The liquefaction that has affected several Christchurch suburbs following last weekend's magnitude-7.1 earthquake has also affected aquifers in rural areas.
Irrigation New Zealand chairman, Graeme Sutton, says most bores and pumps survived the quake relatively unscathed, although some are affected by silt and sand, while others have collapsed.
He says on the plus side, well water levels in most areas have risen - many by several metres - although no one knows if the changes will be permanent.
Mr Sutton says there are also new artesian flows in places where they did not previously exist.
