I'm in Waller county, this is the kind of rain we had on a freak night a couple of years ago. It came in sheets ...all night long. It absolutely matters about the rate. But that's to a certain point. 30" over a week is totally different than over a couple days...but....Houston isn't geared for this kind of runoff in either case.
And the new rain band for me has just arrived. It's wailing outside. Rain gauge is telling me closet 4" per hour. In a couple of hours, I'll be in my underwear evacuating chickens from chest high water just like before. Hopefully the other livestock are smart enough to seek high ground.