Some councils still rely on outdated paper maps as supercharged storms make flood planning a mockery

Entire towns are apparently locked in more frequent and severe flooding. Status quo development continues despite extreme weather and sea level rise due to climate change. While some local councils have online mapping, others still use outdated paper maps.

Repeated flooding in eastern Australia has prompted the Planning Institute of Australia to call for a framework to update flood mapping to take climate change into account.

A flood map shows areas to be flooded based on hazard modeling and past weather data. In addition to identifying risk areas for land use planning, these maps are needed for flood responses. The problem with static flood maps is that they don’t show the critical details of the hazard a flood will present.

Paper flood maps such as this excerpt from the 1982 Lower Hawkesbury Floodplain Atlas do not include critical details such as water depth, velocity, rate of elevation and isolation potential.
Author provided

Councils have a duty to provide flood maps that accurately identify areas at risk, as well as those that are safe. Yet existing information on river and coastal flood risk was “patchy and outdated”, the institute said.

[…] there is a patchwork of data sets collected and inconsistently applied by councils and water authorities, who often do not have the budgets to pay for the necessary modeling, or the political authority to apply controls to the local level. This means that new housing and developments can occur in areas prone to flooding […]

For many flooded communities, the immediate priority is to deal with the emergency. However, we must not lose sight of how urban planning has affected them, nor the urgent need for planning frameworks to catch up with the impacts of climate change.

Read more: ‘Do you want lunch? Can I clean the chook’s house? : what flood survivors really need after a disaster

Who is responsible ?

The floods highlighted the glacial pace of climate change adaptation planning frameworks at all levels of government.

For example, the New South Wales government’s Floodland Directive that came into effect in July 2021 still adheres to the principles of the state’s Floodplain Development Handbook of 2005, which advocates development in flood plains.

Dysfunctional relationships between different levels of government also persist. Victoria Premier Dan Andrews said flood mapping was primarily “a matter of local government”. New South Wales Premier Dominic Perrottet has led the nature versus people debate by announcing that the wall of the Warragamba Dam, the tallest in Sydney, will be raised.

Those on the front lines of the floods see things differently. The mayor of Wollondilly, south-west of Sydney, said:

Raising the Warragamba Dam is not in the best interests of Western Sydney, potentially costing over $2 billion and allowing developers to cover rural floodplains with housing, as well as the opportunity to create a sense of complacency among those still at risk of catastrophic flooding.

Cover of the report A Supercharged Climate
This Climate Council report from March 2022 drew attention to the changes that planners have to deal with.
Australian Climate Council, CC BY

The National Climate Change Resilience and Adaptation Strategy, based on a 2012 report by the Council of Australian Government (COAG), outlines the adaptation roles and responsibilities of the three levels of government. The strategy states: “Local governments are at the forefront of dealing with the impacts of climate change.

Local councils are therefore considered to have a crucial role in adaptation at the local level. But how can underfunded councils deal with the ongoing damage to infrastructure and the legacy of development in areas affected by supercharged weather systems?

It’s a legacy that has led to $7 billion in insurance claims from floods, storms and cyclones over the past 18 months.

Read more: ‘A Clever Plan’: How La Niña releases squads of storm clouds to wreak havoc in your area

The politics of flood mapping

The issue of flood mapping is complicated by a level of political entrenchment related to property rights. Councils fear they will antagonize voters and taxpayers who see their assets devalued by a flood rating. When the Gold Coast Council released updated flood maps in 2018, for example, they caused a stir among residents.

On the central coast of New South Wales, the local council carried out a flood study which concluded that the majority of housing lots would be flooded due to rising sea levels in the coming decades . Yet the council removed the option to retire or buy back property under pressure from residents. They preferred adaptations such as levees, walls, and raising their buildings. Boards should obtain additional funds to cover the costs of these measures.

On the other hand, the community opposed a planned levee at Seymour, due to concerns about loss of views, access and habitat on the river. This led to the local council abandoning the levee to protect homes and businesses which have now been flooded.

aerial view of flooded city
In Seymour, community opposition led the council to scrap a seawall planned to protect the town in 2020.
Diego Fedele/AAP

Read more: Wild La Niña weather could wipe out huge stretches of Australian beaches and sand dunes

You have to plan for the long term

Current approaches to flood mitigation are not a viable long-term strategy. More development in floodplains means more property damage when floods occur. The increase in population also puts additional pressure on emergency services and evacuation routes.

Even before the latest floods, the Insurance Council of Australia released a statement, Building a More Resilient Australia, which said:

“[…] it is imperative that governments at the state and federal level commit to dramatically increasing investment in programs to mitigate the impact of future events. We also need to plan better so that we no longer build houses in danger. [and] make buildings more resistant to the impacts of extreme weather conditions”.

If the insurance industry gets it, why are governments still allowing new developments in high-risk areas? Some consider that the development of these areas is necessary to solve the current affordable housing crisis. Others see it as linked to development industry lobbying. And some councils want the revenue from tariffs and fear costly lawsuits for denied development applications.

So, to the big question: how do governments address climate risk from flooding and urban development in planning frameworks? Regional and state plans take a long time to draft, submit to public consultation, reformulate and be approved.

Read more: ‘Building too close to water. It’s ridiculous!’ Flood buyout talks show climate adaptation needs to be taken seriously

A new era calls for a new approach

Climate change presents thorny issues for communities, governments and urban planning. As ice caps melt, sea levels rise, and climatic factors change, more extreme weather increasingly threatens the fabric of our society.

Planning frameworks must adapt to the climate crisis. This requires land use approaches that move people and property away from dangerous floodplains. As the Planning Institute of Australia warned:

“The decisions planners make now have a lasting impact, and our profession is essential in responding to a changing climate. »

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