The National Collective of Women's Refuges says its resources are being stretched in Christchurch, with only two of the city's usual five safe-houses operating after the earthquake.
The collective's chief executive, Heather Henare, says domestic violence has doubled since last week's quake and demand on its crisis phone line has risen sharply.
Ms Henare says three of the city's safe houses suffered structural damage, and the national organisation is transferring some families out of Christchurch to relieve the pressure.
Ms Henare says she is worried vulnerable woman will go back to violent partners if they are unable to get the resources they need from other places.
She expects domestic violence to increase in the coming weeks as people return to the city and face a future without jobs and homes.