The Piako River is at risk of overflowing after the Hauraki Plains has in the last few days been saturated with the same amount of rainfall as fell during recent cyclones.
The Waikato Regional Council is keeping a close eye on the river's water levels, which are higher than normal, and is warning local farmers and duck shooters in the Kopuatai Peat Dome area of the overflow risk.
After Cyclones Debbie and Cook the river over-topped its stopbanks, causing extensive surface flooding. The banks over-topped as designed when the river is in flood.
However, the council says it expects its flood management system to cope with the recent downpours.
Regional hazards team leader Rick Liefting said it was unlikely any overflows would be significant or cause more surface flooding in emergency ponding areas like paddocks this time.