There are several areas around town that have homes with a history of flooding. Think areas along Braes Bayou and Buffalo Bayou. Many of the houses are in areas that make the area very desirable for many homeowners to live in. These areas have desirable churches, schools, access to the medical center, etc.
Some of these homeowners have just had enough flooding and are selling their homes. Others are raising the entire house and slab foundation to a higher elevation making it far less likely that the house will floor again.
Raising an existing slab foundation is possible and is an option for some. Below is a video by the leader in this field: Du-West Services.
Bear in mind that the process converts a ground-supported foundation into an elevated foundation. This can be done with the assistance of a Texas Professional Engineer. (I am not interested in this work.)