Lake Tekapo not feasible as source of irrigation

More than $90,000 has been spent on a study showing that taking water from Lake Tekapo for irrigation would be too expensive to be viable.

The 150-page report, released by Environment Canterbury yesterday, examined the economics of transferring water for irrigation from Lake Tekapo, via Burkes Pass to farmland nearer the coast.

The report examined two concepts: a two-cumec (cubic metre per second) year-round transfer to support 11,550 hectares of irrigated land and a 10-cumec seasonal transfer for 25,000ha of irrigated land.

Both proved to be financially unviable, with the second proposal potentially costing between $478 million and $691m to build, with a negative cost-benefit of $1857 per hectare on the scheme.

ECan deputy commissioner David Caygill said the report only examined economic factors.

"In other words, it's only looking at the upfront costs of building the scheme and potential net benefit, not other aspects such as the environmental effects of intensification. But the cost-benefit of any scheme is always the first hurdle, so it's a useful starting point."

Caygill said the report was not the "final word".

"The report takes into account the more than 100 years of previous work on the potential transfer of water from Lake Tekapo . . .

"If an idea has been talked about for more than a century, one report is not going to put it to bed. I'm sure there will be an interesting discussion of alternate options [as a result of this document]," Caygill said.

The report estimated Waitaki power stations could lose up to 50 megawatt hours of generation capability per year.

Caygill said the Canterbury water management strategy allowed for large-scale irrigation projects, such as Hunter Downs, which proposes to irrigate 40,000ha north of the Waitaki River.

However, he said the schemes had to "bring not only economic benefits but also assist in improving the environment by bringing water to degraded catchments".

Green Party MP Eugenie Sage questioned the report's purpose.

"It doesn't even examine the environmental concerns, and they've spent a lot of money on what has already been known. Surely, it's time to put the Tekapo proposal out to pasture."

The report is at

The Timaru Herald