The flood threat to the Waitaki River, swelled by three days of heavy rain, has eased but holiday-makers in the Waitaki Lakes and at Lake Pukaki are still being warned of rising water levels as spilling starts from hydro lakes.
Energy company Meridian began spilling water from Lake Pukaki late on Wednesday night.
Meridian spokeswoman Michelle Brooker said a gradual spill would take place for ''a good few weeks'', and spills at Lakes Ohau and Benmore might also be needed.
''We have received over 500mm in the headwaters of the Waitaki in the last two days, increasing levels in Lake Pukaki to 532.88m.
''The increase in water levels, due to the weather event and low electricity demand during the holiday period, means we are monitoring our lake levels carefully and may need to eventually also spill from Lakes Ohau and Benmore.''
Ms Brooker said two teams of Meridian staff travelled the banks of Lake Pukaki and the Ohau River to warn campers to retreat from the shore.
''The Ohau River is high anyway, because of rain at the moment. Obviously water rises, so there is a possibility it might overflow on to the banks. And I think there is some more rain forecast as well.''
Although heavy rain on Monday and Tuesday resulted in the Rangitata River hitting flood levels on Wednesday evening, Environment Canterbury (ECan) duty flood controller Tony Henderson said the Lower Waitaki River was not expected to flood.
Mr Henderson said the hydro lakes had absorbed much of the rain, but were at a stage where they were very full.
''From what I can gather if they [Meridian] do have to discharge from Lake Benmore it won't be at flood levels. It will certainly be higher than the normal flow, but not at flood levels.''
However, he said the Rangitata, which normally ran at just under 100cumecs during the summer, peaked at 2000cumecs about 6pm on Wednesday.
It had fallen to 1400cumecs yesterday, and was dropping steadily, but it would take three to four days to return to normal, he said.
''People just need to be careful because water levels are high and the river will be dirty.
He said campers, hikers and recreational anglers needed to be mindful of the possibility of rising water levels in the Pukaki and Ohau Rivers, as well as all catchment areas above Lake Waitaki and down the Waitaki River.
Police in Otematata said they had already moved campers at Fisherman's Bend on Lake Aviemore to higher ground prior to the Pukaki spill.
