A faecal matter: Christchurch rivers polluted by dog faeces, dissolved copper, zinc

Photo / Geoff Sloan

Nearly half of Christchurch's waterways are in a poor condition according to a new report.

Bird and dog faeces, dissolved copper from car brake pads and zinc from tyres and roofing are just some of the contaminants being washed into the city's waterways.

The Christchurch City Council report found the city's water quality is "not improving or declining over time".

The Ōpāwaho/Heathcote River, which passes a number of industrial areas, still has some of the poorest water quality in Christchurch.

The state of the Huritini-Halswell River also remains poor and more needs to be done to start seeing improvements, the city council's chief waterways ecologist says.

Principal waterways ecologist Dr Belinda Margetts, said regular monitoring of the city's waterways began in 2000.

"We've had a significant amount of development and earthquakes and a whole bunch of different things that have happened over that time and the situation hasn't got worse."

She said the city council and the community must keep striving to improve water quality.

But Margetts said Christchurch is unique because it is on swamp and wetlands so has more waterways than most other New Zealand centres.