Watching 12 activists - including an 88-year-old man - being arrested yesterday afternoon at a protest against dairy expansion in the Mackenzie Basin was "pretty moving'', Greenpeace sustainable agriculture campaigner Gen Toop says.

At daybreak 11 protesters locked themselves "on to diggers and machinery'' to be used in the construction of an irrigation pipeline for Simons Pass Station south of Lake Pukaki.

Before 2pm, police at the scene started making arrests.

"The thing is industrial dairying has been polluting our rivers for a long time - and our climate and trashing our landscape. And we have been campaigning for a long time on this, many New Zealanders for decades, raising concerns about this - and we are just not being listened to,'' Miss Toop said.


"We've got to stand up and say enough's enough - and peaceful civil disobedience has always been a part of the movements that have got us the social progress that we've got today.

"We think it's important, and we stand by it and we are really proud of our 12 activists.''

A police spokeswoman confirmed the arrests had been made, the protesters had been taken to Timaru Police Station, adding charges were likely. No further details were available.

The owner of the station, Murray Valentine, of Dunedin, did not want to comment in detail yesterday on a process that had begun in 2005, but said he would be "very happy'' to speak with the Otago Daily Times at a later date.

"It's a big development, but we're just a small family farm,'' he said.

"We accept that people have their own views: some people oppose us and some people support us.''

He said while it was not needed, he had prepared food for the protesters. He also organised a portable toilet for them.

Yesterday's action had caused "a whole lot of disruption for everybody''.


"Some vehicles have been broken into, some people being unhelpful, but basically, the same delay that we would have had if we had a day of rain.''

Construction would continue, Mr Valentine said.

A Greenpeace petition that uses the farm to highlight its drive to stop new dairy conversions had nearly 31,000 signatures last night.

Federated Farmers High Country chairman Simon Williamson called the protesters "irresponsible'' and said the area needed "balance''.

He called the current situation in the Mackenzie Basin "complex''.

The ground had degraded and the tussock-covered land that many who signed the petition might have been trying to protect was no longer there.

"That's long gone with hieracium, and rabbits, and now you've got pine trees incursions on it - there's so many issues on it that these people just don't understand,'' he said.

"The water is pristine up here and they will be bound by the same checks as everyone else, and if there is found to be a problem, they will be held accountable.''