Contractors have begun clearing trees on the river's south bank to create an assembly area for the curved portion of the two-lane, 250m-long bridge.
The bridge will replace the 91-year-old single-lane bridge which links the resort to the Remarkables Ski Area, Southland and Fiordland.
NZ Transport Agency senior project manager Phil Dowsett said over the next two months a temporary steel structure would be built from the south bank, into the deepest part of the river, to allow piling and concrete construction of the first two piers.
Once the bridge's curved portion was assembled, it would be lifted on to the new piers using two 150-tonne cranes.
Preparatory work would begin on the northern bank once overhead power lines crossing the river were rerouted underground and across the existing bridge.
Traffic signals on the northern approach to the old bridge would be moved up the hill towards Southberg Ave to create a working space on the north bank, Mr Dowsett said.
Lead contractor McConnell Dowell Constructors is expected to complete the project by spring next year. The old bridge will become part of the Queenstown Trail cycling and walking network.
