I assume they're basing it off a compilation of data or just talking to large developments. 

It's an excellent compilation to help a newbie like myself get a basic understanding of the sheriff's sale process.Ken

I’m compiling a list of my repairs and a list of everything that needs to be done.

But I'd suggest that the real answer is:(d) All of the above.I don't think you need to spend days or weeks compiling an exhaustive buyers list.  

Are there publicly available records of things like flood depth by address that you used to compile this database?

If you'd like some friendly help id gladly put in some time as I already have most of them compiled as a hobby/research.

@Jack D Falkner if you use the driving for dollars app then it will compile all of the properties into a list for you then you can mail to the list.

@Harjot GillAt this link, you can find all the info you ever need to know re foreclosure auctions as so graciously compiled by @Steve Babiakhttps://www.biggerpockets.com/forums/41/topics/689...Happy reading!

(on a list compiled by the FBI) and is currently noted as an area to avoid by SmarterTravel.com. 

If I'm not mistaken, I believe the plan is to eventually run a new rail (Blue) through Third Ward, too.FYI, in case you didn't know, a few years ago Third Ward Houston was ranked the 15th most dangerous neighborhood in the US on a list compiled by the FBI.