Longbush Kindergarten was forced to close this week after mud and sediment from winter grazing runoff washed through the kindergarten's grounds.

Environment Southland chief executive Rob Phillips said the council's compliance team was called to an incident where winter grazing runoff from an adjoining paddock affected the kindergarten, forcing it to close.

A clean-up had been undertaken, he said, and there was no evidence of waterway contamination.

Environment Southland was working with the kindergarten and the farm manager to resolve the situation and a full investigation was underway.

Mr Phillips said an abatement notice had been issued to ensure the farmer stopped the runoff going onto the property immediately.

"I continue to be concerned at some of the intensive winter grazing practice in Southland, particularly as farmers now deal with the recent wet weather," he said.

"Farmers need to understand that they must use good management practice for all winter grazing, including using portable water troughs and back fences to prevent cows going back into already grazed areas, as well as carefully managing critical source areas."

He said it was "simply unacceptable" for runoff to have an impact on neighbours or waterways and it was the farmer's responsibility to ensure this does not happen.

"It is clear some farmers need to step up and improve their practice, and those who are demonstrating good practice, need to support and encourage their peers to do the same."

Environment Southland's compliance team is currently carrying out aerial monitoring and on-the-ground inspections of grazing properties.