The controversial Waimea Community Dam will proceed.
Tasman District Council voted 9-5 in favour of the project.
The decision comes at a critical time for the council and private investors, with the offer of Government loans and funding expiring on December 15.
The Tasman District Council’s Local Bill, which would secure the remaining land required for the dam, passed its second reading this week.
The controversial project, now estimated to cost $105.8 million, was voted down in August, but resurrected a week later when a revised funding model was put to the council.
Both supporters and opponents of the dam addressed councillors ahead of their decision today.
Many of the speakers opposed to the project said they weren’t "anti-dam" but were against its financial model and its impact on ratepayers.
Prominent supporter, Nelson MP Nick Smith, argued that a "no dam" decision would be a "tragedy", given the scale of external funding committed to the project.
Tasman Mayor Richard Kempthorne said in a statement after the vote that the project will deliver a secure source of water for the community for the next 100 years.
"It will greatly improve the health of the Waimea River, which can’t sustain the demands we’re making of it at the moment," he said.
Construction of the concrete rock-faced wall dam in the upper Lee Valley is due to begin in early 2019 and will be managed by the Council-Controlled Organisation set up to run the project, Waimea Water Ltd. Waimea Water is a joint venture between Tasman District Council and Waimea Irrigators Limited.
The council says the dam is the only option that solves all the water-supply challenges facing the council and community in one piece of infrastructure - urban water supply needs, horticultural water supply needs and declining river health with associated environmental, cultural and recreational impacts.
The council says for that reason it is the only option that attracts a significant amount of co-funding from other sources. That's $64 in direct funding and $18.7 million in concessional loans from irrigators, the Government and Nelson City Council.