Thames Coromandel District Council says a sinkhole has formed near the Onemana Wastewater Treatment Plant.
In a post online the council says it suspects treated wastewater may have entered a local wetland, potentially entering a stream that flows to the beach.
It says the sinkhole is on private property near the wastewater treatment plant’s subsurface irrigation field.
Onemana is a coastal community on the Coromandel Peninsula, north of Whangamata.
“As a proactive step, we are erecting signage by the Onemana Drive Carpark advising people not to swim, fish or collect shellfish in the area around where the stream discharges until further notice,” it said.
The council said it was turning off the irrigation disposal that is closest to the sinkhole, carrying out water sampling and would monitor the site to ensure no further deterioration or land movement.
This article originally appeared on RNZ
