Conservation advocates have welcomed a decision by the Auckland Council to drop the poison 1080 in the Hunua Ranges.
A council committee voted yesterday to approve the use of the pesticide in an area that supplies two-thirds of Auckland's water supply.
Experts told the committee a recent explosion in pests is threatening native wildlife, and 1080 is the best way to beat them back.
The Department of Conservation and Forest and Bird both support the decision.
However, Forest and Bird's campaigns and advocacy manager, Kevin Hackwell, says the council could have done a better job of addressing people's concerns about the water supply.
"I think they possibly could have been addressing people's understandable concerns about any poisons we're using in our fresh water catchments for our drinking water, I think they possibly could have done that a bit better."