Greenpeace has erected anti-Ruataniwha dam billboards around Hawke's Bay this week in a bid to "send the message that these elections are really important".

But Hawke's Bay Regional Council chairman Fenton Wilson says they are just another example of the confusion around the water storage scheme and its impact on the region's future agricultural landscape.

Between Central Hawke's Bay and Wairoa, about 10 of the large billboards titled "Dam Wrong #stop Ruataniwha", and featuring an image of a cow with its tail replaced by a tap, were installed over the last few of days.

Greenpeace sustainable agriculture campaigner Genevieve Toop said after next month's election a new council would be an important deciding factor on whether the dam went ahead.


"Water will be front of mind for many voters," she said.

"We wanted to make a clear link between the dam, intensified dairying and water pollution and send the message that these elections are really important.

"After what's happened in Havelock North, the new council needs to put people's health before more industrial dairying and drop the dam.

"Local waterways in Hawke's Bay are already polluted and under pressure. The Ruataniwha dam will compound these problems by driving more intensive dairy farming."

Greenpeace's message was predicated on the regional council-commissioned MacFarlane report that predicted 35 per cent of the irrigated area would be used for dairy farming.

This conflicted with Irrigation New Zealand's message that was recently detailed in a full page advertisement run in local papers.

It claimed that out of the 190 farmers signed up to the scheme there were no new dairy conversions, and only one irrigator planned to expand an existing dairy operation by 100ha.

Mr Wilson said throughout the process it had been hard for the community to decide what information was accurate and what was not, especially when unchallenged claims were repeated.


The bottom line for him was to look back into the past and what had happened over the years, he said.

"Back in the day the Heretaunga plains were awash with dairy farms. Irrigation came, and the land use started changing.

"My father-in-law irrigated 200 hectares of lucerne which he would supply the racing industry, and that land is now in vineyards and other tree crops - there's no dairy farms any more."

Such a cycle could conceivably be replayed on the Ruataniwha plains with irrigation from the dam on the rich, fertile soil in the footprint, he said.

"As water security becomes more certain, growing food will become more lucrative, and early dairy will be pushed out to the rolling hill country ... it will make more sense and make more money to put the opportunity into food for human consumption.

"The economy will have its own regulation on land use - the certainty of water will make it far too valuable to put through rumen to make milk."