the switching station location be moved from Wallaroo to Stockdill Drive on the ACT side of the border. TransGrid and ActewAGL have used the opportunity to refine the preferred solution to deliver a more optimal outcome, including greater diversity of supply, at a lower overall cost. 

TransGrid plans to commission Stockdill Drive by 2020.

Application Notices

Application Notice (Wallaroo)

Application Notice (Williamsdale)


Final Reports