"Therefore how much water there is at depth, and the feasibility of getting it out, is academic because the evidence we have is it's all connected and it all discharges out of the basin via the Tukituki and Waipawa Rivers," Mr Maxwell said.
"All of this was traversed through the board of inquiry process, including the view that our model was no good.
"The board of inquiry didn't agree with that," he said.
If it goes ahead, the Ruataniwha dam will provide additional water for farmers on the Ruataniwha Plains, where current allocations to take underground water are fully subscribed.
The council has conditionally agreed to invest up to $80 million of ratepayers' money in building the scheme, but it will only go ahead if a number of conditions are met, including that sufficient farmers sign up to 35-year water-take agreements so that the project is financially viable.
Dam meeting tonight
Backers and opponents of the Ruataniwha dam will square off at a public meeting to be held in Napier this evening.
Organised by Hawke's Bay Today, the meeting will include a presentation from Andrew Newman, chief executive of the regional council-owned company promoting the $275 million scheme, Hawke's Bay Regional Investment Company.
Mr Newman's presentation will be followed by a panel discussion, featuring Wellington economist Peter Fraser and Fish & Game environmental manager Corina Jordan who have been invited to participate by Transparent Hawke's Bay which opposes the regional council's plans to invest up to $80 million of ratepayer money into the Ruataniwha scheme.
The meeting is being held at Tamatea Intermediate School, beginning at 6.30pm.
Questions on the scheme will not be taken from the floor but readers are invited to email questions to: editor@hbtoday.co.nz
People will be asked to make a gold coin donation to the Limitless Hope Emergency Shelter Appeal.
