Christchurch City Council has again urged residents to limit water use.
Mayor Bob Parker says February's earthquake destroyed almost a third of the city's sewage system and the treatment ponds in Bromley are under considerable pressure, potentially creating public health issue.
He says regardless of where residents live they should not be taking water for granted.
Mr Parker says everyone in Christchurch needs to limit water use and flush the toilet only when necessary - not just people in the most affected parts of the city.
He says residents should use portable toilets if they're available on a street nearby.