Maximum security inmates at the Macquarie Correctional Centre in Wellington could still be able to spend up to six minutes in the shower when level four water restrictions come into effect on November 1.
"Inmate showers at Macquarie Correctional Centre use water-saving fittings and are capped at six minutes," a Corrective Services spokeswoman advised.
"The centre will explore reducing that further if level four water restrictions come into effect."
Law-abiding Dubbo residents will be effectively banned from spending longer than five minutes in the shower come November 1.
The Corrective Services spokeswoman said Wellington correctional complex was actively seeking to reduce its water usage.
Natural features like grass and plants were no longer watered following the introduction of level three water restrictions, she advised.
"The NSW Government is scheduled to conduct a water audit of both centres, which will assess total water resources, usage, storage, systems and additional water-saving options," the spokeswoman told Australian Community Media.
She said inmates at the Wellington Correctional Centre, which is located adjacent to the Macquarie centre, had showers capped at five minutes.