Low flows lead to restrictions

PARCHED: The Waiohine River as seen on Saturday from a scenic flight. Water take restrictions are in now in force, although the Waiohine River is not yet restricted.

Water take restrictions are in force for all but three Wairarapa rivers as increasingly parched conditions cut flows throughout the region, Greater Wellington Regional Council resource officers say.

Wairarapa resource adviser Sue Silvey said there were two levels of restrictions governing takes from Wairarapa rivers and ground water - either nights only or stock watering only - and there were no full cut-offs yet in force.

The Kopuaranga, Waiohine and Taueru rivers had so far escaped restrictions as well, she said, "but they are close".

Restrictions on ground water were in place in Martinborough, the lower end of the valley and at Te Ore Ore, Ms Silvey said, although enforcement depended on the location and depth of the bores or aquifers in the wider region.

Hydrologist and senior analyst Mike Gordon said rainfall had been intermittent but usual through most of December "and wasn't really summery at all then somewhere around Christmas, somebody turned the tap off and it really hasn't rained since then".

"We've had one period around New Year but not a particularly heavy fall," he said.

"We're getting down to annual low flows down in Martinborough and close to that elsewhere and if it carries on like this, the restrictions will mean some will have to stop using irrigators and as it gets lower, others will have to stop taking water altogether.

"Most rivers coming out of the Tararuas are nearing seasonal low flows and we have various trigger levels, both at our monitoring sites and in some smaller streams in which the flows have to be measured to work out the restrictions."

He said the Waiohine and the Waingawa were low enough to warrant restrictions soon and the Waihenga was quickly approaching a one in two year low, but not as dry as the 2013 summer.

He said the lack of a southerly weather system and the dry northwesterly winds were expected to continue affecting water flows "but there isn't anything too drastic - it's just turning into a typical Wairarapa summer".

The South Wairarapa District Council on Friday posted a warning about low flow in the Tauherenikau River and a consequent reduction inflow in the Longwood water race.

"Our resource consent requires that the Longwood water race flow be reduced. This means the outer reaches of the Longwood network may not have a consistent supply of water. Please make sure other arrangements are in place for watering of stock."