Water restrictions threaten as dry persists

Tasman needs rain in the next week or so to stave off a drought-driven slide into water cuts.

The dry, windy spring has seen groundwater and river levels steadily fall in the last month creating another headache for horticulturalists and water managers alike.

Mark O'Connor, of market gardeners Appleby Fresh, said the dry spring had come off the back of a very wet winter and seen the ground turn rock hard.

The current southwesterly winds stripped moisture from plants and the top layers of the soil.

Irrigation systems were being kept busy as growers prepared their crops for the Christmas markets, he said.

Stage one (20 per cent) irrigation restrictions would not have much effect on most vegetable growers who already struggled to get their irrigation systems around their land and use their full allocation of water, he said.

Grower John Ewers in Appleby said the dry winds were knocking growth around the most.

The dry spell followed persistent winter rains which stopped in September "when the tap turned off".

"If rationing comes in quite heavily now things will be difficult - but here's hoping we get a little bit of rain."

The district council's environment and planning manager, Dennis Bush-King, said the Waimea River's flow was close to the 2.8 cubic metre a second (cumecs) level which triggered consultation with permitted water users.

The council's dry weather taskforce will meet on Tuesday to review the situation across the district.

Mr Bush-King said the Takaka and Motueka rivers were holding up but the Waimea, which was over-allocated and approaching peak demand from horticulturalists, was likely to be the first to reach rationing levels.

The Waimea River was currently flowing at 3.1 cumecs. Consultation with users was triggered when the flow reached 2.8 cumecs and stage one restrictions came into force when the river reached 2.5 cumecs, Mr Bush-King said.

The Motueka River was currently flowing at about 16 cumecs and the Takaka River was holding up, he said.

The few showers forecast for later this week may not be enough to avert water restrictions.

"November has been a starting point for water restrictions previously," he said.

The council's water scientist, Joseph Thomas, said a good dollop of rain was needed on the Waimea Plains before Christmas to see off potential water restrictions.

"We need to be cautious. If we don't get any rain in the next week things can deteriorate rapidly. Even intermittent rain could save our bacon," he said.

"But that is the beauty and the curse of this region. Between November to March we can yo-yo between being close to, or avoiding, drought."

Mr Thomas said the Waimea Plains were particularly sensitive to drought because they had no natural storage.

"When everything peaks this period can be critical for the region in terms of meeting water user needs, keeping out salt-water intrusion and maintaining river habitat."

The National Institute of Water and Atmospheric Research's latest seasonal outlook predicted near or below normal soil moisture, rainfall and river levels for Nelson to January.

The Nelson Mail