Building Queensland
Damien Gould, Chief Executive Officer

Building Queensland has released the Nullinga Dam and Other Options Preliminary Business Case. The preliminary business case investigated the potential for Nullinga Dam and other options to address the identified future water supply shortfall to service growing urban demand in Cairns and to stimulate irrigated agriculture in the region by supplementing existing supplies.

The preliminary business case considered four shortlisted options:

  • option 1: do minimum—continuation of water trading and on-farm efficiency measures in the Mareeba Dimbulah Water Supply Scheme
  • option 2: improve the Mareeba Dimbulah Water Supply Scheme rules and operations to increase operational performance and reduce current constraints
  • option 3: modernise the Mareeba Dimbulah Water Supply Scheme distribution system via infrastructure works to reduce system losses and convert certain loss allocations into new water allocations for sale
  • option 4: design and build Nullinga Dam for agricultural use initially for delivery of water to Walsh River customers within and downstream of the Mareeba Dimbulah Irrigation Area.

The preliminary business case, provided to the former Department of Energy and Water Supply in 2017, recommended that options 2 and 3 progress for further evaluation. Option four was not recommended until a satisfactory level of certainty of demand was met.

Since completing the preliminary business case, industry has provided information that has satisfied the triggers based on potential demand to progress to a detailed business case. The detailed business case will further investigate the construction of Nullinga Dam and improvements to the existing water supply scheme. Building Queensland expects to commence the detailed business case soon.

Building Queensland is committed to enhancing rigour and transparency of analysis in business cases. The Nullinga Dam and Other Options Preliminary Business Case is the third business case to be publicly released by Building Queensland. It follows the release of the Lower Fitzroy River Infrastructure Project Detailed Business Case last month, along with business case summaries and cost benefit analysis summaries for the Smithfield Transport Corridor Upgrade and the Beerburrum to Nambour Rail Upgrade.

Read the Nullinga Dam and Other Options Preliminary Business Case