People have been advised not to swim in rivers, streams or harbour areas for the next couple of days in case recreational waters were contaminated following heavy rainfall.
Toi Te Ora Public Health has issued a public health warning advising people to be careful swimming in recreational water due to potential health risks.
Chief medical officer of health Dr Phil Shoemack said water was likely to be contaminated with animal faeces from rural and urban run-off after last week's heavy rainfall.
"As a precaution people should avoid swimming in rivers, streams and harbour areas for 48 hours after heavy rainfall events," he said.
"If you swim in or drink contaminated water, you risk getting sick...Illnesses you can catch include a tummy bug, a sore throat or skin infection."