An early warning evacuation system set up in the Timaru district settlement of Mills Road Huts is being described as a team effort.
The settlement was evacuated three times in the past 10 days because storm surges down the Ōpihi River damaged the stopbank in front of the Huts.
Canterbury Regional Council natural hazards scientist Chris Fauth said the authorities had created an effective system of alarms on three rivers in the area.
"We have early alarms on those three rivers and when we see that they're rising we'll send field staff to the site to observe what's going on there, but we'll also monitor the river and river flows.
"And between those two things we're confident that we can give adequate warning so that they can get those people out within sort of two to three hours notice."
Urgent repairs to the stopbank are continuing.
On 21 July, Timaru District Council declared a state of emergency for the Pleasant Point- Temuka Ward after heavy rains that damaged roads, stop banks and affected the water supply.
This month was reportedly the wettest July in about 70 years for Timaru.