Bushfire, flooding and safety FAQs

Bushfire risk will be considered at every stage of planning and design for VNI West.

The project must go through a strict regulatory environmental and planning approvals process before it is approved by Government. As part of this, a detailed fire risk assessment must be conducted in the coming 12-18 months by an independent expert, which will require consultation and input from fire authorities including the CFA. A preliminary bushfire risk assessment has already been carried out, including consideration of high-risk areas, which fed into the development of the draft corridor.

We will continue to work with the fire authorities and safety regulators to provide answers to the community on their questions about managing bushfire risk. The attached brochure Bushfire Management and Community Safety from Energy Safe Victoria provides some excellent information about guidelines relating to bushfires and transmission.

In Victoria, there are currently around 6,500 kilometres of transmission lines. Bushfires have been managed and successfully fought around transmission infrastructure for decades. The network operator (TNSP) is required to work with fire authorities to ensure that any bushfire in the area can be fought, including aerial firefighting capability.

The TNSP has a commitment to provide its customers with a reliable and safe electricity supply.

In the event of a bushfire, it will work closely with Emergency Management Victoria (EMV), Fire Rescue Victoria (FRV), Country Fire Authority (CFA) and Forest Fire Management Victoria (FFMV) and follow all agreed and mandatory directions.

If required, this can include turning off the power across parts of the transmission network.

The Australian Energy Infrastructure Commissioner, the CFA and Energy Safe Victoria have recently published a bushfire and transmission information brochure. This covers how the companies that own and maintain transmission lines work with fire authorities to ensure that aerial firefighting is possible in the vicinity of transmission lines.

The design and specifications of VNI West assets will factor in location-specific conditions, including maximum anticipated wind speeds, to minimise the risk of failure even in extreme circumstances throughout the asset's life.

The operation, monitoring and maintenance of transmission infrastructure is highly regulated. The VNI West transmission line owner and operator will oversee tower maintenance activities including corrosion monitoring, routine maintenance, inspections and vegetation clearance.

Fires near or under transmission lines can damage or destroy conductors and insulators, interrupting electricity supply to customers.

Smoke from fires near or under transmission lines can create electrical arcs or flashovers. Terminal stations and transmission lines are remotely operated and can be shut down when required. If a fault were to occur on the transmission network, the protection systems in place would quickly detect the fault and switch off the power in response, to prevent an electrical fire.

For a fault on a 220kV transmission network, the system response to turn off power generally takes place within 120 milliseconds (0.12 of a second). Similarly, for a fault on a 500kV transmission network, power is generally turned off within 80 milliseconds (0.08 of a second).

Transmission lines have ground wires at the top of each tower. These shield the transmission lines from lightning strikes, by directing the power in a strike safely into the ground and away from transmission lines.

Redirecting lightning strikes safely to ground allows the electricity supply to be maintained without interruptions, avoids damage to network infrastructure, and reduces bushfire risks in the immediate area. Ground wires are an essential part of a safe and reliable transmission network.

Transmission lines are highly unlikely to cause fires. There is one recorded instance where a structure failure triggered a small ground fire, which was quickly extinguished by the rain. Modern transmission lines are better equipped to withstand extreme weather, reducing the risk of structural failures.

For information on mitigating fire risks, please visit the TCV website and access our Managing fire risk across the electricity transmission network factsheet.

There are no significant health risks to those living close to high voltage transmission lines (500kV or 200kV).

After a multitude of studies on the concerns and potential health impacts on individuals, the Australian Radiological Protection and Nuclear Safety Advisory (ARPANSA) has said there is no scientific evidence to establish that exposure to electromagnetic fields around the home, the office or near power lines causes health effects. Despite this, a precautionary approach will be applied to managing electromagnetic fields, including targeting minimum setbacks from residences and monitoring power lines for electromagnetic field intensity.

Electric and magnetic fields, commonly known as EMFs, are both naturally occurring and found wherever there is electricity. Natural occurrences include from lightning, solar activity and the earth itself. All living organisms produce EMFs. Wherever electricity is flowing or there is an electrical force, EMFs are produced.

The levels emitted by high voltage transmission lines are well below the public exposure limit of 2,000 mG recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), which released an international standard in 2010.

In general, TCV will seek to identify options that avoid flood prone areas as much as practical, while also considering all other relevant constraints.

Flood and weather risks are considered through the design, construction and operational phases of a high voltage transmission project.

During the design phase of a transmission infrastructure project, towers and terminal stations are designed:

• With consideration to the flood levels, flood risk and geotechnical conditions of the infrastructure locations
• To address and withstand (in accordance with relevant design principles) weather conditions
• By implementing a Safety in Design process to review the risks associated with construction and operation of the assets
• During the construction phase of a project, various measures are put in place to manage and mitigate weather risks, including preparing relevant safety management plans
• Monitoring weather situations in the operation of the electricity network.

Transmission network service providers (TNSPs) are committed to managing flood and weather risks associated with the electricity transmission network assets.

There are no significant health risks to those living close to high voltage transmission lines.

500kV transmission lines generally emit 10-50mG at the edge of a high voltage transmission line easement and 20-200mG directly under a high voltage transmission line.

This is significantly below the international standard for human exposure limit of 2,000 mG As recommended by the International Commission on Non-Ionizing Radiation Protection (ICNIRP 2010).

There have been almost 3,000 studies carried out in relation to EMFs and the scientific evidence does not establish that exposure to EMFs found around the home, the office, near power transmission lines or other common electrical sources is a hazard to human health.