People are being warned not to swim at some Canterbury beaches after very high levels of faecal bacteria were found in the water.
The Sandy Bay and Rapaki areas are considered unsafe for swimming, and fish from those spots should not be eaten.
The District Health Board says there is potential for serious diseases such as hepatitis A or salmonella.
"In most cases the ill-health effects from exposure to contaminated water are minor and short-lived," said Canterbury Medical Officer of Health Alistair Humphrey.
"However, there is the potential for more serious diseases, such as hepatitis A, or salmonella infection."
If you must eat fish from the area, Dr Humphrey says to "remove the gut and liver and wash in clean water before cooking".
More details can be found on the LAWA website.
The warning comes a day after authorities in Auckland reported a "very high risk" of illness at Home Bay, near Herne Bay.
Other beaches with a "high risk" warning in the super city include St Heliers, Point England, Green Bay, Titirangi beach, Milford South, Coxs Bay, Meola Reef and Te Atatu Beach.
And Wellington is dealing with a collapsed wastewater network spewing material into the city's harbour.
