The Southland Regional Council has agreed that a dairy farmer can go ahead with a winter grazing trial on his property west of Winton to test whether nutrient loss from the pasture has a negative impact on groundwater.
The council originally gave farmer Jim Cooper permission to do the trial last November.
On Wednesday, the council's environmental management committee reconsidered that decision in the light of preliminary findings by AgResearch scientists that wintering cows on the free-draining land could cause effluent pollution.
The council's compliance manager, Mark Hunter, told the meeting however that it would be unreasonable to ask Mr Cooper not to go ahead with the trial, as he'd already included it in his winter grazing programme.
The trial will measure all the feed the cows receive and then monitor what leaching occurs.