Nowhere for the water to go: Dubai flooding shows the world is failing a big climate change drainage test

The Dubai flooding last week illustrated how urban engineering is failing a major climate change test. In a world marked by the increasing possibility of extreme weather events, no matter how big and modern expanding urban environments around the globe get, they don't have enough places for all the water to go when there's too much of it. 

The United Arab Emirates' city and others like it built on previously uninhabitable areas reflect 20th century urban development ideas that result in the blocking of natural water absorption systems. Add increased populations, bringing with them more waste — and more need for landfills and other waste disposal methods — and the drainage challenge will continue to bedevil major global cities like Dubai facing more frequent, massive rainfalls.

Last Tuesday, the UAE received more than 10 inches of rainfall in some places, and roughly half of that level in Dubai, amounts equal to annual rainfall averages in the UAE. More frequent rain in recent years in the UAE is expected to get even worse in the years ahead, in particular, intense daily rainfall accumulations. Claims were made last week that experiments the UAE has been conducting with cloud seeding contributed to the rainfall, but the government told CNBC that was inaccurate, and other experts have dismissed those claims.

What's known is that Dubai was built on sand, a natural environment which lets water seep into the soil very easily. But by pouring massive amounts of concrete on top of Dubai's natural terrain, the developers effectively blocked the soil from absorbing water. Last week's rainfall was the largest amount of precipitation recorded since the country began keeping tabs in 1949. 

"We have natural drain places that bring water