Silver lining to the rain clouds

Rain pouring down in Southland is helping to recharge aquifer levels.

Environment Southland water resources scientist Steven Leddington said the persistent rainfall had helped recharge all but one of the perilously low aquifers.

The Riversdale aquifer has been restored to November levels, helped by 52mm of rain falling during the past 11 days.

Soil moisture had been high enough to penetrate through to the aquifer and had risen 10cm since Christmas, a significant volume of water across its area, he said.

"The rainfall has taken some of the heat out of the situation and, although we're not out of the woods yet, it's a good sign."

It is the same story at the Five Rivers and Waipounamu aquifers, which have also made up ground with high volumes of rain falling just this year.

Both had returned to levels recorded late last year and were still climbing, Mr Leddington said.

The Edendale aquifer was the only one to show no sign of recharge and was still quite low, he said.

Because it was a terrace aquifer, soil moisture would have to reach capacity before water would filter through, Mr Leddington said.

The Edendale aquifer was more inclined to change seasonally rather than be affected by weather events, he said.

There were still a couple of months before the aquifers could reach the safety of the winter months but the rain was a welcome boost, Mr Leddington said.

High rainfall also meant the council was put on high alert because of rising river levels.

Scientific officer Chris Jenkins said flood alerts were in place for 12 hours from 6am on Sunday, but were a precautionary measure and had since been lifted.

River levels are unusually high for January, particularly around coastal areas, with the Waihopai, Makarewa and Mokoreta rivers the worst affected.

Rainfall since the beginning of January had been "very high", with levels ranging from 52mm at Riversdale to 123mm at Mt Hamilton, Mr Jenkins said.

Typical levels for this time of year were about 30mm.

Invercargill's total of 107mm had been boosted by an intense rainfall of 16mm during half an hour last Thursday, he said.

- © Fairfax NZ News

Newest First

Oldest First