The $250m second stage of the Central Plains Water irrigation scheme in Canterbury has been fully approved by the shareholders.
The whole scheme will irrigate 60,000 hectares of farm land between the Rakaia and Waimakariri Rivers and stage one was turned on a year ago.
Stage two will irrigate 20,000 hectares and cost about $250 million.
Central Plains Water chief executive Derek Crombie said that stage two was slightly different from the original plan.
"We were going to build the scheme in three stages and continue the canal across the Canterbury Plains towards Sheffield. We're now using a buried pipeline and will lay approximately 21km of 2.5 metre to 1.6 metre diameter glass reinforced polymer trunk main pipe linking to a further 184km of HDPE pipes to take the water to the farm gate."
He said 14 pump stations would be built.
"We won't be taking water from the Waimakariri River for stage two, as originally planned, as we now can also source water from Lake Coleridge.
"Very little extra capacity has been built into each pipeline, so it is imperative that those wanting to purchase further shares do so now, otherwise it could be too late."
The CPWL scheme has been developed by about 360 shareholders, who have contributed $90 million.
This was supported by the initial development funding from the Ministry for Primary Industries Irrigation Acceleration Fund, short term loans from the Selwyn District Council and construction funding from CPWL Banks ANZ and Westpac.
Crown Irrigation Investments have also committed to a significant support for the Stage 2 phase of the project.
"The shareholder meeting demonstrated the high level of farmer support and Mayor Kelvin Coe congratulated the group for their vision noting the contribution the scheme and its farms make to the district's economy."
The full CPWL scheme is expected to create more than 1000 new jobs and add more than $1 billion annually to the economy.