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Bushfire safety: ground-fire bow-tie

Information on how businesses need to meet obligations to minimise bushfire risk.

Purpose and scope

This publication provides information on how responsible businesses need to meet their obligations to operate and maintain their electricity networks to minimise bushfire risk. This publication also outlines ESV’s oversight and regulatory activities specific to identified controls using bow-tie methodology. It supports responsible parties to better understand bushfire risk, and may also be of interest to members of the public.

This document provides an overview of obligations under the energy safety legislation, however it is not a complete statement of the legislative requirements or what is required to meet those requirements. This document does not affect the operation of the Electricity Safety Act or the Regulations made under that Act. Persons with obligations under the legislation should consider their own specific circumstances.

Background

Victoria has a history of electricity assets causing bushfires and is identified as one of the world’s areas most prone to bushfire. In 1969 and 1977 the failure of electricity assets—including the clashing of conductors, conductors contacting trees, and inefficient fuses—caused major bushfires. This history was repeated on 7 February 2009, when five of the 11 major fires that began that day were caused by failed electricity assets; among the fires was that at Kilmore East, which resulted in the death of 119 people. Part of our purpose is to promote the prevention and mitigation of powerline bushfire danger to ensure the likelihood and consequences of such events are minimised.

It is appropriate that our discussion of harms begins with bushfires, given that among all the areas that we regulate, bushfires pose grave risk to the public — multiple fatalities and injuries, loss of property and livestock, economic impacts and costs of recovery.

It is important we are transparent with our stakeholders and the community about how we ensure the responsible businesses meet their obligations to operate and maintain their electricity networks to minimise as far as practicable the bushfire risk. We have developed a bowtie diagram (see below) to help communicate the threats from electricity networks that could result in a bushfire, and the controls to manage these.

As the safety regulator, our role is not to manage the risks that may occur when operating electricity networks. ESV’s objectives and functions with respect to electricity networks is outlined in sections 6 and 7 of the ESA. The functions of ESV include encouraging and monitoring the use of ESMSs and regulating, monitoring and enforcing the prevention and mitigation of bushfires.

It is therefore important to note that our bow-ties show industry risk controls; the corresponding ESV regulatory assurance activities are listed separately (table 1).

ESV applies a safety assurance focus and regulates, monitors and enforces industry safety and compliance with regard to risks that arise from industry activities. We accept /approve ESMSs, BMPs and ELCMPs (plans) which describe how the responsible party will manage bushfire risk. ESV monitors compliance against submitted plans through audit and inspection activities. Bow-ties help ESV understand the controls industry has in place in managing bushfire risk, in order to target audit and inspection activities. In the case of an ESMS, ESV may require that a bow-tie developed by the responsible party be provided as part of its formal safety assessment prepared for the ESMS.

Using a bow-tie diagram

Bow-ties are a valuable risk analysis tool and visual representation of key risk information, such as critical controls. The reasons we use bowtie diagrams are that:

  • They provide a consistent and structured way to assess the risks being managed by industry.
  • They provide a summary of risks associated with the hazard (electricity network) that is easy to understand.
  • Their branching structure allows us to quickly see the different threats (causes) and consequences and whether the set of controls is acceptable.
  • They allow us to monitor the health of controls and target areas where controls are starting to fail.

When we work with bow-ties, we consider the following (see diagram 1):

  1. The hazard (i.e. electrical distribution lines)
  2. loss of control event (i.e. ground-fire).
  3. the threats that cause loss of control of the hazard (i.e. tree branch falling onto powerline),
  4. consequences of losing control.
  5. controls for each threat that would prevent the threat from happening (i.e. cutting back vegetation),
  6. mitigating actions that will prevent or reduce the consequences from occurring if the loss of control event occurs.

Diagram 1:

A bow-tie diagram for ground-fires, showing 6 stages.

Understanding bushfire risk

In understanding bushfire risk, we consider a high level view of the range of environmental, human, design and operational threats that could start a ground-fire (leading to bushfire) and identify the main threats that are most likely to cause a bushfire if not managed by the responsible businesses.

Click here to see our ground-fire risk bowtie:

Ground-fire bow-tie 2023
PDF 370.07 KB
(opens in a new window)

ESV regulatory action

The Electricity Safety Act 1998 and its subordinate regulations establish the duties and obligations on responsible parties to minimise hazards and risks arising from network assets

We audit and inspect to ensure that the risk controls are being implemented effectively and that the responsible businesses comply with their documented systems and plans. When they do not meet their obligations, we will investigate further to ascertain the cause of any non-compliances. We will then consider taking proportionate enforcement action, consistent with our compliance and enforcement policy:

ESV_ComplianceAndEnforcementPolicy_2021
PDF 104.59 KB
(opens in a new window)

Please see below table 1 for a summary of ESV’s regulatory assurance activities associated with ground-fire risk.

Table 1: ESV regulatory & assurance activities

ESV regulatory & assurance activities

Vegetation Clearance

(see ground-fire bow-tie threat “vegetation grow-in” and “vegetation falling/blowing onto live electrical asset”)

Vegetation clearance around powerlines is one of our compliance and enforcement priorities.

Relevant legislation

Electricity Safety Act 1998 Division 2 Subdivision 1 Section 84 (distribution companies), 84A and 84B (occupiers of land), 84C (councils) and 84D (other persons)

Electricity Safety (Electric Line Clearance) Regulations 2020 that include the Code of Practice for Electric Line Clearance

ESV oversight activities

  • Review and accept ESMS and bushfire mitigation plans
  • Review and approve ELCMPs (Electric Line Clearance Management Plans) of responsible persons
  • MEC reporting of clearance activities monthly (May to August) and weekly during fire season (September to April)
  • Compliance audits and inspections
  • Investigation and enforcement action, where necessary
    (refer to the Electricity Safety Performance Report 2021 for examples of recent and ongoing enforcement activities)
    Missing media item.
  • Issue notices pursuant to the Act for cutting or removal of non-compliant vegetation

REFCL

(see ground-fire bow-tie, all threats)

Rapid Earth Fault Current Limiters (REFCL) are being deployed at substations servicing high-risk areas within Victoria’s electricity network. REFCLs are a new type of protection system that prevents fire ignition arising from phase-to-ground faults. ESV is overseeing the deployment and testing of REFCL systems. Further details on the REFCL program can be found on the DEECA website (overview) and on the ESV website (details and status). ESV is monitoring the Rapid Earth Fault Current Limiter (REFCL) roll-out that is due for completion by 1 May 2023.

Relevant regulation

Electricity Safety Act 1998 Sections 120K, 120L and 120M

Electricity Safety (Bushfire Mitigation Duties) Regulations 2017

Electricity Safety (Bushfire Mitigation) Regulations 2013

ESV oversight activities

  • Review and approval of BMP five-yearly (MECs)
  • Progress reviews of the REFCL deployment program & observing REFCL testing
  • Undertaking annual reviews of network faults
  • Commissioning an independent functional performance review
  • Weekly fire season reporting of REFCL operations
  • Audit of MEC compliance with BMP
  • Investigation of incidents (annual Network Safety Performance report)

Hazard tree management

(see ground-fire bow-tie, vegetation falling/blowing onto live electrical asset threat)

It is a requirement of:

  • the Electricity Safety Act 1998 for a major electricity company to operate and maintain its electricity supply network to minimise, as far as practicable, the hazards and risks to the safety of any person, damage to any property and bushfire danger arising from the network. This includes hazard tree management
  • the Emergency Management Act 2013 for municipal councils to have procedures and criteria for identifying hazard trees and for notification procedures for the notification of responsible persons of those hazard trees.

Relevant legislation (MEC)

Electricity Safety (Electric Line Clearance) Regulations 2020, Schedule 1 Section 9

ESV oversight activities

  • Evaluation, review and approval of ELCMPs
  • Compliance audits
  • Hazard tree inspection
  • Relevant legislation (Municipal Councils)

    Section 86B of the Electricity Safety Act 1998 Act 1998 - Municipal emergency management plans must specify procedures for the identification of trees that are hazardous to electric lines. Please also refer to the Emergency Management Act 2013.

    ESV oversight activities

  • Compliance audits
  • Hazard tree inspection

Powerline / Electrical Assets

(see ground-fire bow-tie, “electrical asset failure or operation” and “animal and bird contact with live electrical asset”)

Improving powerline maintenance of major electricity companies is one of our compliance and enforcement priorities for 2022-2023, which builds upon earlier work on wood pole management that was a priority in 2021-2022. A list of reports on the incidents leading to and the activities of this program of works can be found here. This also extends to the selection and application of asset types that are appropriate for the risks and environmental conditions of the local area, e.g. low fire risk products installed in hazardous bushfire risk areas.

Electrical assets must be selected, designed and constructed in accordance with the ESMS or standards. The inspection, maintenance and replacement of electrical assets must be conducted as per the accepted BMP.

Relevant regulation

Electricity Safety Act 1998

Electricity Safety (Bushfire Mitigation) Regulations 2013

Electricity Safety (Management) Regulations 2019

ESV oversight activities

  • Review and acceptance of ESMS five-yearly (or as required)
  • Review and approval of BMP five-yearly (or as required)
  • Audits and inspections
  • Targeted audits and assessments
  • Investigation of incidents and complaints about industry made by industry participants and the community

Third party contact (vehicles, equipment, etc.)

(see ground-fire bow-tie, “third party contact”)

Minimising energy network strikes and encroachments is one of our compliance and enforcement priorities for 2022-2023. ESV is working with WorkSafe and industry participants to raise awareness of the dangers of working in close proximity to powerlines, to promote the No Go Zone rules, encourage the adoption of safe systems of work, and to promote the use of proximity devices and early warning systems when working near powerlines. In addition, MECs are required to implement controls in accordance with their accepted ESMS or BMP, such as installing markers and signage to show location and provide warning, controlling work activities around powerlines through permit to work systems, implementing REFCL protection, de-energising powerlines on high risk days, running Public Awareness Campaigns (promotion of No Go Zones) and providing Network Location Resources (Before You Dig Australia and the Look Up and Live App).

Relevant regulation

Electricity Safety (General) Regulations 2019

Electricity Safety Act 1998

Electricity Safety (Management) Regulations 2019

Electricity Safety (Bushfire Mitigation) Regulations 2013

Electricity Safety (General) Regulations 2019

ESV oversight activities

  • Review and acceptance of ESMS five-yearly (or as required)
  • Review and approval of BMP five-yearly (MECs) or annually (SOs) or as required
  • Audit of MEC compliance with ESMS and BMP
  • Inspections of electrical assets
  • Investigation of incidents
  • Public awareness campaigns
  • Delivering industry training and awareness sessions
  • Registration of spotters

Date: 12/07/2024 17:49

The currency and accuracy of this information cannot be guaranteed once printed or saved to a storage device. If in doubt, please check the Energy Safe Victoria website for the current version.

Reviewed