Building Resilience to Climate Change

Building Resilience to Climate Change Climate Change Risk Assessment & Adaptation Options for Council Assets Report for City of Wagga Wagga 2018

Project Delivered for: City of Wagga Wagga 243 Baylis Street (PO Box 20), Wagga Wagga NSW 2650 Project Delivered by: Edge Environment Level 5, 39 East Esplanade, Manly, NSW 2095, AUSTRALIA

Project Funded by: ‘Building Resilience to Climate Change’ partnership program between LGNSW and the NSW Office of Environment and Heritage (OEH) to address identified climate change risks and vulnerabilities facing NSW Councils.

Revision

Revision Details

Author

Approved by

Date Approved

A

Initial issue for comment

Nicole Thompson & Joel Clayton

Tom Davies

08/12/2017

B

Integrated WWCC comments

Nicole Thompson & Joel Clayton

Tom Davies

22/01/2018

C

Further WWCC amendments

22/09/2018

Executive Summary Wagga Wagga City Council (WWCC) is located in the Riverina region of NSW on the Murrumbidgee River. Wagga Wagga is the largest population centre in the Riverina region providing a central hub of services to a catchment of over 180,000 people.

Climate change is projected to impact upon this area, leading to potentially unforeseen risks to the built environment, with important economic, environmental and health implications. The development of a Climate Change Risk Assessment & Adaptation Options Report provides both operational and future recommendations that help to manage risks appropriately, ensuring the climate resilience of these assets into the future.

The objectives of this Climate Change Risk Assessment & Adaptation Options Report are to: 

Provide an understanding of localised climate change projections for the Wagga Wagga Local Government Area



Present a climate change risk analysis for the selected WWCC assets



Develop a report outlining proposed adaptation actions

A workshop was held with the selected Project Working Group (PWG) to review the likely climate change impacts and identify and assess risks to assets. The Council manages a range of different types of assets in the local area from amenities and sporting facilities to sewerage treatment plants (STP) and the Livestock Management Centre. The WWCC assets, as chosen by the PWG, were assessed.

“Adaptation Actions” required to treat significant risks were developed and then reviewed by the PWG after the workshop. Risks were then reassessed, considering the relevant adaptation actions, and given a revised risk rating.

A total of 38 climate change related risks to assets were identified in the risk workshop presented to the WWCC PWG. These risks are associated with several common climate variables such as increase in hot days, increase in flooding and increased rainfall variability. An increase in hot days generated the most risks in the analysis, and were dominated by the impacts; pumping failures, infrastructure and vegetation damage, and an impact on public health. Increased rainfall variability and increased intensity of storm events also pose a high number of risks and impacts relating to maintaining STP processes, aquatic health, increased reliance on irrigation and sewer and detention basin overflows. Increase in flooding and increased average temperature both have a number of similar impacts.

These risks and their adaptation actions were given a priority rating of low, medium and high derived from a rating score based on four factors; risk rating, asset renewal data, cost and practicality to implement. Table 1 provides a summary of the identified risks, their relevant adaptation actions, and their priority rating given for implementation and management of these risks.

It is recommended that Council incorporate priority actions into their Integrated Planning and Reporting processes, and ensure that an updated analysis of risks is undertaken on a regular basis in line with Council’s Risk Management Framework.

Table 1 - Summary of adaptation actions required to achieve revised risk rating

Risk

Risk Rating

Adaptation Actions

Before/After

Priority to Implement

TRN1

High - Medium

Increase urban canopy along shared pathways

High

REC1

High - Medium

Implement relevant actions from the Recreation Open Space Community Strategy to increase shading at playgrounds, sportsgrounds and parks

High

Develop a Heatwave Management Plan REC2

High - Medium

Install water efficient irrigation systems

High

Ensure plant selection is appropriate for hotter, drier conditions SEW2

High - Medium

Install permanent generator or alternate off-grid option for each pump site

Medium

Evaluate the adequacy of emergency storage capacity at each treatment plant SEW3

High - Medium

Investigate feasibility of oxygen injection and odour control methods

Medium

SEW4

High - Medium

Identify specific flood prone assets and evaluate site specific opportunities to move or protect asset

Medium

Implement actions from the Floodplain Risk Management Plan and the Sewer Asset Management Plan STM1

High - Medium

Implement actions from the Floodplain Risk Management Plan and the Stormwater Asset Management Plan

Medium

Review modelling and design requirements to allow for greater flow volumes Review and upgrade capacity of pumps as needed TRN2

High - Medium

Utilise materials and designs for pavements and surfaces that are highly resistant to high temperatures

Medium

TRN3

High - Medium

Implement actions from the Floodplain Risk Management Plan and the Transport Asset Management Plan

Medium

Utilise materials and designs for pavements that are highly resistant to inundation Retain flood paths in new developments REC3

High - Medium

Install water efficient irrigation systems as per the irrigation audit Install tolerant or synthetic turfs Investigate diversifying water sources to include stormwater, greywater or blackwater

Medium

REC4

High - Medium

Implement actions from the Floodplain Risk Management Plan and the Recreation Asset Management Plan

Medium

Utilise materials and designs for built recreational assets that are highly resistant to high temperatures and frequent inundation BLD3

High - Medium

Identify and implement energy efficiency initiatives at Council buildings

Medium

Investigate feasibility of passive cooling projects such as green roofs and heat reflective surfaces BLD4

High - Medium

Implement actions from the Floodplain Risk Management Plan and the Buildings Asset Management Plan

Medium

Modify design and construction of future assets for increased Probable Maximum Flood levels BLD5

High - Medium

Undertake site specific risk assessments to identify vulnerable assets and evaluate options to move or protect asset

Medium

Modify design and construction of future assets for increased Bushfire Attack Levels REC5

High-High

Implement site specific Plans of Management

Medium

Divert stormwater where feasible Investigate options for de-silting, use of treated effluent and algal control measures BLD1

Medium-Low

Investigate options for increasing shade and water infrastructure

Medium

SEW1

Medium-Low

Implement a targeted inflow and infiltration prevention program to minimise increase in volume of water in sewer network from rainfall events

Medium

Develop a program of indoor demand management activities to reduce load on sewer network Identify energy efficiency measures for assets SEW5

Medium-Low

BLD2

High-Low

Identify specific bushfire prone assets and evaluate site specific opportunities to move or protect asset

Low

Utilise materials and designs that are highly resistant to high temperature

Low

Executive Summary .................................................................................................. 3 1

Introduction ........................................................................................................ 7 Objectives ................................................................................................................ 7

2

Methodology ....................................................................................................... 8 Background Research ............................................................................................ 8

3

Climate Analysis............................................................................................... 10 Historic climate for Wagga Wagga....................................................................... 10 3.1.1

Temperature ..................................................................................................... 10

3.1.2

Rainfall ............................................................................................................. 11

3.1.3

Extreme weather events ................................................................................... 12

Climate change projections ....................................................................................... 13

4

3.2.1

Average Temperature & Hot days .................................................................... 13

3.2.2

Rainfall ............................................................................................................. 14

3.2.3

Extreme weather events ................................................................................... 14

Risk Assessment & Adaptation Actions ........................................................ 15 Risk Workshop ...................................................................................................... 15 4.1.1

Workshop ......................................................................................................... 15

Risk assessment matrix ........................................................................................ 19 4.2.1

Risk Assessment outcomes ............................................................................. 19

Risk Summary and Evaluation ............................................................................. 30 Adaptation Actions ................................................................................................ 31 Prioritisation of adaptation actions ..................................................................... 31

5

Recommendations ........................................................................................... 33

References .............................................................................................................. 36

1

Introduction

Future climate change poses significant risks to property and infrastructure through changes in temperature, rainfall and the increased occurrence or intensity of extreme weather events.

Understanding region-specific climate change projections provides an opportunity to assess these risks and develop management strategies and adaptation actions that reduce economic, environmental and social impacts associated with the asset.

Wagga Wagga is a major regional city in the Riverina region of NSW, which straddles the Murrumbidgee River and has an urban population of approximately 60,000. Climate change is projected to impact upon this area, leading to potentially unforeseen risks.

Wagga Wagga City Council (WWCC) manages many different assets in the local area which are at risk due to climate change impacts. A number of key asset classes were chosen by the Project Working Group (PWG) to undergo a risk assessment. The development of a Climate Change Risk Assessment & Adaptation Options Report (the Report) provides both operational and future recommendations that aim to ensure risks are managed appropriately, ensuring the climate resilience of these assets into the future.

Objectives The objectives of this Report were: 

Provide an understanding of localised climate change projections for the Wagga Wagga Local Government Area



Present a climate change risk analysis for the selected asset types



Develop a report outlining proposed adaptation actions

An example of the climate change projections visualised in map form is shown in Figure 1 below. It shows increase in days over 35oC in 2070 for NSW with Wagga Wagga’s increase indicated. Data is taken from NSW and ACT Regional Climate Modelling (NARCliM) Murray Murrumbidgee climate change snapshot (NSW OEH, 2017).

Figure 1 – Example of climate change projects – days over 35C 2070 (NARCliM)

Climate Change Risk Assessment & Adaptation Options for Council Assets

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WWCC aims to develop a robust, relevant and up to date climate adaptation options for the selected assets to manage the risks associated with future climate change related impacts. This report will be used to summarise the work done during the ‘Building Resilience to Climate Change’ project which received grant funding from Local Government NSW. A key part of the project was also to develop the Wagga Wagga Climate Vulnerability Explorer mapping tool which is hosted on WWCC’s Intramaps system.

2

Methodology

This Climate Change Risk Assessment & Adaptation Options Report) follows the ISO31000 Risk Management Process, and was designed to meet the requirements of the AS 5334 - Standard for climate change adaptation for settlements and infrastructure.

The risk assessment involved three key steps to develop risks and mitigation strategies collaboratively with key asset stakeholders. These steps are summarised below in Figure 2.

Climate and Context

Review of current risks

Review historic & best available climate projections

Multidisciplinary risk workshop

Review of asset operation and site location

Risk Analysis

Mitigation Strategies

Recommend design and operational mitigation strategies

Figure 2 – The collaborative climate change risk analysis process.

Background Research Initially, Edge assessed Wagga Wagga site information and location to understand potential vulnerability to any climate related risks. This stage involved building an understanding of historic weather events, and analysing scaled down climate change projections for the relevant geographic area. Due to the potential for significant impacts on infrastructure and property, the following climatic variables were of key interest for the Report: 

Extreme temperature



Rainfall (extreme precipitation and drought)



Flooding



Storm Intensity

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Project Description Wagga Wagga City Council (WWCC) manages a number of different assets in the local area. Key WWCC assets, as chosen by the Project Working Group (PWG), have been assessed for climate change risk and adaptation actions. The WWCC asset classes that were chosen align with Council’s series of Asset Management Plans and are detailed in the list below: 

Sewer Assets & Infrastructure



Stormwater Assets & Infrastructure



Transport Assets & Infrastructure



Recreational Assets & Infrastructure



Council Buildings & Businesses

Figure 3 below shows the output from the Wagga Wagga Climate Vulnerability Explorer mapping tool that was developed for this project. All the coloured shapes and points indicate the above listed WWCC assets. The Wagga Wagga Climate Vulnerability Explorer will be delivered in conjunction with this report and is an additional source of information on Council’s Intramaps system.

Figure 3 – Snapshot of Wagga Wagga Council Assets and Climate Change Risks

The Wagga Wagga Climate Vulnerability Explorer can be used to explore climate projections via an interactive map and historic weather data via interactive graphs for the Wagga Wagga area. Flood modelling, vegetation and social data is also visualised via the interactive map. For each of the assets the climate change risk workshop results are included as pop up information.

A list of the information provided in the Wagga Wagga Climate Vulnerability Explorer tool is as follows: 

Climate Projection – Increase in days over 35oC (2030, 2070)



Climate Projection – Increase in maximum temperature (2030, 2070)



Climate Projection – Water Stress (Current, 2030)



Modelling – 1 in 100-year flood, 1 in 20-year flood depth, 1 in 100-year flood depth



Climate Projection – Change in rainfall, Summer & Winter (2030, 2070)



Modelling – Urban Canopy



Modelling – Vegetation areas

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3



Climate Projection – Bushfire Risk increase (2030, 2070)



Modelling – Lone occupant households & low-income households



Zoning – Planning Zones



Historic data – Annual rainfall, daily rainfall, average rainfall



Historic data – Daily temperatures, heatwave days, solar exposure



Historic data – Wind speed and direction, severe storms by type

Climate Analysis Historic climate for Wagga Wagga

3.1.1

Temperature

The Wagga Wagga region has a temperate climate with hot dry summers and cool to cold winters.

Summer temperatures in Wagga Wagga are warm averaging between 29oC and 32oC with maximum recorded of 45.2oC. Relative humidity however remains low in the summer months with a 3pm average of about 30%. The winters are cool to cold with overnight minimums averaging 3oC and daily maximums climbing to only 12oC to 14oC on average. Relative humidity is much higher in winter with a 3pm average of over 60% and a 9pm average just below 90%. Frost and fog are a feature of Wagga Wagga in winter.

Snow has been recorded in the area but is a very rare occurrence. (BOM 2017).

Historical daily maximum and minimum temperatures for the region are displayed in Figure 4, with data from the Wagga Wagga AMO station (BOM ID: 072150). This station is close to the Wagga Wagga city centre (approximately 12.7 km), and has recorded weather data since 1941. The graphs below illustrate that annual maximum temperatures frequently exceed 35oC and 40oC (Figure 4).

Figure 4 – Daily Maximum and Minimum Temperatures – Wagga Wagga AMO Station

Heatwaves are defined as three or more consecutive days of hot weather over 35oC, and are of key concern due to their potential impacts upon infrastructure. Figure 5 below outlines the frequency of heatwaves at Wagga Wagga AMO for 1941-2017. Since 1941, on average there are 20.1 days above 35oC and 2.4 days above 40oC.

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Figure 5 | Historic Annual heatwave days (Number of days above 35C or 40C that are 3 or more consecutively) – Wagga Wagga AMO station

3.1.2

Rainfall

Average annual rainfall for Wagga Wagga is approximately 572 mm, distributed relatively equally over the full 12 months (BOM 2017).

The BOM rain gauge at Wagga Wagga AMO (BOM ID 072150) has been collecting rainfall data since 1941. The highest recorded daily rainfall at this site was 110.6 mm on March 8th 2010 (Figure 6). The average annual rainfall is shown in Figure 7 and shows the annual rainfall is quite variable for Wagga Wagga.

Figure 6 – Daily rainfall recordings at since 1941 show several large rainfall events – Wagga Wagga AMO station

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Figure 7 – Historic Annual Rainfall compared to Average Annual Rainfall – Wagga Wagga AMO station

3.1.3

Extreme weather events

Extremes of temperature and rainfall can have dramatic impacts upon infrastructure, and often occur during weather events that include storms, heat waves, droughts and bushfires. WWCC faces unique challenges related to extreme weather due to its scale, location and large variety of assets it manages.

The following climatic events have occurred in the project area and require consideration for the WWCC assets. 

Droughts: Droughts are relatively common in the Wagga Wagga Region. Most recently, the Millennium Drought caused over a decade of dry conditions and is considered one of the most severe droughts ever recorded in the region (BOM, 2017).



Floods: Since the first rural settlement in the early 1840s there have been 77 floods of over 8.23m. Official records of Murrumbidgee River heights since 1891 read at the Hampden Bridge gauge are available and estimated records are available of rivers over 8.23m since 1844. Flooding of the City area in the south flood plain was frequent and to a lesser extent flooding occurred in the North Wagga Wagga village. There have been years of frequent floods, i.e. in one year 1974 Wagga Wagga had five floods all over 8.92 m and there was severe flooding in the 1950 to 1956 period. In other long periods 1939 to 1949 and 1960 to 1970 no floods occurred. Significant floods have occurred in Wagga Wagga in 1852, 1853, 1870, 1891, 1925, 1950, 1952, 1974, 1991 and 2012 with the largest recorded flood of 10.97 metres occurring in 1844. There have been two floods greater than the 1974 flood (WWCC, 2017)



Bushfires: The Wagga Wagga region is also prone to Bushfires, with the most recent event being the 2006 Pulletop bushfire, which killed 2,500 sheep, 6 cattle and destroyed 2 hay sheds and 50km of fencing (NSWRFS, 2006).



Hail & Severe storms: The Wagga Wagga region is also prone to hail and severe storm events (See Figure 8 for the record of severe storm events in the last decade for the Wagga Wagga region (BOM, 2017)).

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Figure 8 – Annual Severe Storm Events for the Wagga Wagga region – (BOM Severe Storm Register, 2017)

Climate change projections Understanding future climate projections requires careful review of the most recent climate change emissions scenarios, and their related impacts on the climate system. Making use of scaled-down climate projections, it is possible to understand regionally-specific projections, which is more useful for conducting risk analyses on the built environment and infrastructure assets.

This study has been updated with the latest projections available from the CSIRO’s Murray Basin Cluster Report (CSIRO, 2015) and the NSW and ACT Regional Climate Modelling (NARCliM) Murray Murrumbidgee climate change snapshot (NSW OEH, 2017). CSIRO employed the Representative Concentration Pathways (RCP) emissions scenarios developed by the International Panel of Climate Change (IPCC) in their Fifth Assessment Report (AR5). These scenarios model climate change according to different economic growth, population, energy consumption and land use change trajectories over the next century.

The timescales selected for the NARCLiM and predominately used in this CAP are the following: 

1990 to 2009 (base),



2020 to 2039 (near future - 2030), and



2060 to 2079 (far future - 2070)

Analysis of projected climate changes involved summarising the key impacts that are likely to arise due to a changing climate. Temperature, rainfall and extreme weather events are of key concern due to their potentially significant impacts on the WWCC assets. Climate projections are described below, and are summarised in Table 2.

3.2.1

Average Temperature & Hot days

From NARCliM climate projections the number of days over 35°C are predicted to: 

increase by 9 days for 2030 and



increase by 24 days for 2070

The climate projections also predict that the average temperature will: 

increase by 0.6°C for 2030 and



increase by 1.9°C for 2070

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3.2.2

Rainfall

The NARCliM climate projections predict that the Summer (Dec-Feb) rainfall will: 

increase by 5.3mm for 2030 and



increase by 14.6 mm for 2070

Conversely the climate projections predict that Winter rainfall (Jun-Aug) will:

3.2.3



decrease by 0.8mm for 2030 and



decrease by 1.5mm for 2070

Extreme weather events

Future climate change is likely to increase the intensity and severity of extreme climatic events.

Importantly, the relationship between climatic averages and the frequency of extreme events is often non-linear, illustrated by climate projections that associate dramatic increases in very hot days with small increases in mean temperature (AGO 2006). This makes the development of reliable projections for extreme events such as storms and droughts very difficult. Key extreme climate projections are discussed in the following sections. 

Droughts: Droughts are a common feature of the South-East Australian climate, and are likely to continue to be so under a changing climate. However, there is low confidence in predicting changes in the frequency and longevity of extreme droughts in the future. There is medium confidence that under a high emissions scenario, the Murray Basin region is likely to experience increased time under drought conditions (CSIRO 2015).



Storms and extreme rainfall: There is high confidence that the intensity of rainfall will increase under a changing climate but, as with mean rainfall projections, the scale of these changes is difficult to predict (CSIRO 2015).



Fire weather: From NARCliM projections, Bushfire risk via the Forest Fire Danger Index is predicted to increase by 0.5 by 2030 and increase by 0.98 by 2070.

Table 2 – Wagga Wagga Climate Change projections, Key climate variables (2030 and 2070) compared to annual averages Baseline Variable (1990-2009) Temperature – average annual

Near Future

Far Future

(2030)

(2070)

+ 0.7oC

+ 2.0oC

+9

+ 24

Units

22.2oC

o

C

References

(NSW OEH, 2017)

maximum Temperature – Hot Days Rainfall – Annual mean

Extreme rainfall

Bushfire Risk Index

Average days 20.1

over 35oC per

(NSW OEH, 2017)

year 572.6 mm

mm

NA

NA

10

Danger Index

Summer: +5.3mm Winter: -0.8mm

Summer: +14.6mm Winter: -1.5mm

High confidence in increased intensity of rainfall under both scenarios, however magnitude of this change is uncertain.

(NSW OEH, 2017) CSIRO (2015)

Forest Fire + 0.5

+ 0.98

(NSW OEH, 2017)

(FFDI)

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4

Risk Assessment & Adaptation Actions Risk Workshop

Climate change risks to Wagga Wagga City Council and their associated adaptation actions were identified through a workshop held on the 31st of July 2017. Workshop attendees included stakeholders representing a multidisciplinary skill set across Council. The attendees of the workshop are listed in Table 3.

Table 3 – Project Working Group Workshop attendees Name

Company

Michael Gleeson

Wagga Wagga City Council – Parks Operations

David Read

Wagga Wagga City Council - Environment

Lisa Saffery

Wagga Wagga City Council – Social Planning

Alice Kent

Wagga Wagga City Council - Environment

Glenda Pym

Wagga Wagga City Council – Recreation Planning

Jason Carroll

Wagga Wagga City Council - Environment

Stephen Jewell

Wagga Wagga City Council – Water Operations

Chris Breen

Wagga Wagga City Council – Water Operations

Joel Clayton

Edge Environment

Jessica Lethbridge

Edge Environment

Ken Lunty

Edge Environment

4.1.1

Workshop

The workshop presentation established the context of climate change and its potential impacts on the Wagga Wagga Local Government Area (LGA). It introduced project stakeholders to climate change projection scenarios, and encouraged them to consider climate change impacts in the context of their LGA. Risks resulting from these impacts were then developed and recorded, considering both direct and indirect risks to WWCC LGA, its assets, users and any other relevant stakeholders. Each risk was then evaluated and rated in terms of likelihood and consequence using the risk matrix presented in Table 4 and Table 5.

4.1.2

Risk Assessment Framework

To assess identified risks systematically, a likelihood scale was used to determine how likely a risk was to occur, followed by a consequence assessment. These scales are aligned with established risk assessment criteria. Likelihood ratings are described for event risks in Table 4.

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Table 4 - Example Likelihood Scales (AGO 2007).

Rating

Description

Quantification

Almost certain

The event is expected to occur in normal circumstances. There has been frequent history

At least once every 1-6 months

Likely

The event will probably occur in most circumstances. Some recurring past event history

Once every 6-12 months

Possible

The event could occur sometimes.

Some past warning signs or previous event history

Once every 1-5 years

Unlikely

The event could occur in some circumstances

Once every 5-10 years

Rare

May only occur in exceptional circumstances

Once every 10 years or more

4.1.3

Consequence

Consequence is an assessment of the severity of the risk’s impacts should it occur. Consequence assessment included several success categories in line with the WWCC risk assessment criteria (Table 5 over page).

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Table 5 - WWCC Consequence Scale

Financial

Governance

Community and Reputational

Strategic

Environmental

Operational

Health & safety

Severe impact to staff availability

Catastrophic

Significant/ material financial loss over $1 million

Significant regulatory breach/s including court proceedings

Widespread total degradation of operations and services Extreme adverse public/staff reaction and/or major widespread negative publicity

The project will completely stop Delivery of objectives cannot be achieved

Significant environmental impact, EPA intervention including significant fines

Significant procurement impact/loss, including serious breach of probity Widespread systems / records management outage declared for an extended period beyond the Maximum Acceptable Outage time

Kill or cause permanent disability or ill health

Major impact to staff availability

Major

Moderate

Major financial loss of $100,000 to $1 million

High financial loss of $50,000 to $100,000

Significant regulatory breach/s

Moderate regulatory breach

Major degradation of services and operations.

Major adverse public/staff reaction and/or significant negative publicity

Moderate degradation of services and operations Moderate adverse public/staff reaction

Climate Change Risk & Adaptation Action Plan - Wagga Wagga

Key parts of project will be delayed more than a month Major impact that threatens delivery of objectives

Key parts of the project will be delayed more than a week

Major environmental impact, EPA intervention

Major impact/loss resulting from procurement processes, including breach of probity

Long term illness or serious injury

Loss of system access or access to records for an extensive period Moderate environmental impact handled internally

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Moderate impact to staff availability

Medical attention and several days off work

Financial

Governance

Community and Reputational

Strategic

and/or moderate negative publicity

Moderate impact to agreed delivery of objectives

Environmental

Operational

Health & safety

Moderate impact/loss resulting from procurement processes Loss of system access or access to records for a prolonged period

Minor

Minor financial loss of Operations $5,000 to $50,000

Minor degradation of services and operations.

Minor regulatory breach

Capital $10,000 to $50,000

Insignificant

Low financial loss of up to: Operations $5,000 Capital $10,000

Minor adverse public/staff reaction and/or minor negative publicity

No degradation of services.

No regulatory breach

No adverse public/staff reaction and/or negative publicity

Climate Change Risk & Adaptation Action Plan - Wagga Wagga

Minor impact to staff availability Some delay anticipated to project delivery Minor impact to agreed delivery of objectives

A very small delay anticipated to project delivery Negligible impact to agreed delivery of objectives

Minimal environmental impact handled internally

Minor impact/loss resulting from procurement processes

First aid treatment needed

Minor impacts resulting from loss of system access or access to records Negligible impact to staff availability

No environmental impact

Insignificant impact/loss resulting from procurement processes Insignificant impacts results from system interruptions

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No injury to persons

Risk assessment matrix Risk likelihood and consequence were then combined using the risk assessment matrix in Table 6, leading to the systematic development of a risk rating used to prioritise risk management strategies.

Table 6 - Risk Assessment Matrix (AGO 2007)

Insignificant

Minor

Moderate

Major

Catastrophic

Almost Certain

Medium

Medium

High

Extreme

Extreme

Likely

Low

Medium

High

High

Extreme

Possible

Low

Medium

Medium

High

High

Unlikely

Low

Low

Medium

Medium

Medium

Rare

Low

Low

Low

Low

Medium

4.2.1

Risk Assessment outcomes

The following table describes the risks identified in the workshop, including the risk statement (outlining the risk’s cause and effect), the asset the risk may impact, its likelihood, consequence and subsequent risk rating, should it occur. Results of the stakeholder review are also incorporated, providing the adaptation actions and revised risk level. Risks that were identified as ‘LOW’ to begin with were not included, nor were any that did not have a viable adaptation option identified by the PWG.

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SEWER ASSETS & INFRASTRUCTURE Climate Impacts

Risk Statement (Cause and Effect)

Likelihood

Consequence

Level of Risk

Increased rainfall variability

SEW1- Increased rainfall variability and increased intensity of storm events leads to fluctuating volumes of water to deal with causing difficulty in maintaining treatment processes resulting in increased costs for electricity and chemicals

Residual Likelihood

Residual Consequence

Level of Risk

3-Possible

1-Insignificant

Low

2-Unlikely

3-Moderate

Medium

3-Possible

2-Minor

Medium

Implement a targeted inflow and infiltration prevention program to minimise increase in volume of water in sewer network from rainfall events 3-Possible

3-Moderate

Medium

Develop a program of indoor demand management activities to reduce load on sewer network

Identify energy efficiency measures for assets

Increased intensity of storm events

Increased intensity of storm events

Adaptation Actions

Install permanent generator or alternate off-grid option for each pump site

SEW2- Increased storm events leads to black outs causing pumping failure and sewer overflows resulting in public health issues, environmental harm and possible fines

3-Possible

SEW3- Increased hot days leads to odour issues which leads to impacts on the community resulting in complaints from community and possible fines

4-Likely

4-Major

High Evaluate the adequacy of emergency storage capacity at each treatment plant

2-Minor

Medium

Investigate feasibility of oxygen injection and odour control methods

Increase in hot days

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SEWER ASSETS & INFRASTRUCTURE

Climate Impacts

Increased flooding

Increased bushfire risk

Risk Statement (Cause and Effect)

SEW4- Increased flooding leads to inundation of vulnerable infrastructure, causing system failure resulting in public health issues, environmental harm, repair costs and possible fines

SEW5- Increase in bushfire risk leads to damage of critical infrastructure, causing system failure resulting in public health issues, environmental harm, repair costs and possible fines

Likelihood

Consequence

Level of Risk

Adaptation Actions

Residual Likelihood

Residual Consequence

Level of Risk

2-Unlikely

4-Major

Medium

1-Rare

4-Major

Low

Identify specific flood prone assets and evaluate site specific opportunities to move or protect asset 3-Possible

4-Major

High Implement actions from the Floodplain Risk Management Plan and the Sewer Asset Management Plan

2-Unlikely

Climate Change Risk Assessment & Adaptation Options for Council Assets

5-Catastrophic

Medium

Identify specific bushfire prone assets and evaluate site specific opportunities to move or protect asset

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STORMWATER ASSETS & INFRASTRUCTURE Climate Impacts

Increased intensity of storm events

Risk Statement (Cause and Effect)

STM1- Increased flooding and increased storm events leads to overflow of capacity causing localised flooding resulting in decreased access, community complaints and increased maintenance and renewal costs

Likelihood

Consequence

Level of Risk

Adaptation Actions

Residual Likelihood

Residual Consequence

Level of Risk

2-Unlikely

3-Moderate

Medium

Implement actions from the Floodplain Risk Management Plan and the Stormwater Asset Management Plan

3-Possible

Increased flooding

Climate Change Risk Assessment & Adaptation Options for Council Assets

4-Major

High

Review modelling and design requirements to allow for greater flow volumes

Review and upgrade capacity of pumps as needed

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TRANSPORT ASSETS & INFRASTRUCTURE Climate Impacts

Risk Statement (Cause and Effect)

Likelihood

Consequence

Level of Risk

Residual Likelihood

Residual Consequence

Level of Risk

4-Likely

2-Minor

Medium

3-Possible

3-Moderate

Medium

Increase urban canopy along shared pathways

Increase in hot days TRN1- Increase in hot days and increase in average temperature leads to urban heat island effect causing public health issues and decreased use of facilities

5-Almost

3-Moderate

High

Certain

Increase shading at bus stops and car parks

Implement relevant actions from the Active Travel Plan and Street Tree Strategy

Increase in average temperature

Increase in hot days

Adaptation Actions

TRN2- Increase in hot days and increase in average temperature leads to fatigue and degradation of materials and surfaces resulting in increased cost of maintenance and renewals

4-Likely

4-Major

High

Utilise materials and designs for pavements and surfaces that are highly resistant to high temperatures

Increase in average temperature

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TRANSPORT ASSETS & INFRASTRUCTURE

Climate Impacts

Risk Statement (Cause and Effect)

Likelihood

Consequence

Level of Risk

Adaptation Actions

Residual Likelihood

Residual Consequence

Level of Risk

3-Possible

2-Minor

Medium

Implement actions from the Floodplain Risk Management Plan and the Transport Asset Management Plan Increased intensity of storm events

TRN3- Increased intensity of storm events and increased flooding leads to decreased access, degradation of materials and surfaces resulting in increased cost of maintenance and renewals

4-Likely

Increased flooding

Climate Change Risk Assessment & Adaptation Options for Council Assets

4-Major

High

Utilise materials and designs for pavements that are highly resistant to inundation

Retain flood paths in new developments

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RECREATIONAL ASSETS & INFRASTRUCTURE Climate Impacts

Risk Statement (Cause and Effect)

Likelihood

Consequence

Level of Risk

Increase in hot days

Increase in hot days

REC1- Increase in hot days leads to public health concerns causing decreased use of facilities and cancellation of events

REC2- Increase in hot days and increase in rainfall variability leads to plant stress and decreased amenity resulting in increased costs for additional watering and plant replacements

5-Almost Certain

3-Moderate

High

Adaptation Actions

Implement relevant actions from the Recreation Open Space Community Strategy to increase shading at playgrounds, sportsgrounds and parks

Residual Likelihood

Residual Consequence

Level of Risk

3-Possible

3-Moderate

Medium

3-Possible

2-Minor

Medium

Develop a Heatwave Management Plan

Install water efficient irrigation systems 5-Almost Certain

3-Moderate

High Ensure plant selection is appropriate for hotter, drier conditions

Increased rainfall variability

Climate Change Risk Assessment & Adaptation Options for Council Assets

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RECREATIONAL ASSETS & INFRASTRUCTURE Climate Impacts

Risk Statement (Cause and Effect)

Likelihood

Consequence

Level of Risk

Adaptation Actions

Residual Likelihood

Residual Consequence

Level of Risk

3-Possible

2-Minor

Medium

3-Possible

2-Minor

Medium

Install water efficient irrigation systems as per the irrigation audit Increase in hot days

REC3- Increase in hot days and increase in average temperature leads to degradation of playing surfaces, causing decreased satisfaction and use of facilities resulting in increased cost of maintenance and renewals

5-Almost

3-Moderate

High

Investigate diversifying water sources to include stormwater, greywater or blackwater

Increase in average temperature

Increased intensity of storm events

REC4- Increased intensity of storm events and increased flooding leads to fatigue and degradation of materials and surfaces resulting in increased cost of maintenance and renewals

Install tolerant or synthetic turfs

Certain

Implement actions from the Floodplain Risk Management Plan and the Recreation Asset Management Plan 3-Possible

3-Moderate

Medium Utilise materials and designs for built recreational assets that are highly resistant to high temperatures and frequent inundation

Increased flooding

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RECREATIONAL ASSETS & INFRASTRUCTURE

Climate Impacts

Risk Statement (Cause and Effect)

Likelihood

Consequence

Level of Risk

Adaptation Actions

Residual Likelihood

Residual Consequence

Level of Risk

4-Likely

3-Moderate

High

Implement site specific Plans of Management Increased rainfall variability

REC5- Increase in rainfall variability and increase in average temperature and leads to increased algal growth and low water levels in recreational water bodies resulting in decreased use, decreased amenity and community complaints

Divert stormwater where feasible 5-Almost Certain

3-Moderate

High Investigate options for de-silting, use of treated effluent and algal control measures

Increase in average temperature

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COUNCIL BUILDINGS & BUSINESSES Climate Impacts

Risk Statement (Cause and Effect)

Likelihood

Consequence

Level of Risk

Increase in hot days

Increase in hot days

BLD1- Increase in hot days leads to animal welfare issues at the LMC causing animal deaths resulting in economic impacts and reputational damage

3-Possible

3-Moderate

Medium

BLD2- Increase in hot days leads to operational issues for the Airport causing service delays resulting in economic impacts and reputational damage

3- Possible

4-Major

High

Residual Consequence

Level of Risk

Investigate options for increasing shade and water infrastructure

2- Unlikely

2-Minor

Low

Utilise materials and designs that are highly resistant to high temperature

2-Unlikely

2-Minor

Low

4-Likely

2-Minor

Medium

Identify and implement energy efficiency initiatives at Council buildings

Increase in hot days BLD3- Increase in hot days and increase in average temperature leads to increased use of airconditioning resulting in increased electricity costs at Council facilities

Residual Likelihood

Adaptation Actions

5-Almost Certain

Increase in average temperature

Climate Change Risk Assessment & Adaptation Options for Council Assets

3-Moderate

High Investigate feasibility of passive cooling projects such as green roofs and heat reflective surfaces

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COUNCIL BUILDINGS & BUSINESSES

Climate Impacts

Risk Statement (Cause and Effect)

Likelihood

Consequence

Level of Risk

Increased intensity of storm events

BLD4- Increase in intensity of storm events and increase in flooding leads to decreased access, service delays and damage to buildings resulting in increased maintenance and renewal costs

Adaptation Actions

Residual Likelihood

Residual Consequence

Level of Risk

3-Possible

3-Moderate

Medium

4-Likely

2-Minor

Medium

Implement actions from the Floodplain Risk Management Plan and the Buildings Asset Management Plan 3-Possible

4-Major

High Modify design and construction of future assets for increased Probable Maximum Flood levels

Increased flooding

Increased bushfire risk BLD5- Increase in bushfire risk and increase in flooding leads to increased cost of insurance premiums

5-Almost

3-Moderate

High

Undertake site specific risk assessments to identify vulnerable assets and evaluate options to move or protect asset

Certain Modify design and construction of future assets for increased Bushfire Attack Levels

Increased flooding

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Risk Summary and Evaluation A total of thirty-eight climate change related risks to assets were identified in the risk workshop and presented to WWCC PWG. Only 31 of these were progressed through to this report and an adaptation action provided. These risks are associated with several common climate variables. An increase in hot days generated the most risks in the analysis, and were dominated by the following impacts: pumping failures, infrastructure and vegetation damage, and an impact on public health and services.

Increased rainfall variability, increased intensity of storm events and increased flooding also pose a high number of risks and impacts relating to maintaining STP processes, aquatic health, increased reliance on irrigation and sewer and detention basin overflows. Increase in average temperature and increased bushfire risk both have a number of similar impacts. The variables and key impact areas for Wagga Wagga City Council are summarised in Table 8 below.

Table 8 – Climate variables and their key climate impacts.

Climate variable

Number of risks

Focus impact areas Blackouts and pumping failures

Increase in hot days

9

Public health impacts Infrastructure damage Biodiversity and vegetation damage Issues maintaining STP process conditions

Increased rainfall variability

3

Aquatic health issues i.e. algal growth, drought Increased reliance on irrigation Reduced use of facilities, loss of income

Increased intensity of storm events

Blackouts and pumping failures

6

Sewer overflows Overflowing of detention basins

Increased flooding

6

Erosion or silting of lake Infrastructure damage Public health impacts

Increased average temperature

Increase in weed/pest species Increase in plant stress

2

Critical infrastructure damage Increased insurance premiums

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Adaptation Actions Post-workshop evaluation with participants generated adaptation actions for each risk through asset changes or operational management. The key aim was to reduce the risk rating by suggesting strategies that could remove the risk or reduce its impacts.

The list of revised risks was then circulated through the workshop participants, who verified the adaptation measures and revised the risk ratings. The final risk counts are identified in Figure 9 below.

Through this method, sixteen high risks were reduced fourteen medium risks and one low risk level, and three medium level risks were reduced to a low level of risk.

Figure 9 – Comparison of risk before and after proposed adaptation actions

Comparison of risk before and after adaptation actions 18 16 14 12 10

HIGH

MED Before

LOW

After

Prioritisation of adaptation actions To assist with developing an action plan that prioritises the adaptation actions for implementation, each adaptation action was given a priority rating score. The rating score was based on four factors; initial risk rating, asset renewal date, cost and practicality to implement. See the following for the prioritisation categories and weighted scoring.

Table 9 - Scoring factors for priority rating

Level of Risk

Asset Renewal Date

Cost ($) Indication to implement Action

Practicality of Action

Low

Short term - Up to 5 years

Low: $0-$50,000

Simple: Minimal project management and procurement process

Medium

Medium term - 5 to 10 years

Medium: $50,000 $500,000

Moderate: Some complexity, requires RFQ and >40hours of Project Management

High

Long term - More than 10 years

High: >$500,000

Complex: requires tender and dedicated project manager

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Each adaptation action was given a score individually from 1 to 4 for each of the four factors; initial risk rating, asset renewal date, cost and practicality to implement (see Table 10). Each of the four factors are weighted differently to give a final score to determine the total priority score.

The total priority score is then sorted into band ranges to give an overall priority rating (Table 11). The higher the score, the higher the priority rating.

2

Short term Up to 5 years

3

1

Low: $0$50,000

3

1.5

Simple

3

1

Medium

2

2

Medium term - 5 to 10 years

2

1

Medium: $50,000 $500,000

2

1.5

Moderate

2

1

High

3

2

Long term More than 10 years

1

1

High: >$500,000

1

1.5

High

1

1

Extreme

4

2

Score

1

Score

Low

Score

Weight

Practicality of Action

Score

Cost ($) Indication to implement Action

Weight

Asset Renewal Date

Weight

Level of Risk

Weight

Table 10 - Four factors score and weighting

Table 11 - Min - Max score range for priorities

Min range score

Max range score

Priority Rating

5.5

9.8

Low Priority - Implement when funding is available

9.8

14.2

Medium Priority- Implement with next renewal

14.2

18.5

High priority - Implement ASAP

The WWCC Risk and Adaptation Action spreadsheet has been provided to Wagga Wagga City Council.

Worksheet ‘AA Prioritisation’ includes drop down boxes that allow you to change the factors and the scores for each adaptation, and will automatically change the priority rating accordingly.

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5

Recommendations

This section of the Report sets out the prioritised adaptation actions for Wagga Wagga City Council to successfully mitigate and manage the risks identified through the risk analysis process. Many of the actions require planning, costing and strategic placement into asset renewal and operational plans to ensure risks are managed appropriately.

Table 12 below sets out the risks, their relevant adaptation actions, and priority rating given for implementation and management of these risks. The priorities, derived from the method outlined in section 4.5 above are as follows: 

High priority - Implement ASAP



Medium priority- Implement with next renewal



Low priority - Implement when funding is available

Table 12 - Summary of adaptation actions required to achieve revised risk rating

Risk

Risk Rating Before/After

Adaptation Actions

Priority to Implement

TRN1

High-Medium

Increase urban canopy along shared pathways

High

Install water efficient irrigation systems REC1

REC2

High-Medium

High-Medium

High

Ensure plant selection is appropriate for hotter, drier conditions Implement relevant actions from the Recreation Open Space Community Strategy to increase shading at playgrounds, sportsgrounds and parks

High

Develop a Heatwave Management Plan Install permanent generator or alternate offgrid option for each pump site SEW2

High-Medium

SEW3

High-Medium

Evaluate the adequacy of emergency storage capacity at each treatment plant

Investigate feasibility of oxygen injection and odour control methods

Medium

Medium

Identify specific flood prone assets and evaluate site specific opportunities to move or protect asset SEW4

Medium

High-Medium Implement actions from the Floodplain Risk Management Plan and the Sewer Asset Management Plan Risk Rating

Priority to Risk

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Risk

Risk Rating Before/After

Priority to Implement

Adaptation Actions Implement actions from the Floodplain Risk Management Plan and the Stormwater Asset Management Plan

STM1

High-Medium

Review modelling and design requirements to allow for greater flow volumes

Medium

Review and upgrade capacity of pumps as needed

TRN2

High-Medium

Utilise materials and designs for pavements and surfaces that are highly resistant to high temperatures

Medium

Implement actions from the Floodplain Risk Management Plan and the Transport Asset Management Plan

TRN3

High-Medium

Utilise materials and designs for pavements that are highly resistant to inundation

Medium

Retain flood paths in new developments Install water efficient irrigation systems as per the irrigation audit REC3

High-Medium

Medium

Install tolerant or synthetic turfs Investigate diversifying water sources to include stormwater, greywater or blackwater

REC4

High-Medium

Implement actions from the Floodplain Risk Management Plan and the Recreation Asset Management Plan

Medium

Utilise materials and designs for built recreational assets that are highly resistant to high temperatures and frequent inundation

BLD3

High-Medium

Identify and implement energy efficiency initiatives at Council buildings Medium Investigate feasibility of passive cooling projects such as green roofs and heat reflective surfaces Implement actions from the Floodplain Risk Management Plan and the Buildings Asset Management Plan

BLD4

High-Medium

Medium Modify design and construction of future assets for increased Probable Maximum Flood levels

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Risk

BLD5

Risk Rating Before/After

High-Medium

Priority to Implement

Adaptation Actions

Undertake site specific risk assessments to identify vulnerable assets and evaluate options to move or protect asset

Medium

Modify design and construction of future assets for increased Bushfire Attack Levels Implement site specific Plans of Management REC5

High-High

Divert stormwater where feasible

Medium

Investigate options for de-silting, use of treated effluent and algal control measures BLD1

Medium-Low

Investigate options for increasing shade and water infrastructure

Medium

Implement a targeted inflow and infiltration prevention program to minimise increase in volume of water in sewer network from rainfall events SEW1

Medium-Low

Medium

Develop a program of indoor demand management activities to reduce load on sewer network Identify energy efficiency measures for assets

SEW5

Medium-Low

BLD2

High-Low

Identify specific bushfire prone assets and evaluate site specific opportunities to move or protect assets

Low

Utilise materials and designs that are highly resistant to high temperature

Low

It is recommended that Council incorporate priority actions into their Integrated Planning and Reporting processes, and ensure that an updated analysis of risks is undertaken on a regular basis in line with Council’s Risk Management Framework.

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References AGO (2006). Climate Change Impacts and Risk Management - A Guide for Business and Government. Canberra: Australian Greenhouse Office - Commonweath of Australia.

Bewsher Consulting. (2010). Macquarie Park Floodplain Risk Management Study & Plan. City of Ryde.

Bradstock, R., Davies, I., Price, O., & Cary, G. (2008). Effects of climate change on bushfire threats to biodiversity, ecosystem processes and people in the Sydney region. New South Wales Department of Environment and Climate Change.

CSIRO. (2015). East Coast Cluster Report, Climate change in Australia Projections for Australia's Natural Resource Management Regions. CSIRO and Mureau of Meterology.

IPCC. (2007). Climate Change 2007: Synthesis Report. International Panel on Climate Change.

National Climate Change Adaptation Research Facility (NCCARF). (2010). Case study: Impacts and adaptation responses of infrastructure and communities to heatwaves. NCCARF. NSW OEH. (2014). Metropolitan Sydney Climate Change Snapshot. Sydney: Office of Environment and Heritage.

NSW OEH. (2014). New South Wales Climate Change Snapshot. Sydney: NSW Office of Environment and Heritage.

NSW OEH. (2017, June 14). AdaptNSW. Retrieved from About NARCLiM: http://climatechange.environment.nsw.gov.au/Climate-projections-for-NSW/About-NARCliM NSWRFS. (2006). Bushfire Bulletin (vol28 No.01). Retrieved from NSW Rural Fire Service: http://www.rfs.nsw.gov.au/ data/assets/pdf_file/0009/4122/Bush-Fire-Bulletin-2006-Vol-28No-1.pdf Schuster, S. S., Blong, R. J., Leigh, R. J., & McAneney, J. K. (2005). Characteristics of the 14 April 1999 Sydney hailstorm based on. Natural Hazards and Earth System Science, 5, 613-20. van Dijk, A. I., Beck, H., Crosbie, R. S., de jeu, R. A., Liu, Y., Podger, G., & Timbal, B. V. (2013). The Millennium Drought in southeast Australia (2001–2009): Natural and human causes and implications for water resources, ecosystems, economy, and society. Water Resources Research, 1040-1057.

WaterNSW. (2017, 06 09). Water Supply Historical Timeline. Retrieved from WaterNSW: http://www.waternsw.com.au/supply/Greater-Sydney/heritage/timeline

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