Otago Regional Council environmental information and science director John Threlfall said the council expected the Clutha River to reach 2000cumecs at Balclutha early today as it absorbed heavy rainfall in its headwaters.
The headwaters of the Dart River received 54mm of rain at the weekend, the Shotover River 29mm and in the high country west of Lake Wanaka, at Albertburn, 109mm of rain fell.
In the 24 hours to 3pm yesterday, Queenstown had 29mm of rain and Wanaka 22mm.
Mr Threlfall expected the Clutha's levels to rise overnight "but there shouldn't be too many problems".
Lake levels were high but had not reached warning levels.
More rain was forecast this week but it was not expected to cause problems because rivers were expected to have dropped by Tuesday or Wednesday.
Heavy showers around the Wakatipu basin caused havoc in and around Queenstown on Saturday as rocks fell on roads and creeks and culverts overflowed.
Constable Phill Hamlin, of Queenstown, said one vehicle "aqua-planed" on surface flooding on the Glenorchy-Queenstown Rd.
The driver, a man in his 50s, was treated for minor injuries after his car slid off the road and into a tree.
An oil spill had to be cleared from State Highway 6 near the Devil's Staircase when a car was damaged by a falling rock, Const Hamlin said.
The level of Lake Wakatipu rose from about 309m to 310.5m at the weekend but remained about 30cm below the first warning mark.
Yesterday, Lake Wanaka was at 278.3m and Lake Hawea at 346.25m - higher than before the weekend but still well below first warning levels.
Central Otago escaped lightly after heavy rain fell on Saturday night in Alexandra and Cromwell, before becoming fine yesterday.
In the Maniototo, about 8mm of rain was welcomed by most.
Oamaru had 1.2mm of rain on Saturday and Sunday, with small amounts falling inland - 2mm at Stoneburn and 3.5mm at Dansey Pass.
Contrary to weather forecasts, parts of South Otago enjoyed balmy May temperatures of close to 20degC on Saturday.
