Victoria will build a new youth prison in Melbourne on the current site where more than a dozen teens are still barricaded inside a unit.
After two nights of the rioting the state government announced it will expedite the rebuild of the Parkville youth justice centre, meaning some inmates will go to adult prisons for up to three years.
Before that happens, the young offenders will be moved out so damage to the Parkville facility can be fixed to make it usable again in the short term.
"The infrastructure at this Parkville facility is letting us down. It was built in the early 1990s and it is not fit for purpose," Children's Minister Jenny Mikakos told reporters on Monday.
Youths rioted on Saturday night and again early on Monday, with the second riot still going after teens barricaded themselves inside a unit.
"This behaviour is completely unacceptable and staff shouldn't have to put up with it," Ms Mikakos said.
New laws will be also introduced so teen prisoners who assault corrections officers will have that assault taken into account when they go before the youth parole board.
Opposition children's spokeswoman Georgie Crozier said Ms Mikakos had lost control of the youth justice system.
"(This) is the latest in a long line of violent incidents that are now happening multiple times a week at youth justice facilities," Ms Crozier said.
The teens involved in the latest riot are aged from 15 to 18 and are all on remand.
Community and Public Sector Union state secretary Karen Batt said staff were being traumatised thanks to assaults, riots and the damage done to the facilities.
"They're also protecting a number of clients that do not want to be part of this," Ms Batt told reporters.
"This is not every client inside the facilities, this is a number of hardened inmates who are creating the problems and the tensions within the system."
Ms Mikakos did not have a cost for rebuilding Parkville, but said it would take up to three years, and some prisoners would be held in adult prisons for that time.
Officials could also not reveal whether pizza delivered to the prison was for staff or inmates.
