A health warning was issued for popular swimming spots of Christchurch by health authorities.

This warning comes following faecal bacteria’s high levels that have been seen in the Waimakariri River, near the Main North Road bridge.

According to Canterbury medical officer of health Dr Alistair Humphrey, poor water quality took place in the last few days due to rainfall that led to a rise in river's water flow.

There was a damaged pipe that led to raw sewage spill and beaches that people are being advised to stay out of are Avon-Heathcote Estuary, Sumner, Scarborough and South Brighton.

For about 48 hours, rivers and estuaries around Christchurch were at risk due to infrastructure prone to earthquake damage leading to a high risk of contamination.

Humphrey said, "Water quality at affected sites is not considered suitable for recreational uses, including swimming because of the risk to health from the bacteria and other pathogens. Eating fish or shellfish from these sites should also be avoided."

He added that contaminated water caused illnesses that could prove dangerous to many and hence should be avoided.