A Northland freshwater campaigner says cattle are still fouling rivers throughout the region - despite the efforts of Fonterra and local councils to get them to clean up.
Millan Ruka, from Environmental River Patrol, said many beef farmers and dairy cattle breeders were simply ignoring requests to fence off waterways.
He said many dairy farmers had fenced off streams because Fonterra would not pick up their milk if they did not do it, but cattle and dry-stock farmers were not under the same compulsion.
He said a glaring example was the herds of unfenced cattle that fouled the Hatea River above the Whangarei Falls, a popular tourist attraction.
"We've got farmers (upstream) refusing to fence, " he said.
"They've got dairy breeding cattle in these streams, and Fonterra whom I speak with every three or four weeks have admitted they can't do anything with those particular farmers. "
The pools above and below the falls attracted hordes of local children every summer - despite an official sign that said the water was unfit for swimming.
Mr Ruka had been patrolling rivers around Whangarei for three years - filming cattle in the water - and reporting the pollution to the Northland Regional Council.
Mr Ruka said the Regional Council could and should use the Resource Management Act to force the offenders to clean up their act.
But council chair Bill Shepherd - himself a farmer - said the council could not do that.
"People out there in the community have different perceptions about what the law means. "
He said the Regional Council had to be very careful how it administered the RMA .
"We can't take liberties with the law, I guess is really what I'm saying."
Mr Shepherd said cattle farmers around the country would go broke if they had to fence waterways on their large spreads, and the council preferred the carrot to the stick approach.
The council put $750,000 a year into a fund that gave farmers a 50 percent subsidy to fence off waterways and many farmers had taken up that offer, he said.
Bill Guest of the Northland-based lobby group, Farmers of New Zealand, scoffed at the idea that Northland farmers could not afford to keep cattle out of rivers.
"If you can't afford to go and buy a coil of wire; if you had six coils of wire, for a thousand bucks, you can do a hell of a lot of fencing.
"And with one electric wire - talk to the electric fencing guys, one electric wire will stop an elephant."
Whangarei mayor Sheryl Mai said it was disappointing that some farmers were thumbing their noses at the community's wish for clean water.
She said the District Council had spent $60 million in recent years, to expand the sewerage system, because people wanted an end to sewage spills in Whangarei Harbour.
"I campaigned on being able to swim at the Whangarei Town Basin," she said.
"That is something that is a very high priority, getting that water cleaner than it is."
Ms Mai said young people would swim at Whangarei Falls, whether the warning sign wad there or not.
"The identified major polluter is the cattle.
"To keep the cattle out of the water requires fencing and that's not being done."