Some houses built on Christchurch's low-lying flood plains may have to be raised by up to one metre as a result of recent earthquakes in the region.
New post-earthquake floor levels have been set for the Avon, Styx and Heathcote river areas, as well as Sumner.
Of the 160,000 properties in the city, about 10,360 will potentially be affected by a 1-in-50-year flood.
That includes an additional 769 houses which have sunk to at-risk levels since the quakes, which began in September 2010.
Depending on how deep the land has sunk, the floor level of a new house may have to be raised between 27 centimetres and 1.2 metres higher than previous levels.
The Christchurch City Council says the specific floor level for each property will be set as part of the building consent.
The council released the updated information on its website on Wednesday afternoon so that residents can see if their property is affected by the new zoning.
