A rethink is needed on Auckland's growth before it gobbles up Hamilton and runs down the regions, an economist says.

Photo: Google Earth

The Immigration Minister, Michael Woodhouse, has confirmed he will look later this year at new incentives to encourage immigrants to settle outside Auckland.

Photo: RNZ / Jane Patterson

Despite a chronic housing shortage, the city is predicted to grow by at least 30,000 people a year for the next 15 years.

BERL chief economist Ganesh Nana said the big picture would not be pretty.

"We would be looking at Auckland sprawling and probably gobbling up Hamilton," he said.

"We would be looking at a lot of our prime land and other resources being used for residential purposes, which is not bright."

Dr Nana said a sprawling Auckland would require more infrastructure at the expense of the rest of the country. He said, if nothing was done, the city's congestion would only grow.

To hear more about what Auckland's growing dominance means for the rest of the country, listen to the full investigation on Insight just after 8am on Sunday.