I live on the coast in Houston--well, Deer Park, but no one knows where in the hay that is, and as I type I hear the splash of rain, AGAIN.
We are used to a good amount of rain, 55" or so a year, the last several years have been less due to a S/W wind disposition.
Our drainage system will generally hold up to rains such as yesterday, when it takes 5/6 hours to get the 8 inches we had. generally we can expect big gulps two or three times a year, 6/7 inches overnight or over a day.
It is the 12/15 inches or more in two or three hours that cause the problem. just two miles from my home, Pasadena got 11 inches last night and had some minor flooding concerns, IF flooding is to be considered minor.
Just the lay of the land boys.
Blessings