Heavy rain is expected for parts of the South Island in the next couple of days, MetService forecasts.
MetService has issued a severe weather warning for Westland and Fiordland and put the Tasman District on a severe weather watch as a low-pressure system moves across the South Island tomorrowand Friday.
MetService Weather Ambassador Bob McDavitt said current projections suggest the system will weaken as it approaches the South Island.
"This should mean less rain accompanying the system compared to recent events," he said.
"There may still be sufficient amounts of rain reaching the Clutha catchment during Thursday so that people near the already high Southern Lakes and rivers should keep a close watch for further rises in water levels."
As this low moves away on Friday, a cool southerly wind change is expected to spread across the eastern South Island and reach Cook Strait by nightfall.
The Otago Regional Council has advised farmers to move stock to higher ground and said campers should also be aware of rapidly rising lake and river levels.
Council flood manager Phillip Purves said further rainfall was predicted for the Clutha catchment, with the MetService predicting up to 100mm of rain at the divide, and 25-50mm over the rest of the catchment tomorrow.
Both lakes Wanaka and Wakatipu were already high and the predicted rainfall meant both lakes would peak on Friday morning, he said.
However, overflowing lake levels should cause only minor flooding of low-lying areas, and the Otago Regional Council said no ``significant'' problems were expected.
High flows were expected in the Kawarau, Upper Clutha, Lower Clutha rivers.
