The government has stated that it will keep the facility open even though it currently runs at less than 20 per cent capacity and carries a $10 million bill annually.

Whitelion state manager Lyndon Stevenson said the juvenile justice organisation encouraged preventative programs.

He acknowledged Ashley as a "complex situation" but said it was important that at-risk people received early intervention and support.

Youth Network of Tasmania chief executive Joanna Siejka agreed, noting that recidivism rates for youths in juvenile detention ran at 80 per cent.

The youth advocacy group has extensively lobbied for alternatives to youth detention and was involved in the Children and Youth Service's inquiry into continuum of care last year.

She said the low number of youths in Ashley should be viewed as a positive and used in support for an alternative system.

"It's not an argument any more," Ms Siejka said.

Australian Lawyers Alliance spokesman Greg Barns said the decision to continue running Ashley was a reflection of the government's laziness.

"The government shows no real interest in real youth justice reform because Ashley is simply a prep school for Risdon and it's in the wrong place, its buildings belong in the wrong era and it doesn't in any way assist the people who go in there," he said.

Mr Barns said community-based detention had proven effects internationally.

"Incarceration should be used only as a last resort - there are very, very few cases where people of a young age should be detained."

Western Tiers MLC Greg Hall , who had previously chaired a committee reporting on the facility, said that while the group had strongly supported diversionary programs, it had recognised "there would always be a need for secure facilities".

He said the centre boasted top-class educational facilities and had proved important in keeping dangerous offenders out of the community.