When Hurricane Sandy struck the east coast of the US in October 2012, railways, airports, and roads were flooded, and transportation ground to a halt.
However, in an era of climate change, the massive storm and the damage it caused wasn’t an aberration – nine of the costliest mainland US hurricanes have occurred in the past 15 years.
In Australia, flooding across New South Wales and Queensland in February and March 2022 also caused significant infrastructure breakdown. Some sources forecast that repairs to roads, including bridges and freeways, damaged by landslips, fallen trees and potholes will cost as much as $1 billion.
In Lismore – which experienced two inundations a month apart – one of the town’s two sewerage plants suffered damage during the floods. As a result, in the wake of the floods, authorities were forced to release four megalitres of untreated sewage into Wilsons River each day, contaminating waterways and causing the NSW Environmental Protection Agency to issue a “do not use” warning for water in the area.
The earth’s surface has already warmed roughly 1.2[CW1] °C since the beginning of the industrial age and is heating up by just under 0.2°C per decade. According to the CSIRO, in Australia we will see hotter temperatures, reduced cool-season rainfall, longer fire seasons, and more heatwaves, droughts and intense, short-duration heavy rainfall events due to climate change – all of which will impact the nation’s infrastructure.
Design and adaptation
Mark Gibbs, a specialist in coastal climate adaptation, says the threat the effects of climate change pose to infrastructure is twofold. “When you put more energy and more moisture in the atmosphere, everything gets more variable. So, droughts are worse, and floods are potentially more intensive as well – that’s one side of the equation,” he says. “The other side of the equation is we continue to put more value at risk – we continue to economically intensify the catchments and coastal regions.”
Climate resilience starts with design. In Australia, says Gibbs, we have a “terrible habit” of designing poorly ventilated buildings reliant on air-conditioning and ill-suited to Australian conditions.
Driving these poor design choices is a desire to reduce purchase prices without considering the long-term costs of heating and cooling. “Nobody ever really considers the operational cost, which is increasing all the time,” says Gibbs.
Applying a whole-of-life approach – taking into consideration rising energy prices – would result in different design choices and more climate-resilient assets, he says.
When it comes to existing assets, one school of thought favours relocating major infrastructure such as sewerage treatment plants or constructing bunds to offer protection from extreme weather events – both are costly approaches.
In Australia, says Gibbs, we’ve come to embrace a different strategy, one of adaptation. This approach asks how to adapt those assets to occasional flooding, rather than investing in expensive relocation or construction of new infrastructure.
“Our thinking around adaptation has matured a lot over the last decade,” says Gibbs. “Initially, where we had people saying, ‘Just move a power plant,’ we’re now saying, ‘That’s not really an option. Let’s think about how we can adapt it to occasional nuisance flooding.’”
This policy of adaptation has been seen in Queensland, which has experienced a series of devastating floods in recent years. “Seqwater did a lot of work after the 2011 floods, such as moving critical electricity infrastructure higher up,” says Gibbs. AC and other electrical systems typically found in the basement of high-rise buildings are now being installed on higher floors. “If a flood occurs you just get the cars out and let the basement car parks flood, because there’s no critical infrastructure in there.”
The key to successful adaptation is the ability to bring infrastructure back online quickly. In the 2011 floods in Queensland “we had inundation that lasted for days, but those assets were out for months and months”, says Gibbs. “Whereas if you can live with the inundation for a couple of days but bring assets back online and back up to service levels within days afterwards, that’s a huge gain.”
[CW1]Averaged across land and ocean, the 2020 surface temperature was … 1.19˚C warmer than the pre-industrial period (1880-1900).