Half-price Ruataniwha scheme put forward

COLD WATER: Irrigation NZ chief executive Andrew Curtis. PHOTO/FILE

Four Hawke's Bay regional councillors who have spent the past year challenging the Ruataniwha water storage scheme say they want the council to investigate building a half-price alternative.

But their proposal has been labelled naive by an irrigation advocacy group that has been closely monitoring the project.

Councillors Rick Barker, Peter Beaven, Tom Belford and Rex Graham yesterday circulated a two-page document setting out a proposal for what they called "the right dam" to boost the supply of water in Central Hawke's Bay's Tukituki catchment.

"We have consistently endorsed water storage as a prudent strategy for enabling Hawke's Bay to better manage its water to meet the equally important challenges of mitigating impacts of climate change, improving farming productivity, and protecting the environmental integrity of our rivers and aquifers," the paper said.

"We do not believe the dam scheme presently proposed by HBRIC is a defensible response to that challenge, for reasons we have consistently raised, including its pricing of water at 26 cents per cubic metre."

HBRIC (Hawke's Bay Regional Investment Company), the council's investment arm, is working on signing up farmers and growers to take water from the proposed $275 million irrigation scheme, which it hopes to start next year. The scheme involves damming Makaroro River, northeast of Waipawa and Waipukurau, to create a 7km-long reservoir capable of supplying about 100 million cubic metres of water a year to farmers in the catchment.

The four councillors say their proposal would also involve damming the Makaroro but instead of building a water distribution network at a cost of about $135 million - half the price of the scheme - water would be distributed to farmers via existing waterways.

"Farmers more distant from the river on the Ruataniwha Plains could still draw water from the aquifer. Whether from the aquifer or from surface water, such extractions would be compensated by dam water released back into the river," their paper says. It proposes water from the dam be sold for 10 cents per cubic metre.

Irrigation New Zealand chief executive Andrew Curtis said the alternatives presented by the councillors had all been considered before and their paper was "a little bit naive" because ground water was not available on parts of the Ruataniwha Plains.

"Their theory very much depends on being able to access ground water and the reality is, if they spoke to some of the people down the bottom of the plain, they don't have access to ground water."

The complexities of the catchment's water system meant at least some form of distribution network would need to be built as part of what the councillors were proposing, Mr Curtis said.

"We've said for a while now that there are probably savings to be made once we understand what the [water user] demand profile looks like through better design and a combination use of ground water and surface water but there is no way you're going to be able to dump the distribution system altogether. That's quite naive in their thinking and shows quite a poor understanding of the hydrology of the basin."

The councillors' paper asks for the council to support work into the feasibility of their alternative proposal. Mr Beaven said the four councillors planned to raise their proposal at the next meeting of the council's corporate and strategic committee on November 12.

Regional Council Chairman Fenton Wilson said he had no comment to make on the proposal.