The Christchurch rebuild is expected to peak in 18 months time, with 14,000 jobs losses to follow over the following six years, according to a new Westpac report.
In the report, the bank said 80 percent of the 22,000 new jobs created in Christchurch since the earthquakes have been filled by locals.
Report author and economist David Norman said that meant there was a risk the city would be stuck with these workers, once the rebuild work runs out.
He said while Canterbury has experienced a record low unemployment rate of 3.4 percent, less than half the national rate, the loss of a large number of jobs in a short space of time would have a huge impact on the local economy.
Mr Norman said it was up to central and local government, as well as businesses, to retrain builders for other work and encourage new industry to the city.
"I would like to think that local and central government agencies are already thinking about this and what they are able to do to ensure that they attract other industries to the region, retraining and upskilling workers to move from the construction industry to other industries."
Mr Norman said newly-qualified construction workers could also be encouraged to move to Auckland, where demand for builders is expected to remain strong.