At the end of last year, South Canterbury rich-lister Gary Rooney's offer to buy "dry shares" saved the project from being scrapped then.
In April, Finance Minister Grant Robertson announced Crown Irrigation Investments Ltd's $70million term debt funding would no longer be available to the scheme. So the company released a new funding proposal in August, asking all prospective investors to reconfirm their commitment.
Not enough did.
Chairman Andrew Fraser said yesterday "a significant drop-off in support" meant the scheme could not proceed.
It was not all about intensifying land use and converting to dairying, but rather relieving pressure on existing water takes, decreasing reliance on surface water extractions, and using the plentiful Waitaki River resource, he said.
The company would try to secure the water consent by working with Meridian Energy, which had helped gain it more than 10 years ago.
"We will utilise the consent to protect and enhance our natural environment, including the augmentation of Lake Wainono."
Irrigation New Zealand chief executive Andrew Curtis said the scheme, which had received more than $4million in investment, could have boosted the Waimate economy, created jobs, improved standards of living, and helped resolve water quality problems.
Forest and Bird New Zealand Canterbury-West Coast regional manager Nicky Snoyink said abandoning the scheme was an "awesome" decision.
"Congratulations to the South Canterbury farmers.
"It's a win for the Wainono Lagoon and the Lower Waitaki in general.
"It's liberated future generations from the burden of the debt. They will be free to farm more to natural conditions."
Augmentation of poor-quality water bodies like the Wainono Lagoon was unproven and Forest and Bird would want to see evidence before supporting it, Ms Snoyink said.