Queensland has posted a surprise $1.5 billion surplus after Treasurer Jackie Trad handed down what she’s called a “responsible” first budget focusing on major infrastructure projects.

The operating surplus for this financial year will be $1.512 billion − three times that predicted in the mid-year budget review in December.

The extra money is almost exclusively from an excess of mining royalties, with coal and gas pumping $4 billion into the state economy in 2017-18, an increase of $1 billion on the amount predicted in the last budget.

And the surpluses will continue for the foreseeable future with the government forecasting $148 million in 2018-19, $160 million in 2019-20, $110 million in 2020-21 and $690 million in 2021-22.

Five new taxes will be introduced in 2018-19 − four of which target the wealthy − over the likes of luxury cars and foreign property investment, along with a $70-a-tonne waste levy.

The money will be put towards infrastructure, with $45.8 billion being spent on capital works.

The state government will also keep borrowing to help pay for the infrastructure spend, with state debt levels set to hit $83 billion by 2022.

However, Ms Trad has moved to reframe the debt debate, insisting the levels are manageable.

“Debt is stable, it is sustainable, and it is responsibly funding much-needed infrastructure for our communities and for our economy,” she told reporters on Tuesday.

“We make no apologies for borrowing to invest in infrastructure. It’s the right thing for jobs today, but it’s also critical for economic productivity in the future.”

Ms Trad also again took issue with focusing on the overall debt figure, saying actual government debt was more like $30 billion without the debt incurred by government-owned corporations like power companies that service their own debt.

Previous Labor treasurer Curtis Pitt was criticised for transferring around $4 billion of general government debt to government-owned corporations in his first budget, but Ms Trad promised she would play a “straight bat” with her figures.

The government’s infrastructure program is the biggest since 2011 when the state was hit by widespread major flooding.

The other major sectors of investment are health, with $18.3 billion, a billion of which is capital works, and $14.1 billion towards education.

Queensland households will get some bill relief with $5.6 billion in rebates to a number of costs including power.

The Great Barrier Reef has $330 million directed its way in a number of projects to improve water quality and address the effects of climate change.

The key points

• A $1.512 billion operating surplus posted in 2017-18, while a $148 million surplus is forecast for 2018-19

• Debt set to hit $83 billion by 2021-22

• $45.8 billion infrastructure program

• $18.3 billion health funding

• $14.1 billion for education

• $5.6 billion for rebates and other measures to ease cost of living

• $330 million for Great Barrier Reef programs

• Four new “luxury” taxes to raise $163 million a year

• New waste levy of $70 a tonne to raise $100 million in its first year

• $4 billion in resource royalties, around $1 billion more than expected.