A WA Government infrastructure report has revealed a long-promised new youth detention centre at Banksia Hill will not be ready until 2028 — a delay suicide prevention advocate Gerry Georgatos says is "just another betrayal" by the state's Department of Justice.

"It's been one betrayal after another … and to be told it won't be ready until mid-2028 means it will probably be 2030," Mr Georgatos told National Indigenous Times.

In 2022 the McGowan government announced a 30-bed facility - the New Youth Detention Facility (NYDF) - as a replacement for Unit 18 at Casuarina Prison.

The maximum-security adult jail has been housing children since 2022, when Unit 18 was opened as a stop-gap after repeated crises at Banksia Hill.

The new centre was originally slated for completion in 2026.

Infrastructure WA has since warned the project faces "a risk of delays to the program associated with the need to secure state and federal environmental approvals, which can take between nine and 24 months".

It also flagged "current construction sector pressures" and said "key stakeholder acceptance of the proposal has not yet been fully tested, particularly in relation to Aboriginal communities and oversight bodies".

Valued at $156.84 million, the facility was labelled an "undesirable necessity" by Infrastructure WA, with the promise of delivering more effective rehabilitation programs.

Mr Georgatos rejects that claim, calling the centre "much of the same, holding pens and corrals of human misery".

He said similar assurances were made about Unit 18, which was described as state-of-the-art but instead became a site of isolation, riots, record levels of self-harm and the death of 16-year-old Cleveland Dodd in 2023.

In August 2024, a 17-year-old boy also died at Banksia Hill, just two days after arriving.

Mr Georgatos argues the focus should be on people, not buildings.

"We need nurturers, seasoned experts, psychiatrists, psychologists, impairment specialists," he said.

"Instead, we're getting guards re-badged as mentors."