Dubai under water. The dramatic images show one thing: an efficient sewage system is essential to weather the rain. With global warming, torrential rains are expected to become more and more frequent throughout the world.
The extremes will become more extreme, that is the watchword often repeated by scientific experts, when they talk about weather events and the impact that global warming has on them. The city of Dubai recently suffered from extreme weather conditions: 254 millimeters of rain fell in one day in the United Arab Emirates. This is the equivalent of what has fallen in almost two years and a historic record.
Highways and airports under water, houses flooded, the spectacular images quickly went around the world. The problem is that there are no or very few sewers… Given the little rain that there usually is, the water that falls from the sky normally evaporates from the streets. Where there is no tar, sand absorbs water quickly. But one of the problems here is that the tar actually prevents the water from reaching the sand.
Cities are not ready for these rains
These torrential rains may be an extreme example, but it shows that cities today are not always ready to handle heavy rains. Especially cities which were thus built on a former uninhabitable area, like a desert. They have no place to drain all this water, or even the means to transport it there.
But it’s not just these cities built in the middle of the desert that are affected, reports CNBC. This is also the case in regions where it rains more often and where cities are equipped with water evacuation systems. In New York for example, last year in the fall, schools and roads were flooded and subways and trains had to be stopped. This is because the sewers are often full of waste and are therefore quickly blocked when it rains a lot in a short time. Same observation in Paris, in summer 2023, where even metro stations were under water after storms.
AI to the rescue
And this is also the case when the sewers are cleaned regularly. This took place last year in Porto, Portugal. “The amount of water was so large and unusual that it washed all the branches and even trash into the previously clean sewer systems and blocked them. When all this water starts to accumulate, it is very difficult for authorities to know exactly what is happening everywhere at the same time,” Tiago Marques, CEO of Greemetrics.AI, explains to CNBC. This is a company that uses sensors and data analysis to manage the condition of sewers and rainwater drainage and works with municipalities in Portugal. With live weather data, it allows cities to prepare for rain but also to warn and evacuate residents when water levels rise.
“Rainwater drainage systems are not adapted to the flows we are currently seeing with climate change and extremely concentrated precipitation. You get a saturation of the system, which has no way of evacuating the quantities of water that have fallen. This eventually rises to the surface and causes urban flooding, whether tunnels, highways or the lowest parts of the city,” he reflects more broadly. “What used to happen every 100 years starts happening every 10 years. Floods that used to occur every ten years are starting to occur every two years. Adapting to climate change requires implementing resilience technologies.”
