In Ashburton, river levels have been falling but it could take two or three more days to drain and people need to keep their bags packed in case stopbanks burst, Ashburton District Mayor Neil Brown says.
As heavy rain continued today, half of Ashburton's residents had been preparing to leave their homes.
Officials had been meeting this morning in response to the flooding disaster that has hit Canterbury since the weekend due to heavy rainfall.
In the latest update on flooding in the region, Brown spoke alongside council chief executive Hamish Riach.
He said while it had stopped raining the river was still full and there was still pressure on some spots.
Residents were still required to have a bag packed and be prepared to evacuate, he said. It could be another two or three days before the catchment dropped back to normal levels.
Riach said it may feel like it's "just a rainy day" but the pressure on the rural area was high with a lot of surface flooding. There were other issues including floodwaters getting into the wastewater system.
Four bridges were gone, and there were numerous roads where the seal had been lifted off the road, Brown said.
Seventeen roads were closed, including the Gorge Bridge and Rakaia Bridge - the roads to Christchurch.
Residents should avoid any unnecessary travel and remain at home, Brown said.
"There is a lot of damage, a lot of water has been swirling around, creating holes in the road, and if there's water still in them, you won't see them and your car will just drop into them."