Author: Petra Stock
Assessing potential impacts on flora (plants) and fauna (animals) is an important part of your planning application for a proposed wind farm. Assessment of flora and fauna tends to focus on the removal of native vegetation and the potential impact on threatened species (those protected under state or federal legislation).
In some circumstances the assessment can also address potential impacts to unprotected species such as wedge-tailed eagles or ibis, or areas of non-protected vegetation that may have special significance to locals. These assessments are often subject to seasonal changes and the migration patterns of certain species.
Flora and fauna studies are an important part of the detailed assessment phase because native plants and animals are often fiercely protected by the community. Even a small chance of impact to a native bird, for example, can derail the planning process for a wind farm.
Standard assessment
A standard flora and fauna assessment for a proposed wind farm usually involves:
- a review of state and federal threatened species registers, to establish which flora and fauna could potentially inhabit the wind farm site and surroundings
- a site survey to verify initial research, identify areas of native flora and fauna habitat, and determine the likelihood of identified fauna species inhabiting the site and surroundings
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a 'level one' bird assessment to identify the species most likely to be present on site.
A qualified ecologist, zoologist and/or botanist should carry out this assessment. It needs to cover the footprint of all the wind turbines (and any alternative locations under consideration), and ideally access tracks, substations, and the transmission line route.
The information from this assessment should be enough to submit any referrals under state or federal legislation. This will determine whether a detailed environmental impact assessment is necessary (see individual state planning articles).
Further assessment depends on:
- the outcome of the initial flora and fauna assessment, and an ecological consultant's recommendations
- the proposed wind farm layout and any changes necessary to avoid or minimise impacts
- consultation with relevant local, state and federal authorities.
Local authorities usually require further detailed assessments to consider potential impacts on birds and bats.
Birds
Here is a hierarchy for assessing the impact of a potential wind farm on birds.
Level one
Level One investigations are concerned with bird species on site and usually include a site visit to verify the accuracy of desktop data and habitats present. This information is used to identify potential effects of your wind farm on these species. If Level One investigations are conclusive then this information may be enough for your report. However, if there is insufficient information to conduct a risk assessment, Level Two investigations are undertaken.
Level two
Level Two assessment involves collecting more data on bird species through field surveys. The focus of these studies is finding out which species are present, in what numbers, and how they use the site. Sometimes surveys might involve seasonal comparisons. You can sometimes use the data you collect in a 'collision risk model'. This quantifies the potential for bird collisions with the proposed wind farm infrastructure.
If the data obtained from the more detailed Level Two surveys is insufficient to determine the potential effects of the wind farm proposal, or if there are threatened or priority bird species which require specific information, Level Three investigations will be undertaken;
Level three
Level Three investigation involves more targeted studies to assess a particular season, species or issue.
Unfortunately, it's not always possible to tell whether you'll need a Level Two and a Level Three study at the start of your detailed assessment phase. You'll need to work closely with your consultant and government authorities to establish what flora and fauna studies you need to do.
Bats
The process is similar to the bird assessment in that there are three levels of assessment, each one required if the previous stage proves inconclusive.
You can usually identify bat species on your proposed wind farm site and surroundings using historical records. You can then confirm this with a field survey, using Anabat ultrasonic detectors to record bat calls and identify species. Anabat microphones are installed on wind monitoring towers for several days to record bat species flying at rotor height.
Common planning permit conditions
If your proposed wind farm is granted planning approval, there are often several permit conditions relating to flora and fauna. Two of the most common conditions are:
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If you plan to remove native vegetation, you may need to do a spring survey and/or habitat hectare assessment. This is usually to determine the significance of vegetation being removed and the amount of any offset planting you'll need to do under state legislation.
- A post-construction bird and bat monitoring program lasting two to five years. This involves regular searches for dead birds and bats around the base of each wind turbine (usually to a radius of 60 to 100 m around the wind turbine).
Implications for wind farm layout
Flora considerations in particular can create exclusion zones around your wind farm site. These zones will not only restrict where you can locate turbines and other infrastructure — but also the access paths you use in the construction process. Any potential impacts that construction might have on flora or fauna can be avoided or minimised by the implementation of an environmental management plan during construction.