Wind farm no great blow for at-risk bat

This week's Resource Management Act hearing into the proposed Te Uku wind farm has airily spluttered along slowly enough to drive anyone bats.

It was fitting therefore, to hear, during the fifth day of increasingly forensic evidence at Ngaruawahia yesterday, that the greatest ecological risks associated with Wel Network's 28-turbine project might indeed be bat-strike.

Ecology consultant Gerry Kessels told a hearing which has already sucked the life-blood out of all but a couple of die-hards in the public gallery that the wind farm site, between Mt Pirongia and Mt Karioi, was "an almost ideal location" from an ecological perspective.

But he identified the risk of long-tailed bats and possibly the New Zealand falcon as well getting caught up in the massive wind turbines as the key danger.

The long-tailed bat, which lives long but is slow to reproduce, is classified as "nationally vulnerable" but is known to use bush habitat along the edge of Pirongia Forest Park on the eastern side of the wind farm,

The dearth of research on the bats, and the potential effects of wind farms on them, meant Mr Kessels couldn't be too exact in his assessments, even after tramping around the sites in May, June and September using acoustic detection methods to locate the long-tailed bats.

He said it would be at least five years before it could be ascertained whether there was any harm to bats, but was optimistic.

"The risk of significant mortalities occurring is considered to be low, given the site layout, low numbers of bats observed in site surveys and a lack of suitable habitat among the turbines themselves," he said.

All turbines will be "micro-sited" so that they are at least 100m from the bush edge to minimise the risk of bat strike.

Mr Kessels was happy with a series of monitoring and contingency measures proposed to address potential problems.

But commissioner David Hill questioned the point of imposing a strike-monitoring consent condition to deal with an adverse effect after it had already happened.

"If a strike has occurred, what can be done?"

Mr Kessels said it provided a great opportunity for study, given no research had been done on the subject.

"Risks are low but this provides an opportunity to do robust research on bats and wind farms."

On the bird-strike front, Mr Kessels noted that the Brooklyn wind turbine on the outskirts of Wellington lay less than 20m from the Karori Wildlife Sanctuary, and the only known fatality was one blackbird. The turbine has been in use since 1993.

Meanwhile noise generated by the turbines is considered unlikely to disturb forest birds.

Mr Kessels said tui and kereru appeared to adapt to noise associated with roads and urban environments which are likely to be louder than wind turbines. Submitters will have their say on the project on Monday.

- © Fairfax NZ News