UNCLASSIFIED

UNCLASSIFIED

ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Presentation to Powerline Bushfire Safety Committee – 13 June 2017

Approach to targeting areas/powerlines of high bushfire risk

Julian Kucherhan, Powerline Bushfire Safety Program

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Government response to powerline bushfire risk

Feb 2009 The VBRC was established to respond to the Black Saturday bushfires.1

Jul 20102 The VBRC released its recommendations, eight of which relate to

electricity distribution.

Sep 20103

A Taskforce was appointed to advise how best to implement

recommendations 27 and 32, which were held to be of considerable

technical complexity

Sep 20114 The Taskforce produced its final report to Government.

Dec 20115 The Government issued its response to VBRC recommendations 27

and 32, which also constituted its response to the Taskforce report.

The PBSP was established by the Government in December 2011 for

the express purpose of implementing VBRC Recommendations 27 & 32 Dec 20116

UNCLASSIFIED

UNCLASSIFIED

ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

PBSP & the implementation of VBRC Recommendations 27 & 32

The Mandate

The Victorian Government

established PBSP in December

2011 to implement VBRC

Recommendations 27 and 32.

FoundationEstablishment of structures, instruments and controls necessary to enable effective and efficient delivery.

1

InitialDelivery

Highly targeted delivery to make use of allotted funds and appraise implementation methods and processes.

2

RegulatoryEnablement

The formulation of regulatory amendments to remove barriers to the realisation of targeted powerline bushfire safety benefits.

3

RegulatoryApplication

Full scale delivery within the revised regulatory framework supported by ongoing monitoring of regulatory compliance.

4

Legacy ofraised standards

Sustained patterns of industry investment in bushfire safety infrastructure and operations, consistent with new codified bushfire safety standards.

5

2012

2013

2014

2015

2016

2022

The Approach

The Priority

The PBSP is a strategic

Victorian infrastructure

program with an unambiguous

imperative to deploy safer

powerline assets.

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Imperative for effective geographic targeting

Problem: High Voltage (HV) powerlines have been found to cause bushfires

Scale: There are over 90,000 kms of HV powerlines in Victoria

Risk (total): All HV powerlines carry some risk of causing ignitions

Solution (total): Placing all HV lines underground would cost $40 billion ($ 2011 real)

PBSP Scope: PBSP must introduce its initiatives within 10 years using no more than $750 million

PBSP is required to target investment at areas of highest bushfire risk as a priority

The identification of precise geographic targets has been critical to the effort to

maximise the reduction in powerline bushfire risk.

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Determining geographic priorities – the framework

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Responding to different levels of locational risk

REPRESENTATION OF HV NETWORK BUSHFIRE RISK

Powerline Bushfire Safety ProgramRisk Targeting Concept

Risk Profile of Target Line

Length of line to protect

Optimal Asset Treatment

Length protected by

Treatment

Relative cost of Treatment

VERY HIGHLOW

Highly targeted

Powerline Replacement

SHORT VERY HIGH

HIGH to VERY HIGH

VERY LARGEBroadly targeted

REFCLs VERY LONGLOW to

MEDIUM

LOW to VERY HIGH

VERY LARGEAll lines in scope

ACRs LONG VERY LOW

Risk profile of target locations

Low to High

High to Very

High

Very High

Powerline Replacement

REFCLs

ACRs

The targeting strategy assumes

that those locations of highest risk

receive all treatments available

under VBRC Recommendation 27

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Fire Loss Consequence

PBSP Powerline

Profile Model

FireIgnition

Likelihood

Fire Response

Complexity

How many lives and properties will be lost if

a fire starts on a particular powerline?

How likely is it that a fire will start

on any individual powerline? How difficult is it to fight a fire

and protect people if a fire starts

on a particular powerline?

Risk Profiling Model

Powerline risk profiling - a three part precautionary approach

Assessment

ApproachStatistical analysis(to deal with the scale and

complexity of data)

GIS framework(to enable locational

alignment of variables and

aid visualisation)

Operational

Knowledge(to be informed by history

and practical awareness)

1 2 3

+ +

UNCLASSIFIED

UNCLASSIFIED

ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

What data/resources are used/managed to guide targeting?

Phoenix RapidFire

A tool developed by a team at Melbourne

University that:

• models fire behaviours under different

weather/vegetation conditions; and

• estimates the fire loss (consequence)

at 27,860 ignition points.

Powerline Data

Engineering data provided by industry that:

• identifies the location of assets;

• defines the protection technology

installed; and

• places these within a network

structure.

Risk Reduction Model

A model developed by CSIRO to:

• calculate the likelihood of ignition

under different scenarios;

• model the reduction in ignition risk that

can be achieved using specific

technologies in specific locations; and

• estimate relative risk for any part of the

network (likelihood x consequence).

Victorian Fire Risk Register

A risk assessment tool developed by the

Country Fire Authority that:

• captures data about the risk exposure

for four classes of “asset”; including

• one important “asset” for PBSP, human

settlements.

GIS Database

A geo-spatial database managed by GT that:

• integrates all data layers;

• records changes over time; and

• allows the visualisation of the

interaction/relationship between data

layers.

Emergency Mgt Analysis

A person based assessment of risk

relativities, taking account of:

• fire history;

• fire suppression complexity;

• population evacuation options and

• all other qualitative knowledge.

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Key Quantitative Inputs – Fire Consequence and Ignition Likelihood

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Fire loss consequence modelling – Phoenix RapidFire 2014/15

Phoenix Rapid Fire was used to model bushfire behaviour on the basis of these parameters:

Forest Fire danger Index (FFDI) of 140, but with weather moderated for elevation effects on temperate

and attendant relative humidity – this FFDI level is consistent with the conditions on Ash Wednesday;

weather patterns assumed to follow Ash Wednesday events;

ignition points based on a 2km grid state-wide, but only points within one kilometre of 22kV and

SWER powerlines (27,860 ignition points);

long-unburnt fuels (i.e. assumes ‘worst case’ fuel load, not taking the recent fire history into account);

low level suppression response (i.e. equivalent to first attack response);

worst-case grassland curing conditions based on driest years in the past decade;

ignition time assumed to be as soon as the FFDI reaches 24 or if this level is not reached, then at the

time of maximum FFDI for the day; and

the probability of ignition was assumed to be uniform across the State.

UNCLASSIFIED

UNCLASSIFIED

ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Since 2011, Phoenix RapidFire has been used to model fire

behaviour.

The model is used to estimate the number of houses that would be

lost to a fire starting on a powerline.

The estimates are generated for 27,860 ‘ignition points’

Red and purple areas on maps represent points at which a fire

ignition is estimated to result in house losses > 2,000.

PBSP uses maps to identify the areas of highest bushfire risk to be

targeted under the program as a priority

Identifying areas of high fire loss consequence – ignition points

This scenario assumes Ash Wednesday conditions & no burning off

(that is: all targeting tests for risk exposure under worst case conditions)

Phoenix RapidFire map for 2014/15 (Scenario: AN 140)

The protection and

preservation of life is

the primary

consideration

Targeting therefore

focusses firstly on areas

with highest estimates

of property loss

PBSP is a long term

strategic program to

mitigate risk around

extreme events and so

model AN 140 is used

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

PBSP Risk Reduction Model (RRM) and ignition likelihood

The RRM was designed to estimate the

relative reduction in powerline ignition rates

achieved when unprotected HV bare-wire

powerlines are protected by:

• Replacing bare-wire powerlines

• Automatic Circuit Reclosers

• Rapid Earth Fault Current

Limiters

Type

SWER1

2 2 kV1

ACR operating on bare-wire -35% to -40% -7% to -10%

REFCL operating on bare-wire N/A -48% to -60%

Insulating bare-wire -96% to -98% -96% to -98%

Undergrounding bare-wire -98% to -99% -98% to -99%

Reduction in ignition likelihood

Source: PBSP Risk Reduction Model, CSIRO, July 2016

Ignition likelihood rates were estimated for

multiple asset classes using tens of thousands of

historical powerline fault and ignition records

Estimated reduction in ignition rate by asset intervention

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Focus of ignition likelihood modelling

Each fault/ignition record was categorised by:

Line Type: whether the HV line is SWER or 22 kV.

Situation: the terrain and type of vegetation that is present at the location, or possible

locations, of the fault (in practice, four vegetation types and a measure of slope are used).

Conditions: the meteorological conditions (wind speed, temperature, environmental

dryness (KBDI) and relative humidity) at the time of the fault.

Cause: the cause of the fault, which is assigned in the data to one of eight broad

categories and a few dozen detailed cause types.

Asset impact: the primary asset impact of the fault, that is, which part of the system was

directly damaged and potentially emitted arcs, particles or burning material which could

start a fire.

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UNCLASSIFIED

ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Combining likelihood and consequence data

x.x%

Powerline Bushfire Safety ProgramIndicator 1 – Risk Reduction Calculation

Powerline protection by poleat start of period(1 January 2012)

Powerline DataPowerline protection by pole

at end of period(30 June 2016)

Ignition Likelihood

Estimated ignition rate by pole(1 January 2012)

aEstimated ignition rate by pole

(30 June 2016)b

Estimated change in ignition rate by pole

a b- c=

Risk Reduction Metric

Fire Loss Consequence

Tolhurst property loss (AN 140) estimates by ignition point

Estimate of property loss by pole

d

Estimate reduction in powerline risk by pole

c dx e=Statewide reduction in powerline bushfire risk

16.0%∑ e

x.x%

UNCLASSIFIED

UNCLASSIFIED

ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Defining Electric Line Construction Areas

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UNCLASSIFIED

ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Considerations for nomination of areas of highest bushfire risk

A. Fire carry and consequence

1. Fire Loss Consequence estimates @ Forest Fire Danger Index FFDI 140 – extreme conditions

2. Fire Loss Consequence estimates @ Forest Fire Danger Index FFDI 70 – TFB conditions

3. Fire carrying capacity of environment

Looking for clusters of ignition points with estimated property losses exceeding 2,000

Looking for clusters of ignition points with estimated property losses exceeding 500

Looking for vegetation capable of carrying fire over distance

B. Exposure of people to bushfire risk

4. Likelihood of ignition

5. Proximity of population to point of ignition

6. Fire suppression capability

Consider the likelihood of ignition using the CSIRO modelling of historical fault/ignition data.

The more people there are close to a point of ignition, the greater the likelihood that people will be harmed

Consider how close fire fighting resources to a point of ignition

7. Quality of access /egress routes Consider how easy or difficult it is to deploy suppression resources and evacuate affected populations.

These considerations

are based upon those

originally developed

to select the first

3 areas targeted for

powerline

replacement in 2013

These considerations

informed the

selection of a further

30 areas of the

highest bushfire risk

in 2015

Electric Line

Construction Areas

codified in Bushfire

Mitigation Regulations

33

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Identifying areas of high powerline bushfire risk

1. Consider clusters of high consequence points

Maps were used to review fire loss consequence

exposure at FFDI 140 and FFDI 70 for over 50 Local

Government Areas in rural Victoria and on the peri-

urban fringe of Melbourne

Identified cluster of

ignition points

The modelled fire spread from each ignition polygon

was used to review:

the vegetation characteristics and how they may

contribute towards rapid fire spread; and most

importantly

the location of population in the area of fire

spread and their proximity to the initial fire

source

2. Investigate modelled fire spread

3. Explore other risk factors

Other inputs to deliberations were:

the bushfire risk of powerlines (likelihood x

consequence), based on the analysis of the CSIRO;

the availability of fire suppression resources

proximate to the fire source; and

the availability of road infrastructure to enable the

delivery of a fire response and evacuate people in

the fire path.

Maps and specialist

Geographic Information

System (GIS) software were

used to investigate and

visualise these important

decision elements

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Based on information provided by PBSP, the

Commissioner determined:

the three PRF Initial Target Areas to be targeted under

the PRF Project; and

a further 30 areas of very high bushfire risk in which

heightened powerline construction standards would

apply.

Under PBSP governance arrangements, all determination

about geographic scope are subject to a determination

by the Emergency Management Commissioner Victoria.

4. Determination and boundary definition

Determination

Eleven of the 33 areas have been targeted for immediate

treatment via the PRF Project.

AusNet Services and Powercor provided advice to

ensure that scope inclusions/exclusions (relative to

target areas within their service catchment) were

practical, considering:

network structure (zone substations, feeders, etc.);

powerline voltage (22kV and SWER); and

other logical demarcation considerations (e.g. alignment

to natural and man-made boundaries – rivers and

roads).

While the Commissioner established the areas to be

targeted, the final positioning of boundaries was

established after operational factors were considered.

Boundary definition

All 33 areas were subject to this definition process (re-

definition in the context of the 3 PRF Initial Target Areas).

UNCLASSIFIED

UNCLASSIFIED

ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Selecting zone substations for enhanced 22kV fault suppression

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Setting targets to maximise the benefits of REFCL deployment

Targets reflect the early approach to REFCL deployment priority, which considered the total

kms of 22kV lines that were exposed to modelled fire loss of 1,000+ and 2,000+ properties.

REFCL DEPLOYMENT OBJECTIVES

By deploying REFCLs at targeted Zone Substations, the State is seeking to:

achievereduction in State-wide powerline

bushfire risk.> 40%

protect of 22kV powerlines.> 30,000

protectof 22kV powerlines of high fire loss consequence (1,000 + properties).> 95%

protectof 22kV powerlines of very high fire

loss consequence (2,000 + properties).> 98%

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Considerations for Zone Substation targeting

A Zone Substation (ZSS), each of which encompasses multiple feeders, was selected as the unit of deployment as that

was the level at which stakeholders agreed that a Rapid Earth Fault Current Limiter (REFCL) would operate.

1

For each ZSS, a risk ‘Benefit’ was calculated (based on CSIRO ignition likelihood and Phoenix RapidFire consequence –

AN140), reflecting the contribution that a REFCL would make to risk reduction at each location.

2

For each ZSS, a REFCL ‘Cost’ was estimated - based on ACIL Allen cost estimates for the 42 ZSSs incorporated in the

Regulatory Impact Statement for the Bushfire Mitigation Regulations.

3

For each ZSS, a flag was raised where some part of the powerline network overlapped one of the 33 Electric Line

Construction Areas.

4

The fourth consideration provided a basis for incorporating the ‘qualitative’ dimension of the earlier targeting process

and for aligning the REFCL program to areas of the highest risk

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Ranking and selecting Zone Substations

ZSSs were ranked in two different ways

1

1. Total Risk Benefit

2

2. Cost per 1% of Risk

Benefit3. Add ELCA Flag

ANDSelection

Steps

Select each ZSS that is ranked in the top 20 ZSSs in both

rank orders.

Select each ZSS that

overlaps an ELCA.

3

Select further ZSSs based

on cost-benefit until 95% of

22kV kms with 1,000+

consequence protected.

Note: 4 ZSSs linked to an ELCA were not selected at STEP 2 (one due to short route length and 3 due to >90% of line length

traversing lower risk areas).

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ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

The geographic footprint of REFCL deployment

This map illustrates the

coverage provided by

placing REFCLs in the

45 highest priority Zone

Substations

This deployment will

deliver risk benefits:

in locations of

highest risk

across more than 30,000

kms of multi-phase

powerlines

within seven years

Victoria is the first jurisdiction world-wide to use REFCLs for

bushfire safety purposes.

Testing indicates that REFCLs will prevent over half the ignitions

on the lines that they protect

UNCLASSIFIED

UNCLASSIFIED

ENVIRONMENT,DEPARTMENT OF

LAND,

AND PLANNINGWATER

Thank you and questions