This is really useful, thanks for the post

Hi, I'm a FEMA point of contact on this.

Shape files can be found here:

http://www.gismaps.fema.gov/2005pages/rsdrkatrina.shtm

The older ones likely reflect how much assessment has been done rather than how much flooding occurred at that point in time.

We should have this page cleaned up with updates in the next few days. We will continue to provide Google with updates.

Regards,
-Scott

Scott, and everybody here, just an FYI.

This data is NOT accurate to the degree that we're used to here. The flooding overlay in particular is provably off by several blocks in some cases.

The good news is that it seems to be consistently erring on the side of 'flooded', so it's doubtful that somebody looking at this would be given false hope that their home had survived.

Basically, I wouldn't use this overlay to answer peoples' questions about exactly what's going on on the ground in any more than general terms. I suppose that's true of all the imagery we look at, but just keep in mind that this overlay seems to have quite a bit of fudge factor.

That being said, I should also point out that it's entirely possible, if not probable, that the guys at NGA and FEMA intentionally introduced a margin zone, because of that inherent uncertainty of 'ground truth', and I both understand and approve that, if that's the case. This post was not in any way meant to take away from the work they're doing, but rather to point out that we are not the data consumers that this information was prepared for, but rather we are also being allowed to look at it, and this is just not what we're used to (or maybe it's just me, who knows).

I only brought it up at all because my initial reaction after a week of piecing together floodlines was to think to myself that the flooding had gotten worse somehow, despite the fact that reports are saying that the water is receding.

Actually I had heard this morning that it had gotten worse, though like you, I assumed the flooding had started receding as well.

Maybe NOAA is right-on with this informatiom though your explanation of a 'fudge factor' would let them CYA

This is very helpful... thanks!

Will you be updating it as FEMA releases new data? I noticed there's a Sep 6 one up already...

Thanks!

-CityCoop

I was working on it as you were typing. The main file has been updated, now working on the 2nd (non clamped filled poly version).

Thank you Scott, and the many others that are making this information available. I'm very glad to hear of the possibility of updates.

I've heard from all over that seeing this kind of information is very helpful to people. I'm working with the local Red Cross shelter to give evacuees access to this data through Google Earth. It's nice to know that even us computer desk potatoes can do something.

Thanks for that link! This is very valuable information.
I've been looking all over the net for some vector or thematic maps of the damage assessment for download. Everything seems to be displayed by pdf or hosted through an IMS service or GE.
The imagery service has been outstanding...but the vector downloads have been non-existant. I've been actually very frustrated visiting many sites hosting GIS data and only finding images.

How about making it a network link so people who are seriously interested don't have to download a new KMZ when you get new data? Make sure you put the date of the assessment in the Key...

The Legend Key image file is missing.