Flood risk in the world: the investments to avoid urban flooding

Venice under water. Days of incessant rains added to the reckless dredging of canals to accommodate massive cruise ships and an inadequate infrastructure system are placing one of humanity’s most cherished cities at risk.

But today's damage is nothing compared to the dangers of tomorrow. The World Resource Institute (WRI), a prestigious non-profit foundation based in Washington DC, has created a world map showing flood risk trends for the next 100 years. The map shows water levels in Venice in the next decade will be much higher than they are now. By 2030 the cost of urban flooding in Italy could reach $6.5 billion, while Italy’s GDP could fall by almost $1 billion annually due to damage from weather disasters, says the WRI.

The flooding in Venice, which was covered by mass media around the world, is only the most recent example of damage caused by a climate gone mad. Venice shows that damage can affect not only the economy and people’s lives, but also humanity’s historic and artistic heritage.
Many other countries besides Italy are exposed to flood risk, which is destined to grow in the years to come.
The danger is widespread. The Aqueduct Global Flood Analyzer, the site created by WRI with Amsterdam University and Utrecht University to monitor flood risk, says that 21 million people are affected annually by floods, a number that could increase to 54 million in 2030.

Urban flooding: rivers carry the most risk

Most of the floods due to weather events concern rivers, and mainly affect cities. Everyone remembers when the Seine flooded in January 2018, and the world held its breath as it watched to see if the river would breach its banks and flood Paris.
That did not happen. But cities around the world flood each year, and some countries are more at risk than others. According to the Aqueduct Global Flood Analyzer, 80% of the people affected by the phenomenon are concentrated in 15 countries. Leading the ranking is India with 4.8 million people who risk being hit by a flood each year; followed by Bangladesh (3.4 million people), China (3.2 million) and Vietnam (900,000 people).

These atmospheric phenomena have a direct impact on the economies where they happen. In Venice, the damage has exceeded €1 billion, according to early estimates, and confirms how destructive these floods can be. New York City also knows something about this. Hurricane Sandy caused billions in damages in 2012, forcing even the Wall Street Stock Exchange to close for two days.
India has the highest percentage of GDP exposed to flooding each year, at $14.3 billion, and could grow to as much as $154 billion in the next 30 years. The economic cost of climate change is very high. According to the Aqueduct Global Flood Analyzer, it also affects developed economies. In 2030, European countries including Croatia, Finland, Portugal, Ireland and other developed countries such as Australia and Israel will begin to appear on the list of at-risk countries.
Ireland is an emblematic case. Some 2,000 people there face flood risks today, and that number could rise to 48,500 in 2030.

Infrastructure to protect us from water

If on the one hand the fight against climate change and international pressure to adopt a sustainable development model are now on the political agenda of many governments, on the other the quickest and safest response to these changes is to adopt modern infrastructures able to protect goods and people from violent weather.

After hurricane Sandy hit New York City hard, Bill de Blasio's city administration set up the "Lower Manhattan Climate Resilience Study" to gauge climate effects. The results were dramatic. According to the research, without infrastructure changes, by 2050 37% of the properties in Lower Manhattan will be at risk, while in 2100 the amount at risk will reach 50% of the total, and 20% of the roads will be subjected to a daily flood danger.
On the basis of this analysis, the city administration has launched $500 million plan for the safety of the Hudson River and the East River coasts, an area which produces 10% of the city's GDP and where 10% of New York City jobs are concentrated.
New York City is not alone. In Pittsburgh, more rain has fallen than ever over the last year, causing water levels in the city’s three major rivers the Allegheny, Monongahela and Ohio, to rise alarmingly. To avoid the risk of flooding, the Pittsburgh Water and Sewer Authority allocated $201 million in 2018 to upgrade the city's water network.
In Washington D.C., the Clean Rivers Project is a $ 2.7 billion project in which Salini Impregilo is participating and which involves the construction of a tunnel system to manage the wastewater of the rivers in the US capital.
Over in Europe, London is threatened by the floods of the Thames (50 in 2018 alone) and has launched an ambitious infrastructure project. The work, which is still in progress, involves building a 25-kilometre (15-mile) underground tunnel to carry wastewater and stormwater from heavy rains. The Thames Tideway Tunnel will cost €4.7 billion and should be finished in 2023.

New York, London and Pittsburgh all show that infrastructure projects are needed, especially in large cities. As reported by "We Build Value" in the article "Climate change threatens megacities" the problem is widespread. The OECD estimates that $6.3 trillion is needed annually from 2016 to 2030 to keep pace with development and the impact of climate change. The C40 (the international group representing the 40 largest cities in the world) found that 9 megacities out of 10 are already reporting problems related to climate change. In the battle with a climate gone mad, infrastructure has become an effective protection against a risk no one seems to be taking seriously enough.