The techniques in the article will mitigate the effects of storm water. As was the case in Houston, urban flooding results from global weather events. No matter how Houston had been planned, all the water had to go somewhere and it was going to the low spots. The only counter-factual in which Houston would not have had some flooding is if there was no Houston.

Ancient cities in Mesopotamia flooded. Ancient Rome flooded. Cities flood because they are built on or near bodies of water and bodies of water flood. The reason cities are built on or near bodies of water: water is a necessary condition for any city. Water is also an economic engine: fisheries, agriculture, waste removal, transport, trade. This makes flooding a price of doing business.

It's not that mitigation is a bad idea. The bad idea is that a city will never flood. Though it is theoretically possible, it is practically unlikely.