Author: Petra Stock
A visual impact assessment is an obligatory part of a development application for any wind farm in Australia. Visual impact is a highly subjective area, influenced by people’s opinion of renewable energy, wind turbines, and how they view and value the existing landscape.
Despite the subjectivity of this type of study, it is guided by a national framework and must be undertaken by experts. This article describes the process as well as what you should expect to find in your visual assessment report.
Assessment guidelines
The Wind Farms and Landscape Values National Assessment Framework (2007) was developed by the Australian Wind Energy Association and Australian Council of National Trusts. The framework was written in order to add some consistency to the subjective area of assigning value to landscape. Wind farm developers and local communities need clarity and certainty when making these assessments. In addition, the framework provides the flexibility to deal differently with areas of high landscape value and those that are considered uncontroversial.
The framework sets out a clear sequence of four steps for dealing with visual assessment, detailed in the framework document linked below. It provides a best practice approach that involves the local community in identifying landscape values, describing the visual effects and designing mitigation measures to address negative visual impacts.
Essentially the steps are:
- Step 1A — Preliminary assessment of landscape
- Step 1B — Full assessment of landscape
- Step 2 — Describe and model the wind farm in the landscape
- Step 3 — Assess the impacts of the wind farm on the landscape values
- Step 4 — Respond to impacts
Step 1A is intended to contribute to your feasibility stage. Steps 1B to 4 consitute the detailed assessment described in this article.
Each step contains the following sections:
- Purpose
- Objectives
- Tasks
- Useful references
- Required outputs
- Reporting to stakeholders
- Questions to consider
- Practise notes
Scoping the job for a consultant
When engaging a consultant to write a visual assessment report it is best to follow the tips and tricks in the article Engaging specialists for environmental & technical studies. Essentially that article suggests writing a detailed scope and getting multiple quotes for the job.
The scope should generally include:
- A detailed description of your wind farm including turbine types or dimensions
- The reason you are having the report written (e.g. to satisfy planning conditions)
- Who will need to read the report (e.g. the planning authority)
- What you expect to see in the report (See "what to expect" below).
It's worth noting that if the turbine model has not yet been selected, estimate the hub height and blade length that will be used. It's best to overestimate these and thus calculate the worst case scenario. If the turbine eventually selected is smaller then the visual assessment report will not usually need to be redone.
What to expect in a visual assessment report
A good consultant report will be a stand-alone document with plenty of description such that it can be interpreted by somebody who is not a professional in the field.
A standard visual assessment usually includes the following topics:
Project description:
- A description of the proposed wind farm site, including proximity to nearby towns, major roads and nearby houses
- A description of the wind farm infrastructure, including the size, colour and materials used in the wind turbines and associated plant equipment
- Any available information on lighting requirements from CASA or other aeronautical authorities
- A summary of the relevant planning policies that apply to the site and surrounding areas
- Zone of visual influence mapping: this shows a map of the surrounding areas from which the wind farm can be seen
- Landscape character analysis — usually a description of the landscape characteristics of the site and its surroundings, including geology, vegetation, topography, and the extent of human modifications and development in the area
Landscape values:
- a description of the existing landscape, identifying significant values associated with the landscape. It's important to get community input for this section.
- A description and map of significant public viewpoints, for example tourist sites, major roads, towns, nearby houses and scenic lookouts. These viewpoints are usually chosen following consultation with local government representatives and the community.
- Photo-montages or other visual modeling tools showing what the wind farm would look like from selected public viewpoints. Photo-montages involve taking a photo from the selected viewpoints, the landscape is then 'modeled' with the proposed turbines depicted to scale (and ideally other supporting infrastructure, such as substations and transmission lines).
- Visual assessments describing the impact of the proposed wind farm on the existing landscape values using the visual modeling tools. Potential impacts are rated as low, medium or high, depending on the significance of existing landscape values, the number of potential viewers, community attitudes towards wind energy, and the degree of existing human modifications in the landscape. It's important to get community input here, too.
- A cumulative impact assessment if there are a number of existing wind farms in the surrounding area.
- A night lighting assessment, if applicable.
Response:
- Mitigation measures to avoid, minimise or mitigate negative landscape impacts. It's important to get community input for this section.
- Visual assessment and mitigation measures for selected private residences if desired by the proponent or specifically requested by the planning authority.
Perception studies
Perception studies (surveys of public opinion of wind farms) are often used in visual assessments of wind farms. The perception studies done to date show a high level of public acceptance for wind farms in Australia.
You can use these studies to show the majority of people view wind farms in a positive light, mainly because people associate wind farms with renewable energy and positive action on climate change. Additionally wind farms can be attractive, sculptural features on the landscape.
If you're considering conducting a public perception survey as part of your visual assessment, be sure to ask objective questions (not leading questions that direct a particular response). You can use the National Assessment Framework as a key reference when you start to prepare your survey.
Visual consultants
The visual assessment of wind farms is still a specialist area, which currently has very few experienced practitioners in Australia and New Zealand.
Look for a consultant with:
- previous wind farm experience
- an understanding of the National Assessment Framework
- experience of gaining community input
- reasonable costs and availability.