"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."