The Dubai floods show the world is failing a major drainage test on climate change – NBC Chicago

• The flooding in the United Arab Emirates city of Dubai last week illustrates a simple climate change problem that the modern world has not yet solved: lack of drainage.
• New cities built in previously uninhabitable areas block natural water absorption systems, and older cities are not immune to the problem either, as rainfall occurs more frequently and massively.
• “If we pave asphalt, it will no longer be there,” said a sustainability expert about a major challenge in urban development and climate engineering for the future.

Last week’s Dubai flood illustrated how urban construction is failing to meet a major test in climate change. In a world characterized by the increasing possibility of extreme weather events, no matter how large and modern the growing urban environments around the world become, they don’t have enough places for all the water to go if there is too much of it.

The United Arab Emirates city and similar cities built on previously uninhabitable areas reflect 20th century urban development ideas that result in the blocking of natural water absorption systems. Add to that an increased population, which brings more waste – and a greater need for landfills and other waste disposal methods – and the drainage challenge will continue to plague major global cities like Dubai, which experience more frequent, massive rainfall.

Last Tuesday, the UAE received more than 25 centimeters of rain in some places, and roughly half that level in Dubai, matching annual rainfall averages in the UAE. The more frequent rainfall seen in recent years in the UAE is expected to worsen in the coming years. Last week it was claimed that experiments the UAE conducted with cloud seeding contributed to the rainfall, but the government told CNBC this was inaccurate, and other experts have dismissed the claims.

What is known is that Dubai is built on sand, a natural environment where water can easily seep into the ground. But by pouring huge amounts of concrete onto Dubai’s natural terrain, developers effectively prevented the ground from absorbing water. Last week’s rainfall was the largest amount of precipitation since the country began keeping records in 1949.

“We have natural drainage points that bring water directly to the aquifers and then to our water supplies,” says architect Ana Arsky, CEO of environmental startup 4 Habitos Para Mudar o Mundo. “If we pave it, it won’t be there anymore,” Arsky said.

The rapid rise of population groups associated with global urbanization trends contributes to the waste, and while waste is not visible on the streets of Dubai, it has to go somewhere and often ends up in less than ideal locations. Plastic products do not absorb water well, and when they end up in landfills around the world, huge piles of waste contribute to a global backup of natural drainage systems.

Even older cities with established drainage systems face similar problems, as residents of New York City discovered last fall, with schools, roads and homes flooded, and subway and rail service halted after single-day rainfall in some places between was 15 and 20 centimeters. . Without proper preparations, man-made drains full of debris and pollution cannot absorb the increased water, leading to backups and flooding.

“Stormwater drainage systems are not adapted to the flows we are currently seeing due to climate change and extremely concentrated rainfall,” said Tiago Marques, co-founder and CEO of Greenmetrics.AI. “You get a saturation of the drainage system that cannot in any way drain the amounts of water that have fallen recently. This eventually rises to the surface and causes urban flooding, whether you’re talking about tunnels, highways or the lowest parts of the city.”

Greenmetrics.AI installs sensors and uses data analytics to predict the impact of rainfall and help advise communities on water consumption, and is currently working with civil authorities in six cities in Portugal.

Marques said citizens tend to blame municipal officials when flooding occurs because they don’t properly clean drainage systems, but in Porto, Portugal, there were severe floods in several parts of the city last year and drainage systems had been cleaned. “The amount of water was so high and so unusual that all the branches and even trash went into the drainage systems that were previously clean, blocking them,” Marques said. “When all this water starts piling up, it’s very difficult for authorities to know exactly what’s happening everywhere at the same time.”

Greenmetrics places smart sensors with LIDAR – the same technology used to power self-driving cars – in areas vulnerable to flooding to warn if levels become too high to control. Combined with a better understanding of weather patterns, authorities can clear drains and debris before flooding hits. In cases where flooding is unavoidable, the technology can give people time to evacuate or give leaders time to close sites to minimize casualties.

“What you used to have every 100 years … is starting to happen every 10 years,” Marques said. “Then the floods that now occur once every decade start happening every few years. Adapting to climate change means building resilient technologies.”

Vapar, a startup that builds sewage disposal and pipe inspection robots to spot problems before big storms hit, is working with governments in Australia and Britain

Arsky’s 4 Habitos Para Mudar o Mundo helps companies including AB-InBev and Brazil’s Banco Itaú bank, as well as consumers, categorize waste using artificial intelligence so it can be dumped in the right areas to reduce its impact on the environment. minimize runoff. The company is also working to develop building materials that are strong enough for structures, but porous enough to ensure that water is still absorbed by the area’s natural soils.

Arsky said the more frequent flooding in the world’s most densely populated areas is yet another reminder of the underlying message sent to the world by events like the Dubai flood: “Climate change has no specific address.”