Otago due for a flood, says hydrologist

Rain in Coastal Otago during the past week has boosted river and soil moisture levels to the point a major downpour could lead to a flood, but that might not be a bad thing, hydrologist Dave Stewart says.

It had been several years since a flood provided a natural clean-out for the region's rivers and they would be much healthier for one, he said.

"We're due for one of those. A burst of heavy rain could just [lead to a] flood as everything is wet."

In the past week, Balclutha has had 40mm, Mosgiel 70mm, Dunedin 30mm at Musselburgh and 90mm at Sullivans dam and North Otago 30mm-40mm.

Many inland areas had received little rain, with most of Central Otago receiving up to 30mm and Middlemarch and Ranfurly 5mm and 8mm, respectively.

More rain was expected this week, which would again boost soil moistures, putting them at a good level to go into spring, he said.

All that was needed was some sunshine, although there was still another month of winter to go.

While not a lot of rain had fallen in the lake catchments, there had been enough run-off in recent weeks to use for power generation so lake levels had not dropped any further, Mr Stewart said.

"We're close to the same level of storage that we had this time last year."

MetService, which has a severe weather warning out for the North Island today and tomorrow, was predicting, in Otago, that the coastal drizzle would continue for the next couple of days with strong easterly winds and driving rain arriving on Thursday as the low moved south.

 

Add a Comment