Harris County flood official on KHOU says in the SE part of the county flooding is so bad that residents are climbing into their attics to escape the water. Water is too high to effect rescues in some areas plus there are many, many calls for help.
My mother grew up in Meraux, SE of New Orleans. She said, with total seriousness, they kept a couple of axes in their attic.
The entire Houston metroplex just experienced 45 minutes of heavy rain. These current bands will clear past, but a new very nasty one will soon follow.