Auckland Council has approved the aerial use of 1080 in the Hunua Ranges.
The drops will begin in mid-2015 and will cover 1100 hectares, 6.5 per cent of the Ranges.
Helicopters will drop 5kg of pellets per hectare which contain a total of 7.5g of 1080.Councillors Cathy Casey and Mike Lee voted against the decision.The main reasons cited for the drops were to protect native birds such as kokako from stoats, rats and possums.
In 1994 the Kokako Management Area was established with intensive pest control.There are now 55 breeding pairs.Councillor Mike Lee says the management area has been a success and it's something Auckland can be proud of.
"1080 is not as bad as generally thought but it's not as simple either. It's a blunt implement."
Lee had concerns that this is another example of council cutting costs which may have short-term benefits but it will have negative effects in the long-term.
The current pest management plan costs $473,000 a year and includes $75,000 for traps and brodifacoum in bait stations which control stoats and rats.
Possum control is done with cyanide in bait stations.The three year 1080 programme will cost $529,000, taking the three year pest control programme's total cost to $1,419,000.
Rat numbers in managed areas are seven times higher than the target and in unmanaged areas they are 14 times higher.
A report by Mace Ward, manager of parks, sport and recreation says 1080 avoids the spread of kauri dieback disease and the toxins remain in the environment for a short time only.
He says pest levels are extremely high and the current pest management programme is most effective when pest numbers are at low to medium levels.
Councillor Chris Darby says the science shows there are valid reasons it should be used but it needs to be monitored.
"These are nasty chemicals but they are all sometimes necessary. We need to keep monitoring the science. We should not lean back just because we have been given some comfort over its use."
Councillor Bill Cashmore lives on the border of the Ranges and strongly supported the use of 1080.
"When 1080 was dropped in 1994 not one person was harmed and for the first time in years we saw red rata flowers. Now it's rats and stoats."
A 2008 study by the Environmental Risk Management Authority concluded there are no practical alternatives to 1080 for preserving native bush and the protection of agriculture.
Parliamentary commissioner for the environment Dr Jan Wright agrees, saying not only should 1080 continue to be used to protect forests but its use should be increased.
"It is seldom that I come to such a strong conclusion at the end of an investigation. But the possums, rats and stoats that have invaded our country will not leave of their own accord."
Franklin Local Board member Malcolm Bell says the public rumours of 1080 permeate through the discussion but do not necessarily represent the facts.
Bell says he was swayed by the drop being done by helicopter."Helicopters are very advanced now, they have GPS. Pest management around the dams will continue as they are now."