Disaster Risk Reduction & Adaptation��International River Symposium�September 2025

Introduction

• Director, UPRS – Urban Places, Regional Spaces
• 16+ yrs’ private and public sector in Australia/Pacific
• 2 x National Emergency Medal
• Floodplain Management Australia Technical Director
• Engineers Australia Water Panel Committee
• Planning and Environment Court Expert

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Disaster Risk Reduction

Sendai Framework for Disaster Risk Reduction

• Vision:

The substantial reduction of disaster risk and losses in lives, livelihoods and health and in the economic, physical, social, cultural and environmental assets of persons, businesses, communities and countries.

• Goal:

Prevent new and reduce existing disaster risk through the implementation of integrated and inclusive economic, structural, legal, social, health, cultural, educational, environmental, technological, political and institutional measures that prevent and reduce hazard exposure and vulnerability to disaster, increase preparedness for response and recovery, and thus strengthen resilience.

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What is the benefit

• Flood and storm are the most likely natural disasters

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Source: The Human Cost of Weather Related Disasters (1995-2015)

What is the benefit

• Flood and storm are the most likely natural disasters
• Exposure to flood risk means prevention is not viable long term

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What is the benefit

• Flood and storm are the most likely natural disasters
• Exposure to flood risk means prevention is not viable long term
• Internationally:
• “Substantially increase the availability of and access to multi-hazard early warning systems and disaster risk information and assessments to the people by 2030.”
• Effective flood forecasting, warning and alerts can help reduce flood damage by up to 35%
• Average annual damage by flooding reduced by 5%

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Flood risk management

Integrated Flood Risk Management

• Involves:
• Data collection
• Flood study
• Flood risk management study
• Flood risk management plan
• Plan Implementation

Risk Management

• Risk considers:
• Exposure
• Likelihood
• Vulnerability
• Tolerability
• Risk-based standards:
• Framework
• Principles
• Process

Source: ISO31000, SAI Global

Risk Management

• Risk = likelihood x consequence

Flood risk factors

• Flood exposure varies across the floodplain, generally:
• Deeper, faster more frequent near the waterway
• Very rare, to extremely rare likelihood the further (and higher) you move away
• Consider the consequence of flooding to different uses

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Understanding the risk picture

• Flood levels

Understanding the risk picture

• Flood levels
• Flood depth

Understanding the risk picture

• Flood levels
• Flood depth
• Events > 1%AEP

Understanding the risk picture

• Flood levels
• Flood depth
• Events > 1%AEP
• Flood hazard

Understanding the risk picture

• Flood levels
• Flood depth
• Events > 1%AEP
• Flood hazard
• Time to inundation

Understanding the risk picture

• Flood levels
• Flood depth
• Events > 1%AEP
• Flood hazard
• Time to inundation
• Duration of inundation

Understanding the risk picture

• Flood levels
• Flood depth
• Events > 1%AEP
• Flood hazard
• Time to inundation
• Duration of inundation
• Flood islands

Understanding the risk picture

• Flood levels
• Flood depth
• Events > 1%AEP
• Flood hazard
• Time to inundation
• Duration of inundation
• Flood islands
• Vulnerability and infrastructure

Legacy risk

• Homes and buildings have a lifespan of ~70yrs
• Communities last longer…
• We need to consider the risk, not just today but over that lifetime.
• Insurance is reaching its capacity to received transferred residual risk

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Disaster risk reduction and adaptation

Features of Disaster Risk Reduction

• Establish a Framework
• Identifies priorities
• Identifies principles
• Goals
• Outlines strategies/actions

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Features of good practice Disaster Risk Reduction

• What does good practice look like:
• Integrated, adaptable planning
• Clear governance
• Good data = good exposure understanding
• Understand community vulnerability
• Assess infrastructure/asset tolerability
• Agreed funding pathways focus on prevention
• Continuous improvement

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Every $ invested on prevention saves between $4 and $7 in recovery

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Features of good practice Disaster Risk Reduction

• What can we do:
• Evacuation infrastructure
• Warning Systems
• Social infrastructure and cohesion
• Community awareness and preparedness

Source: State Disaster Mitigation Plan

Total Flood Warning Systems

• A warning system is a means of getting information about an impending emergency, communicating that information to those who need it, and facilitating good decisions and timely response by people in danger.

Total Flood Warning Systems

• Protective behaviour is the goal
• Key elements
• Message construction
• Review
• Communication and feedback

Total Flood Warning Systems

• Monitoring and Prediction
• Manual observations
• Telemetry
• Meteorologic inputs

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Flood Warnings Spectrum of Forecasting

Total Flood Warning Systems

• Interpretation
• Manual
• Automated
• Success is measured based on ability for at-risk community to react/enact

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Total Flood Warning Systems

• Message Construction
• Simple
• Timely
• Link risk to action
• Interoperable – multi-modal

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Total Flood Warning Systems

• Communication:
• Pros and cons of different flood warning communication methods

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Using the transect to adapt and reduce disaster risk

Upper catchment:

• Steeper
• Limited warning
• Fast rate of rise
• Short duration of inundation

Lower catchment:

• Wide, flatter (deltas)
• Longer warning
• Slower rate of rise
• Longer duration of inundation
• Influence of ocean levels

Mid catchment:

• Wider
• Moderate warning
• Can be “flash” flooding
• Moderate duration of inundation

Using the transect to adapt and reduce disaster risk

Features of good practice Disaster Risk Reduction

• What can we do:
• Evacuation infrastructure
• Warning Systems
• Social infrastructure and cohesion
• Community awareness and preparedness

Source: State Disaster Mitigation Plan

Thank you

William Prentice

0431 161 282

william@uprs.com.au

www.uprs.com.au