Wind farm knowledge expanded

For the first time in New Zealand, the results of a long-term avian monitoring programme at an operating wind farm have been published: the results substantiating our ecologist’s predictions about how the working turbines would affect birdlife at the site.

Our ecology team provided freshwater and terrestrial ecological services on Meridian Energy’s 62-turbine West Wind Farm for ten years over every phase of the project, including the initial scoping and design-stage assessment of effects in 2003; the presentation of expert evidence at the Environment Court in 2005; further ecological advice and monitoring in 2005/06 prior to construction; and latterly, post-construction monitoring from2009 to 2012.

Developing a methodology

“The assessment of wind farm effects on birdlife was particularlychallenging because, back in 2004, there was no data specific to New Zealand avifauna,” recalls ecologist Stephen Fuller. “So, we combined what we knew from international studies. with our knowledge of the habitat utilisation and behaviour of New Zealand birds, and made the best judgements we could about the risk for each species.”

The Environment Court accepted those conclusions, but stipulated a long-term post-construction monitoring programme as a condition of the resource consent.

“We soon found that the overseas monitoring methodologies, which had been developed in continental situations, didn’t work on our rugged island terrain,” Stephen says. “So, we had to either modify those methodologies or start from scratch and develop our own.”

Methodologies were developed to measure bird abundance and diversity, record mortalities, and investigate carcass removal and searcher detection rates in order to obtain an estimated mortality rate for the wind farm.

Baseline avifauna data was gathered quarterly in the year before construction began, and then compared with the post-construction data which was gathered (fortnightly) over three years and reported annually to the Wellington City Council and Department of Conservation. The post-construction results mirrored the pre-consent predictions, both in terms of the species and levels of mortality experienced. “It was what we expected to see,” says Dr Leigh Bull, specialist avifauna ecologist. “It was also pleasing to note that we were able to positively influence the wind farm design early on.

The results endorsed the removal of four proposed turbines from around Makara Estuary; the only local pied shag habitat.” In developing the methodology, Stephen recalls being very aware of the considerable field time such a large multi-year project would require.

“Consequently, a key focus was to gather enough data to answer the key questions. For this site we believe we got the balance right”.

“We would like to thank Meridian Energy for allowing us firstly to test and develop our methodology on what was a very important site for them, and then allow us to make the study public via conferences and publication.”

For further information please contact Stephen Fuller or Dr Leigh Bull

3 April 2013