Regional council staff in Otago are on alert as more heavy rain is forecast for the headwaters of the Southern Lakes.
Rain is expected to lift Lake Wakatipu and Lake Wanaka beyond their already high levels in the next 24 hours from 1pm on Sunday.
River flows in the Upper Clutha catchment are also expected to increase.
The Otago Regional Council says while no flooding is expected in Queenstown, Glenorchy or Wanaka, low-lying areas along the foreshore may be affected.
The council says it is liaising with staff at Queenstown Lakes District Council - and the latter will give owners of premises ample warning if the situation changes.
Floodwaters draining from the lakes are expected to cause high flows downstream in the Clutha River, so farmers and campers are advised to beware of rapidly rising water levels.