Water may be taken from Lake Tekapo and piped to central South Canterbury for dry lowland farms.

A $226 million scheme to pipe water from Lake Tekapo has been proposed to help 17,000ha of "water-starved" farms in central South Canterbury.

The scheme, proposed by Central South Canterbury Water Steering Group would affect parts of Tekapo, Rollesby Downs, Ashwick Flats, Fairlie, Mt Nessing, Albury, Smart Munro/Levels Valley and Cannington.

The proposal is to extract water from the lake about 10km north of the township, or from the Tekapo River below Fork Stream.

Supplied A proposed new $226m irrigation scheme would take water from Lake Tekapo for central South Canterbury.

The latter option would require operation by Genesis Energy including a pump station and a low dam in the river.

One option would be to pipe water into Lake Opuha which would then supplement the scheme and allow additional water from Cannington.

However, this was thought to be inappropriate and was an unlikely option, steering group chair Ryan O'Sullivan said.

The intended irrigation area would comprise 48.3 per cent dairy, 20.8 per cent sheep and beef, 16.6 per cent dairy support and wintering, 10.8 per cent arable and horticulture, and 3.3 per cent deer farms.

The steering group, made up of five farmers and facilitated by the former PrimePort chief executive and current director of Opuha Water Jeremy Boys, recently presented the proposal to Environment Canterbury's Orari, Temuka, Opihi, Pareora (OTOP) zone committee.

The committee is currently preparing its water allocation plan, due in the next 12 - 18 months.

O'Sullivan​, who is also Federated Farmers South Canterbury dairy chairman, said it was likely OTOP's new rules would change the way water was allocated in its catchment meaning some farmers who could previously draw water from small rivers would have reduced access to water and few alternatives.

Boys said the group commissioned BECA Consulting to investigate environmental issues and scheme design.

The OTOP committee was advised the set up cost was equivalent to approximately $13,200 per ha. Additional operational costs are estimated to be $187 per ha per year.

O'Sullivan could not say how many farmers would buy into the scheme. The initial estimates included many contingencies and construction costs which may reduce once engineers were involved, he said.

BECA used previous investigations and similar proposals to do a "high level" review and consider options in light of technological advances.

Funding for the study came from Opuha Water and money "left over" after Aoraki Water Trust conducted a study into a similar scheme about 15 years ago.

O'Sullivan said the newly-proposed scheme would also produce environmental benefits, with more water in the rivers due to reduced reliance on those sources.

Boys said the committee presentation was part of ongoing discuss about the proposal.

"There is a good deal of consultation to do with runanga. We are very aware of the sensitivities that water creates and bringing it from one catchment to another," he said.

Other organisations and interested groups would also be consulted.

ECan counsellor representing South Canterbury Peter Scott said taking water from Tekapo to South Canterbury had been talked about for more than a hundred years.

"They [the Central South Canterbury Water Steering Group] pushed on and commissioned this study and are just socialising that now," Scott said.

"It is on the table and people are getting the opportunity to comment before it goes through a consenting process, if it does get to a consenting process, and there are not many opportunities to do that."

Scott who, prior to becoming an ECan counsellor chaired ECan's committee advising commissioners on infrastructure matters, could not say how long it would take before the water became available for irrigation.

"If you look at what [Opuha Water] went through from the start to when it let water go, it was 27 years," he said.

Channelling water from Rangitata and Waitaki Rivers were other options that could also be considered in OTOP's plans either separate to, or in conjunction with, Tekapo water, Scott said.

Waitaki MP Jacqui​ Dean said any new irrigation scheme with solutions for water should always be welcome.

The steering group would have to climb several hurdles to get the proposal off the ground including whether or not they can get the water and whether it is included in OTOP's water plan.

"Most of all what is needed to get an irrigation scheme off the ground is dedication, passion and buy in," Dean said.

"Good on them, I say."

She said there was Government funding available for feasibility studies when the group was in a position to up-spec its current one, and she encouraged them to avail themselves of that money.

National MP for Rangitata and Associate Minister for Primary Industries Jo Goodhew said she supports any irrigation project that can sustainably bring economic benefits to the region.

"While this project is in its early stages, I am optimistic about its potential for South Canterbury," Goodhew said.

Irrigation New Zealand chief executive Andrew Curtis said he was pleased the group had taken the initiative to get feasibility of the scheme analysed.

While the price was on the upper limits of affordability, it was not unachievable, he said..

Similar analysis needed to be undertaken on feasibility of a Rangitata scheme and the possibility of using both water sources for irrigation, he said.