Attributable to Otago Regional Council (ORC) Duty Flood Officer Ellyse Gore:

While the exact impact of the deep low approaching the South Island of New Zealand is still uncertain, there is a chance of a significant and widespread weather event that may affect some of Otago’s already high lakes and rivers towards the end of this week. This statement is intended as a precautionary advisory only to inform the community that councils in the area will be adopting a watching brief.

The former Tropical Cyclone UESI, which has been reclassified as a deep low, is being forecast with high confidence by MetService to bring warning amounts of rain to Westland from Sunday, and with moderate confidence to bring warning amounts of rain to the lower South Island, including parts of Otago and the headwaters of the Southern Lakes.

It is unusual for the South Island to be affected by this kind of weather system, and we should have a clearer picture tomorrow of what it will look like when it hits our shores towards the end of the week. There are currently no active warnings or watches for heavy rainfall across Otago.

ORC’s flood management team is monitoring the event closely and will be predicting its potential effects once we have a clearer picture of rainfall in Otago. While the main impact of the former tropical cyclone may be absorbed by Westland, there is also a chance of it wrapping around the lower South Island and dumping more water on the region if the system tracks further southeast.

Otago lakes and rivers have been receding after last week’s rainfall and flooding, but some lakes and rivers are still above normal levels. Lake Wakatipu is currently at 310.7m and Lake Wanaka is at 278m; both lakes are below their official high lake levels.

The Clutha River at Balclutha, which peaked last week at around 3179 cumecs (cubic metres per second), is currently at around 984 cumecs. The Pomahaka and Taieri rivers could also be affected, as well as Dunedin and North Otago.

ORC will issue another update before the weekend.

Up-to-date river and lake monitoring information is available online:

https://www.orc.govt.nz/managing-our-environment/water/water-monitoring-and-alerts