Diesel has spilled into the Waikato River for the third time in as many months and authorities are appealing for help from the public to find where it came from.
Yesterday afternoon several hundred litres entered the river through the stormwater system, which discharges into the river near the St Andrews Golf Course.
The Waikato Regional Council's response team tried to contain the spill, but could not deploy absorbent booms because of the high water levels and so the diesel was swept downstream.
The council has warned people who take water from the river for stock to take precautions to ensure the water is not tainted.
Compliance and education manager Rob Dragten said yesterday's river levels would help to dilute the spill and would therefore minimise any potential environmental damage that it might have caused.