Farmers already dealing with waterlogged paddocks and saturated crops are set to cop more rain this week.
Many farms across Otago and Southland bore the brunt of deluges last week, with damage to crops and flooding across properties.
Forecasters say more rain is expected for the week ahead, with a complex trough of low pressure stretching from the Tasman Sea across much of the country.
The Otago Regional Council says while river flows across the region are generally receding - including the Taieri, Manuherikia and Clutha rivers - some will rise again due to the forecast rain.
It says North Otago rivers have already started rising.
"Rainfall combined with snowmelt and saturated ground may see them reach the high flows that occurred earlier this week," it said.
Council staff are monitoring the 12 Clutha and Taieri drainage scheme pump stations, and says all stations are operating and helping to slowly drain floodwater.
Metservice says heavy rain is on the way for many parts of the country.
"There are currently severe weather warnings in place for heavy rain over Wairarapa and Marlborough, extending well into Monday, and we are watching remaining eastern parts of the South Island closely" said MetService forecaster Cameron Coutts.
However, western areas of the South Island and southwest of the North Island escape with generally fine weather.