I remember the post-Harvey statistics... the average payout by insurance to homeowners who had flood insurance was something like $140,000. The average payout by FEMA to homeowners without flood insurance was around $4,000.
As for flooding during this big storms...
https://www.houstonchronicle.com/news/article/In-Harvey-s-deluge-most-damaged-homes-were-12794820.php
Some highlights from the article...
"The new data supports those concerns. More than half of the homes damaged by Harvey were outside all flood plain designations, meaning that such building rules, had they been in place during Harvey, still would have fallen short of protecting more than 100,000 Harris County homes.
Along Interstate 69 south of the Galleria, a few blocks in the Uptown neighborhood have flooded every year for the past three, yet they still aren’t considered part of the flood plain."
"More than half of the structures damaged during the Tax Day floods in 2016 were outside the 100-year flood plain, similar to the pattern during Harvey."
"More than a third of structures damaged during the Memorial Day floods in 2015 were outside the 100-year flood plain, similar to the pattern during Harvey."
"“Not in a flood plain? So they say,” Blanton said. “But every time it rains we get flooded the heck out. Last time, I put my wife on the roof. I put my daughter on the roof. I put four dogs on the roof.”