Paul Bailey's election is being touted as shifting the 5-4 majority of the Hawke's Bay Regional Council in favour of the proposed Ruataniwha Water Storage Scheme to now being against.
Widespread concern about the dam is what the new councillor believes united political views to win him a seat.
Receiving about 7700 votes from Napier residents, Mr Bailey - a two-time Green Party candidate - became one of two new councillors elected over the weekend.
Although former council chairman Fenton Wilson has said Mr Bailey's appointment might not shift the majority, the fact he was elected showed people had serious concerns about the dam.
It was not only his anti-dam stance which Mr Bailey felt drew people to vote for him, but the public knowledge of his "green bent" - having been Napier's Green Party candidate for the past two general elections.