Before flood mitigation was installed Houston rarely flooded. After flood mitigation was installed Houston flooded even less. Now Houston, even with flood mitigation, is flooding. So what has changed?
A lot of what has changed is more development happening. Pavement doesn't absorb water all that well. When the flood mitigation talked about in this article was put in place the area they chose to flood to handle overflow was undeveloped and so was all of the surrounding area.
"Pervious concrete was first used in the 1800s in Europe as pavement surfacing and load bearing walls.[3] Cost efficiency was the main motive due to a decreased amount of cement.[3] It became popular again in the 1920s for two storey homes in Scotland and England. It became increasingly viable in Europe after WWII due to the scarcity of cement. It did not become as popular in the US until the 1970s"