Protecting Airports From Flood Risk

As low-lying airports recognize the risks associated with climate change and rising sea levels, it is critical that they begin to build resilience.

Major storms, including accompanying winds and floods, threaten lives, destroy property and damage critical infrastructure. Power outages, broken communication lines and disruption to road, rail, sea and air transport are common in the aftermath of major storms. Among the damages from September’s Hurricane Florence, for example, was the closure of 200 roads in South Carolina, including a section of Interstate 95 – a major highway connecting the U.S.’s East Coast. South Carolina officials estimated that the storm caused more than $300 million in infrastructure damage.

On the other side of the globe, Typhoon Jebi caused widespread damage throughout Japan, and flooding closed an airport. As storms and rising sea levels increase flood risk, governments around the world are looking for ways to better protect people and communities. In addition to devastating societies, over the past few decades floods have led to $550 billion in global economic impact.

While we cannot fully protect ourselves from flood, working across industries is critical to build resilient communities and protect critical infrastructure. With many of the world’s busiest airports at a low elevation – and many more built near water on reclaimed land – these hubs are prime examples of infrastructure in need of protection. Not surprisingly, airport operators are rising to the challenge.

In Depth

September’s Typhoon Jebi shut down Kansai International Airport in Japan’s Osaka Bay. The airport, built on a manmade island and handling almost 30 million passengers a year, suffered considerable damage. A storm surge breached a seawall and flooded a runway and terminal building, leaving thousands of passengers and staff stranded. Kansai, a major international hub that serves several cities (including Kobe, Kyoto and Osaka), was closed for 10 days; and it took a further week to restore regular operations. Complicating the situation was the fact that critical facilities, such as the disaster response center and an electrical substation, were located in a terminal basement and flooded.

See also: Flood Risk: Question Is Where, Not When

Airports are critical elements of our infrastructure and, consequently, their resilience is essential. As the Airports Council International (ACI) noted in a September policy brief focused on airports’ resilience and their adaptation to climate change, “As an essential service provider to a wide range of stakeholders and users, the airport infrastructure and operations must have high levels of availability, reliability and resilience.”

Reclaimed Land, Rising Seas, Sinking Airports

Kansai is not the only major airport built on reclaimed land. Australia’s Brisbane Airport is on coastal reclaimed land, and San Francisco International Airport’s reclaimed site is gradually sinking. Other airports are at risk simply because their low elevation puts them at risk of a storm surge. A recent report from the U.S. National Climate Assessment identified 13 of the country’s 47 busiest airports as having at least one runway within 12 feet of current sea levels.

If sea levels continue to rise, these hubs will face increased exposure to storm surge risk. In general, the hydrological importance of airports: runways, halls and other facilities create large areas of impermeable surface with zero infiltration capacity. During extremely intensive rainfalls, which are increasing in strength due to climate change, airports can become extremely prone to pluvial, or flash, flooding. This can add to the pressure on airport management to revisit how effective their flood protection really is, especially as some structures are decades old.

Addressing the Risks and Protecting Critical Assets 

As structures face risks posed by severe weather and other potential shocks, protecting infrastructure means developing resilience. Greg Lowe, global head, sustainability and resilience, at Aon, underscores the importance of properly safeguarding these critical assets – especially in the context of climate-related risk. Looking at infrastructure long-term, he states, is crucial, and “cities are asking whether their infrastructure is fit for purpose over decades.”

In the case of airports, the ACI’s September 2018 policy brief warned that more extreme weather “may lead to fundamental transformation of the socio-economic system.” For airports, “the risks of flooding, flight disruptions and cancellations become more likely.”

“Airports need to understand the risks and initiate adaptation measures for both existing and new infrastructure, as well as managing critical operations to become more resilient to the changing climate,” according to the ACI brief. The ACI brief also encourages airport operators to examine all the potential impacts of extreme weather on their facilities so they can prioritize and respond to the risks.

“Only comprehensive climate-change risk-management strategies will ensure the continuity of operation, profitability and asset value,” the brief said.

Gary Moran, head of aviation Asia at Aon, echoes the ACI’s advice and thinks many airport operators are taking it to heart. “We are seeing more consideration to protect against flood damage and planning around storm drains around airports so that they are fit for purpose.”

How Airports Are Increasing Resilience

As the exposures worsen, various airports are addressing their flood risks. San Francisco airport officials have installed seawalls and are looking to take other steps to protect the airport, including a potential $383 million project that would include measures to help the facility defend itself against further rises in sea level by 2025.

See also: Top Emerging Risks for Insurers  

Boston’s Logan International Airport has set a goal of becoming a national model for resilience planning and implementation among port authorities. Risk mitigation steps undertaken so far include purchasing temporary flood barriers, raising electrical and mechanical equipment above forecasted flood levels, sealing and waterproofing openings and conduits, installing water sensors and pumps and installing systems to anchor temporary flood fences and flood barriers in emergencies.

Meanwhile, Changi Airport in Singapore has resurfaced its runways to provide better drainage and is building a terminal at a higher level to protect against flooding as sea levels rise. Brisbane Airport officials also are building higher, with a new runway built a meter higher than originally planned. Meanwhile a higher seawall and better drainage to address higher sea levels are also being planned.

Building Storm Resilience

Airports are a critical part of our modern infrastructure, essential to linking people and businesses around the world. Events that disrupt activities at a major airport can have a significant economic impact. As low-lying airports recognize the risks associated with climate change and rising sea levels, it is critical that they begin to build resilience to storm surges and flooding. As they do so, they may well provide lessons to officials elsewhere who are looking to protect other forms of vital infrastructure from storms and other natural perils.

This article originally appeared on Aon’s The One Brief.

Peter Puncochar

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Peter Puncochar

Petr Punčochář is head of flood model development at Impact Forecasting, EMEA, APAC – Reinsurance Solutions, Aon. He is responsible for the impact forecasting flood models and their development in all territories, except the U.S.

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