Health officials in Canterbury have warned people to avoid beaches, rivers and floodwaters for two days.
Canterbury Medical Officer of Health Dr Matthew Reid says the recent heavy rain has resulted in added pressure on sewerage systems and overflows into many waterways.
"Floodwaters may have been contaminated with sewage and the most important thing to remember when cleaning up is to practise basic hand hygiene," Reid says.
"Always wash your hands using soap after being in contact with contaminated water, and after cleaning up areas affected by flooding.
