Westland District Council is to ban aerial application of 1080 poison in water catchments, a decision that worries the Animal Health board.
Westland District mayor Maureen Pugh says the decision made because of concern from the community about the possibility of 1080 contaminating drinking water supplies, despite the fact that there has been no problem with this to date.
She said the ban will apply to 10 water catchments in the area, and would fall between ridge lines, rather than the current method which sets a prescribed distance or buffer zone surrounding the water source.
But Ms Pugh said the council will be working to see whether the zones where 1080 is banned can be reduced.
Maureen Pugh says landowners will not have to bear all the extra costs associated with ground-based possum control, such as trapping and bait stations.
Animal Health Board spokesperson Nick Hancox said the move risks setting back the programme to reduce possum numbers.
He said the West Coast has the highest rates of bovine tuberculosis infection in the country, but the levels had been brought down in recent years due to the large-scale possum control programme which has included aerial poison drops.
Mr Hancox said the Animal Health Board will check whether the council has the legal jurisdiction to ban aerial applications of 1080 around water catchments, because those decisions are usually handled by the Ministry of Health.
Federated Farmers West Coast President Basil Meyer said aerial distribution is the cheapest and easiest way to keep possum numbers down.
He said there may be significant costs associated with ground-based possum control. The alternative would be to spend the same amount of money and reduce the possum control, which he said would be a huge concern to farmers.