Premier Annastacia Palaszczuk told parliament on Tuesday the new desalination plant be delivered by 2035 after cabinet endorsed a 30-year water security plan.
There are also plans to expand the Gold Coast's desalination plant by 2033.
"A detailed business case for the new desalination plant will be completed for budget consideration in 2025," Ms Palaszczuk said.
"The precise location of the desalination plant is yet to be determined and will be reliant on the business case."
Ms Palaszczuk said the water security plan was completed with Seqwater, Queensland's bulk water supply authority, and focuses specifically on desalination to bolster the state's water supply in the face of climate change and natural disasters.
The government has also committed to constructing a new water treatment plant by 2033 and connecting Wyaralong Dam in the Scenic Rim region to the main Seqwater grid.
Water Minister Glenn Butcher said the grid must be prepared for booming population growth combined with climate challenges.
"It's a 30-year plan that considers population growth, projected rainfall and climate change to determine what new water infrastructure is needed and when we will need it," Mr Butcher told parliament.
"Considering the dual challenges of creating a resilient water supply and meeting demand from population growth here in Queensland, Seqwater will also undertake a detailed business case for a new desalination plant in southeast Queensland."
Mr Butcher said Seqwater's modelling showed the proposed new desalination plant wasn't required until the mid-2030s but the government was keen to begin planning early.
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