Plans to convert a Mackenzie Basin property into a dairy farm have sparked protests in Dunedin's Octagon.
Close to 100 protesters, some dressed as cows, took a break from work to moo and chant against dairying at Simon's Pass Station.
However, the man at the centre of the controversy, Dunedin accountant Murray Valentine, said the protests were too little, too late.
For protest spokesperson Adam Currie, the Mackenzie Basin was a unique wilderness from his childhood, where he spent his summers camping and winters skiing.
He said he was fighting to allow future generations to have such memories.
"He's going to pump thousands and thousands of (litres of) water into the Mackenzie Basin and will just destroy the wildlife."
There were some areas that should not be converted to dairying, Mr Currie said.
"The Octagon is no place for cows and neither is the Mackenzie."
The rally was organised by Save Our Water Otago/Southland and Greenpeace, but plenty of other groups joined in on the protest.
Forest and Bird's Sue Maturin spoke at the rally, saying large scale irrigation and dairying had no place in the Mackenzie Basin.
"None of us should need to be here today as Mr Valentine should never have been able to develop the land he leases from the Crown."
After speeches, they took to the streets, marching up the hill towards Mr Valentine's office.
The protesters chanted as they climbed several flights of stairs to his office - only to discover it was locked and no one would open the door.
After several tries to find a way in, protesters left a signed letter at his door to urge him to change his plans.
Mr Valentine said he was impressed with the letter but it would not change his plans.
There were plenty of checks and balances to prevent any harm to the environment, he said.
"We get to the stage that we've now got an operational dairy farm... and now you've got people saying, 'Oh, it's time to terminate what you are doing'."
There are already about 800 cows on the property.
In the next decade, he said there would be a maximum of 5000 cows on the property and no more.
Protesters said he was given him permission to have up to 15,000 cows.
He would have been prepared to listen to the protests if it was not about 15 years after he had started development, Mr Valentine said.
Back in the mid-2000s when he first started applying for consents, he said the government supported dairy conversions.