Two Christchurch women rescued by helicopter in Arthur's Pass National Park today were "very lucky" to be alive, after a series of foolish botches including walking into a dangerously flooded river using just a walking pole to stay together, rescuers say.

Police say they have the power to bill the trampers for their rescue, which involved a helicopter, but have not yet decided whether to do so.

Severe weather warnings for the area including rain and snow had been in place for several days, but the trampers - in their late 20s - claimed not to be aware of them, Search and Rescue Arthur's Pass spokesman Graeme Kates told NZPA.

After waking up in Goat's Pass hut to find it raining, they decided to head back across several rivers in flood. At the first crossing, Mingha River, they joined up using a walking pole.

"They weren't actually crossing it using any technique I would use," Mr Kates said.

Both were swept away about halfway across. While one quickly recovered and got to the other side, the other carried on about 200 metres, over rapids and small waterfalls, before she managed to scramble out and raise the alarm back at the hut.

However, after alerting police on radio, she cut the emergency call off halfway through, and turned it off, leaving police unsure of the situation. Because of the bad weather, they dispatched a helicopter, which found the two women at different huts on opposite sides of the river, with mild hypothermia and shaken up about 1.30pm today.

The one who had been swept the furthest also had minor head injuries, cuts and bruises, but neither needed medical treatment, Mr Kates said.

"She definitely went over quite a few bumps and got hit fairly hard."

He said the two were clearly novice trampers, who made several errors.

"They obviously walked into a flooding river as well."

His advice to trampers was to "always" get the most current weather forecast, "and certainly never walk into any river where you cannot see your feet on the bottom".

The women were very embarrassed and did not want to talk to media, he said.

"I think they were very lucky, given the situation."

Police also said the pair were "very lucky", with heavy rain and snow closing in as they were being rescued.

Sergeant Lindsay Turner said although police were funded by Government for search and rescue emergencies, they had the power to bill people rescued from situations where they had been at fault, but had not yet decided whether to do so in this case.

He did not believe there was a precedent for this in New Zealand.