The quality of some Christchurch waterways improves for the first time in years.
It is under pressure from urbanization, rainwater pollution and waterfowl.
Christchurch City Council Inland waterways ecologist Belinda Margetts said that the five largest waterways generally have reasonable or poor water quality.
But she said the Avon and Styx Rivers had seen a recent improvement.
Ms. Margetts said that the work was done to encourage residents and businesses to avoid pollutants being brought into rainwater, along with more riverbanking
"There are some improvements we see, but there's certainly More work that we can do to improve the waterways and make them better, unfortunately it takes time, involving not only municipal councils or regional councils, but also individual people and communities. "
Belinda Margetts said that if people wanted to that the water quality continued to improve, they had to take into account what they drains in the ir.