Experts trying to restore Christchurch's sewerage system have told concerned residents that the level of bacteria in city rivers is no worse now than it was before the earthquakes.
The city council had to discharge raw sewage into the Avon and Heathcote rivers for seven months following the February 2011 earthquake.
At a public meeting held in New Brighton at the weekend, residents were told that despite the earthquake, the health of the rivers is no worse now than it was before the quake, when it was degraded by stormwater.
The meeting comes on the back of warnings from the Canterbury District Health Board for fishers to stay well away from eating anything caught from city rivers.
Professor Brian Jenkins, from Canterbury University's Waterways Centre, says ecologists comparing the bacterial levels of the rivers before and after the earthquake have found the the sewage discharge after the quakes made little difference.
Among the options to clean the water is to return some red zone areas near rivers to wetlands.
