Mobilising labour for the Canterbury rebuild presents the greatest labour-market challenge in a generation, the Ministry of Business, Innovation and Employment says.
''It will create an unprecedented demand for construction workers and those in supporting industries.''
In the latest quarterly labour market report, the ministry said the Canterbury rebuild would require many thousands of additional construction workers at its peak.
The most in-demand construction-related occupations were carpenters and joiners, paint trade workers, plasterers and concrete workers.
The rebuild was likely to to be done over many years. Such factors as continued aftershocks had reduced the prospects of a faster rebuild.
The largest component of the construction effort related to rebuilding and repairing the many thousands of residential properties, the ministry said. The extensively damaged central business district might also take many years to rebuild.
''In contrast, land remediation and infrastructure repair are well under way. Both will require fewer, more specialised workers.''
While construction workers dominated the required labour pool, a wider pool of talent was required, including support staff and services workers.
The economic stimulus that would follow the arrival of new workers would, in turn, drive employment growth in other sectors such as hospitality and retail.
The local population could supply labour directly for the rebuild or indirectly by supplying supporting services. Other industries could also supply labour, the ministry said.
As labour from other industries was drawn towards rebuild activities, the ministry expected some small generalised increase in wages within the region as other sectors sought to retain labour.
That was the experience of the mid-2000s construction boom when construction workers were sourced from the manufacturing sector.
Construction-sector wage growth in Canterbury continued to be stronger than in the rest of New Zealand.
The ministry expected migration from within New Zealand to be a key source of labour for the rebuild, but external migration would also play a part.
The ministry monitored short-term visitor arrivals, and the visa programme, to understand the impact of migration from outside the country.
ASB economist Jane Turner said the Canterbury rebuild remained a key drawcard for permanent and long-term arrivals, with arrivals in Canterbury up 49% on a year ago.
More recently, the slowdown in the Australian economy had resulted in a strong rise in New Zealanders returning home. As a result, arrivals in Auckland had risen in recent months.
Migration figures released yesterday by Statistics New Zealand showed seasonally adjusted net migration of 1980 for July and 10,570 for the 12 months to July.
Ms Turner said departures had steadily fallen, particularly to Australia. With the mining investment boom starting to slow, labour demand there had eased and unemployment was edging higher.
In contrast, the outlook for New Zealand's labour market was for gradual improvement.
