Up to 200 staff and 420 inmates at Wellington Correctional Centre will be relocated to other prisons by the end of the month due to the ongoing effects of Western NSW's mice plague.
Corrective Services NSW Commissioner Peter Severin said temporarily scaling back operations at the centre was the best resolution to the challenges presented by the plague.
"The health, safety and wellbeing of staff and inmates is our number one priority so it's important for us to act now to carry out the vital remediation work," Mr Severin said.
"The staff at Wellington have done an incredibly good job in managing the effects of the mice plague, but we need to take this step now to ensure the site is thoroughly cleaned and infrastructure is repaired.
"I thank the team at Wellington for their ongoing commitment to their work during this challenging time."
Most staff will be redeployed to other correctional centres in the western region, while a skeleton crew remains at Wellington to oversee and contribute to remediation work.
About 420 male and female inmates will be transferred to other prisons in the next 10 days while the cleansing and remediation work takes place.
Inmates will be transferred to a number of sites including Macquarie Correctional Centre, where normal operations continue. Some of those inmates will return to Wellington during the day to work.
The mice have caused damage to internal wiring and ceiling panels. Removing as many staff and inmates as possible will expedite the remediation works.
Assistant Commissioner Custodial Corrections Kevin Corcoran said the remediation work would include investigating ways to protect the centre from future mice plagues.
"We want to do this overhaul once and we want it done properly, which means we'll be looking at ways to mitigate the effects of similar plagues in the future," Mr Corcoran said.
"Relocating staff and inmates will give us the best chance of deep-cleaning the prison, reviewing site infrastructure and tackling this challenge head-on."
In-person visits to Wellington Correctional Centre will be put on hold until the remediation work is complete.