In the regions, the influx is causing different problems, with infrastructure like car parks and toilets straining under the load.

Volcanic Plateau

At the 19.4-kilometer (12-mile) Tongariro Alpine Crossing, a track through a World Heritage Area on the central North Island volcanic plateau, thousands of tourists are overwhelming facilities designed to be used by a few hundred people a day.

In Glenorchy, near Queenstown, where Ngai Tahu offers jet-boating, canoeing and horseback trail rides, the company is forced to bring in chemical toilets during peak season because the small town’s waste-water facilities are insufficient.

There’s a similar issue at Franz Josef, the South Island township near the spectacular glacier of the same name, where untreated sewerage was pumped into a nearby river after a surge in tourist numbers.

The overloading is fueling concern that a bad tourist experience will harm New Zealand’s clean-green image and dent an industry that earned NZ$14.5 billion ($10 billion) from foreign visitors last year -- a fifth of all export receipts.

Funding the infrastructure that’s required is now sparking debate.

Remote Attractions

Many of New Zealand’s natural attractions are remote, and the nearest towns don’t generate enough local taxes to pay for the car parks and rest stops visitors need.

Regional councils this week estimated NZ$1.4 billion needs to be spent on tourism infrastructure to keep pace with demand. The government, which disputed that figure, has allocated NZ$17.5 million. The association representing tourism operators wants more, noting that foreign tourists contribute NZ$1.15 billion annually to the government’s coffers in sales taxes alone.