Reducing the use of a controversial pesticide in Christchurch could cost ratepayers nearly $90 million between now and 2025.
The Christchurch City Council is considering whether to limit the use of glyphosate to sites closed to the public.
The chemical has been found to be probably carcinogenic by the International Agency for Research on Cancer.
The council will decide tomorrow whether to go ahead with a plan to reduce the use of the toxic chemical.
Using alternative methods to kill off weeds would cost ratepayers an average of 5.85 million dollars every year for the next three years, and 4.97 million dollars every year after that.
If the council agree, the proposal will still be subject to public consultation.