A large hole for workers has been dug at the St Andrew St intersection, looking north along George St.
Workers are replacing underground pipes, some of which date back to the 1800s.
Upgrades began on the first block of the retail area in April last year.
The second block, on the corner of St Andrew St, is now being worked on.
Construction on the George St retail area is expected to cost more than $50million.
The project is expected to be completed in April next year.
REPORT: TIM SCOTT