Dubai's flooding highlights the world's struggle with climate change drainage solutions.

• The flooding in Dubai last week highlights a straightforward climate change issue that the contemporary world has not resolved: inadequate drainage.
• New urban development in previously undeveloped areas disrupts natural water absorption systems, while older cities also face challenges with increased rainfall frequency and intensity.
• A sustainability expert stated that once we pave, the issue disappears, posing a significant urban development and climate engineering challenge for the future.

Despite the growing prevalence of extreme weather events, expanding urban environments worldwide are unable to accommodate the excess water during heavy rainfall.

Dubai, like other cities built on previously uninhabitable areas, reflects 20th century urban development ideas that hinder natural water absorption systems. As populations grow and produce more waste, the challenge of managing drainage intensifies, particularly for cities like Dubai that face more frequent and intense rainfall.

Last Tuesday, the UAE experienced more than 10 inches of rainfall in some areas, with Dubai receiving roughly half of that amount. This rainfall was equivalent to the annual rainfall averages in the UAE. Recent years have seen an increase in rainfall frequency in the UAE, which is expected to worsen in the future. While some have claimed that cloud seeding experiments conducted by the UAE contributed to the rainfall, the government has denied this, and other experts have dismissed these claims.

Since Dubai was constructed on sand, a naturally permeable environment, water easily seeps into the soil. However, by laying concrete over Dubai's natural landscape, developers inadvertently obstructed the soil's ability to absorb water. As a result, last week's rainfall, the largest recorded since 1949, caused flooding in the city.

"Natural drainage areas directly transport water to our water reserves, but when we pave, they disappear," said Ana Arsky, CEO of environmental startup 4 Habitos Para Mudar o Mundo.

The increase in population due to urbanization worldwide results in more waste, and although Dubai's streets do not show visible trash, it often ends up in undesirable locations. Plastic products do not absorb water well, and when they accumulate in landfills globally, they contribute to a backlog of natural drainage systems.

Despite having established drainage systems, cities are still facing flooding issues, as seen in New York City last fall when heavy rainfall caused flooded schools, roads, and homes, and halted subway and railroad service. Without proper maintenance and preparation, manmade drains filled with debris and pollution can't handle the increased water, resulting in backups and flooding.

"According to Tiago Marques, co-founder and CEO of Greenmetrics.AI, rainwater drainage systems are not designed to handle the current flows brought about by climate change and extreme rainfall concentration. As a result, drainage systems become saturated and cannot handle the large amounts of water that have been falling recently. This leads to urban flooding, whether it occurs in tunnels, highways, or the lowest parts of the city."

Greenmetrics.AI utilizes sensors and data analytics to forecast the effects of rainfall and provides recommendations to communities on water usage, and is currently collaborating with civil authorities in six cities in Portugal.

In Porto, Portugal, despite citizens often blaming municipal officials for not properly cleaning drainage systems during flooding, the city experienced serious flooding last year and the drainage systems had been cleaned. However, the amount of water was so high and unusual that it swept all the branches and trash into the previously clean drainage systems, blocking them. This made it difficult for authorities to know exactly what was happening everywhere at the same time during the flooding.

Greenmetrics utilizes LIDAR sensors, the same technology employed in self-driving cars, to monitor flood-prone areas and alert authorities when water levels become unmanageable. By combining this data with improved weather forecasting, authorities can proactively clear drains and debris before flooding occurs. In instances where flooding is unavoidable, LIDAR sensors can provide valuable time for individuals to evacuate or for leaders to shut down operations to minimize damage and casualties.

"Every 100 years, floods would occur, but now they happen every 10 years. As climate change progresses, these floods are becoming more frequent, occurring every couple of years. To adapt to this change, we need to build resilience technologies."

Governments in Australia and the U.K. have partnered with Vapar, a startup that constructs sewer drain and pipe-inspecting robots to detect problems before severe storms occur.

Arsky's 4 Habitos Para Mudar o Mundo helps companies and consumers categorize waste with the help of artificial intelligence, minimizing its impact on drainage. Additionally, Arsky is working on developing building materials that are strong enough for structures but porous enough to allow water to be absorbed by the area's natural soils.

The increasing frequency of flooding in densely populated areas, as seen in Dubai, underscores the message conveyed by climate change: "No specific address exists for climate change."