The Waiho Bridge near Franz Josef will not be reopening on Friday, with work continuing into the weekend.
Contractors and engineers have been contending with rising river levels today as heavy rain poured in the Westland District. They have revised the estimated opening time.
The bridge, which is described as a lifeline for the district, was washed away in the floods two weeks ago.
Since then people have had to drive hundreds of extra kilometres to travel between the two towns or use a helicopter taxi.
The bridge structure was successfully rolled across the bridge piers to the north bank this afternoon but it cannot be fastened permanently until the river drops and work can start from the river bed.