Nothing new in Ruataniwha review - irrigation dam still a bad idea

Monday, May 8: The review of the Ruataniwha irrigation dam confirms Greenpeace New Zealand’s view that the dam will pollute local rivers, heighten the risk of further water contamination and is a huge economic gamble.

Greenpeace spokesperson, Amanda Larsson, says the review of the Ruataniwha dam, released today, has provided no compelling new evidence to support the case for the dam’s construction.

In fact, it confirms that the scheme will contribute to further water pollution - particularly nitrogen - and negative environmental impacts in the region, she says.

“The review offers no solutions to the fact that nitrogen pollution already exceeds water quality limits in the region. It actually concedes that land-use changes driven by access to irrigation could likely result in increased nitrogen loss.

“Nitrogen is a major river killer, and this review confirms what we have seen with irrigation everywhere - it makes nitrogen pollution worse.”

Previous environmental impact analysis by HBRIC Ltd has predicted nitrogen losses within the irrigation consent area would increase by an average of 81%. Even best practice mitigation measures would not reduce nitrogen losses by more than a fraction, according to NIWA modelling.

While proponents of large irrigation schemes continue to argue that irrigation schemes like Ruataniwha can improve the environment through ‘flushing flows’, the review concedes that there is great uncertainty about whether the scheme would provide effective flushing of the Tukituki River.

Larsson says this confirms there is little evidence showing that flushing flows work to improve water quality.

“Evidence actually suggests that dams degrade rivers ecologically and increase waterway and aquifer pollution,” she says.

“Sick rivers mean sick people. We cannot risk a repeat of the Havelock North water crisis, which was the worst of its kind in New Zealand’s recent history.”

“Over two thirds of New Zealand rivers are now too polluted to swim in safely. We should be cleaning up and protecting our rivers, not spending ratepayer money on building giant irrigation schemes that drive more industrial agriculture and compound the problem.”

ENDS

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