"This is supposed to be a hundred year project", Mr Belford said, "who gives a damn if it is built this year or the next year if the work has not been done to support it".
Alluding to a September deadline, Mr Belford said the only reason it had to happen then was so "the concrete can be poured before October."
Mr Belford said there was potential the project might not be so favourably viewed after October 8 - polling day for local government elections.
Constituent Robin Gwynn said: "If a group of councillors who represent 40 to 45 per cent of council have to feel the urge to create this meeting...I think the processes within the council have failed."
When Mr Gwynn asked about the geological and earthquake risks associated with the dam, Mr Graham suggested a panel be created to review them.
HBRIC chairman Andy Pearce spoke, saying such a committee had already been formed.
"It's interesting that none of you councillors have asked questions about this", he said.
"Maybe your own due diligence isn't too flash."
Following boo's from the crowd, Mr Belford said the company was setting the council up as they had to be "bright enough to come up with the right question at the right time or you fail, and we're tired of failing."
Seconded by Mr Graham, Mr Belford also said HBRIC should not survive the next election.
A woman in the crowd said she did not understand why people were risking children's future in the region on an "ego competition".
When Councillor Dick was not allowed to respond to her question, he said: "this is a sham and a charade".
A lawyer associated with HBRIC questioned whether the forum process would have been better with opposed-view councillors also involved, giving them a chance to respond to questions.
Mr Graham agreed there had been one-way traffic, but that he "would absolutely welcome that debate".
In response, Mr Dick said: "The stuff you've said tonight is very persuasive and eloquent, but every point can be debated or contested.
"It is a one-way conversation and that is why this meeting tonight is a travesty and a sham."