Four years of study and more than 40 reports have found a proposed $230 million irrigation scheme in Hawke's Bay to be technically, environmentally and financially feasible.

Now all that is needed is willing investors and a resource consent.

Hawke's Bay Regional Council received the Ruataniwha Water Storage Project feasibility report yesterday on the 85-metre-high dam proposed west of Waipawa.

It would provide water to up to 25,000 hectares of drought-prone farmland and result in more intensive dairy, arable and sheep and beef farming.

Although this would increase the amount of nitrogen and phosphorous entering the Tukituki River, reports show this would have "relatively minor effects" on the eco system as long as proposed mitigation works worth $7.4m were undertaken.

This included planting alongside waterways that would be funded by those paying for water.

Head of BNZ Advisory Duncan Southwell told the council meeting that the scheme's capital and financing structure would be in public and private ownership for the first 10 to 15 years.

As more investors came on board, it would become fully privately owned from about year 15 to the end of its resource consent period of 35 years.

It would then transfer back to public ownership.

Mr Southwell said the project was feasible if water was sold for 20 cents to 30c per cubic metre.

This would provide good returns on investment, and at current debt levels, would be able to be fully bank debt-funded.

"If the water distribution price is too high, the project could be a failure due to lack of project uptake.

"Conversely, if the price is too low, all you are doing is transferring the profit to behind the farm gate," he said.

Earlier this year the council provided $80m for an equity stake in the project.

Councillors now have until October 31 to consider the report and decide whether to proceed to the resource consent stage.

If they proceed, the project would be transferred to the Hawke's Bay Regional Investment Company and engagement with potential investors would begin in earnest.

The project was likely to be called in by the Environmental Protection Agency in January with a final decision on whether to proceed probably made late next year.

- © Fairfax NZ News