Sadly, millions of people locate in high flood areas. Especially those poorer folks who do not have finances to decide.
Even during normal thunderstorms roads get flooded over ankle depth....not good when getting off jeepneys etc.
So much of NCR is below sea level level and close to river levels....
Here in Marikina so many millions have been used but still there is flooding always during rainy season...it'll never get fixed IMHO
Most of Quezon City gets flooded.
Actually we do have some regrets about our relocation here and have a strategy to move away in a year or two.
For a huge city the opportunities are somewhat limited....
As always, those who can least protect themselves take the biggest hits year on year on year