Heavy rainfall swelled Lakes Wakatipu and Wanaka over Queen's Birthday Weekend and the risk of flooding is not over, as water from sodden catchments fills lakes and rivers this week.
Otago Regional Council duty flood manager Mike Goldsmith, of Dunedin, said yesterday river levels had peaked after the deluge, but water was still flowing into the lakes, albeit at a slower rate.
Lake Wakatipu rose by 80cm over the weekend and was at 310.4m above mean sea level yesterday. Flooding worries start when water rises 310.8m above sea level.
Lake Wanaka was also higher than before the weekend, rising 1.3m to reach 278.08m above mean sea level yesterday afternoon. The risk of flooding in Wanaka began at 279.4m above mean sea level.
''The duty flood manager is watching these things all the time, but obviously when you get an event like we had over the weekend, we take a lot more interest,'' Mr Goldsmith said.
''The lakes were quite low prior to the weekend, so if we were to have that same amount of rise again, then we would be starting to look at some serious problems. That's why the risk of flooding is much higher now than it was prior to the weekend.''
The volume of rain was not abnormal. What made the difference was fresh snow on peaks which melted before the downpour, resulting in a greater intake of water than normal.
The forecast included rain, but not on the same scale as at the weekend, he said.
• In the lower reaches of the Clutha River, the river had risen past its first flood warning level of 1140cumecs at Balclutha last night. It peaked at more than 1500cumecs yesterday before starting to drop and was at 1306cumecs at 7pm.
