Tasman District Council has approved the $105 million Waimea dam project after a marathon meeting.
Tasman councillors have this afternoon voted nine votes in favour to five against after an almost seven-hour meeting to determine the fate of the Waimea Community Dam.
The decision came after a tense and at times vocal hour-long public forum in the council chamber, that was being monitored by tight security.
Opponents resent supporting a project they say will benefit a few.
However, supporters say the regional economy will be placed at great risk without a secure water supply.
Golden Bay resident Louise Coleman was among opponents concerned that rate payers would bear the burden of spiralling costs.
"Today you choose whether to support democracy or whether to support greed," she told councillors.
A long-time fruit grower Philip Malcolm said it was a fallacy that only a few will benefit.
"It's been often said this is only for the orchardists or the fruitgrowers...water is needed for our town, and the town is growing."
The decision ends almost two decades of planning and increased public opposition over growing costs.
The council said it had cost $15m to reach the stage it's at today.
Councillor Mark Greening spent 20 minutes pleading with the council to step away from the project.
"This should not be [up to] an old boys' club. You need to be able to put the cards down and walk away.
"We have exceeded our limits - you have exceeded the limit you agreed with your community - your community is pleading with you to step away from this table," Mr Greening said.
Councillor Kit Maling said the impact for the region without the dam would be immense.
Deputy Mayor Tim King said it was the council's biggest project at the moment but it faced bigger challenges in future without it.
He said the decision represented a model for the future whereby large-cost projects would require input from private enterprise, government and iwi.
"It is the only way we're going to be able to confront the never-ending list of issues that are going to make this issue.
"Despite the fact that at the moment it is the single-biggest thing we've ever confronted, it will not be the biggest thing we confront in the future."
John Palmer of Waimea Irrigators said reaching a decision has been a tortuous process.
He was not sure which way the council would go today but he was glad it was over.
"I was not confident but I was certainly hopeful and expecting it would get over.
"It's a sufficiently strong vote by the council that it puts it to bed and we just get on with it."
Mayor Richard Kempthorne, who has backed the project since its inception, was also relieved.
"We'll be able to let things settle and just go forward in life without a catastrophe around the corner."
The decision secures government funding for the project through Crown Irrigation Investment Limited, and the Environment Ministry's Fresh Water Improvement fund.
The dam's construction in the Lee Valley is expected to begin next year.