Facinating info MapMaster!
Here is the NOAA high-res image that includes the KMart (as luck would have it I hit it on the first try):
For what it is worth...there does appear to be mud and debris on the roof of the KMart, although other nearby rooftops appear to be pristine.
There was that story floating around here a day or two after Katrina about a woman reporter who, supposedly on I-10, stopped at the BSL exit and the exti ramp went off into a lake. (Later note: that exit is over land that is only 5 ft above sea level).
When considering water height inland, remember that elevation is key. A water source such as the Pearl River or St Louis Bay might have been nearby. Hancock County is very shallow for a good ways inland, so being inland does not necessarily imply a higher elevation.
Well LSU measured 29 feet officially for Waveland, and then a different group in Waveland measured 30 ft. I'd sure like to know some other numbers if there are some higher than 30, because that would be the new record. It seems likely though, because Biloxi did get 30 ft, and the strong northern eye wall was centered just to the west of Waveland, with the western winds driving the storm surge parallel to shore into a dead end (the curve of land at the edge of the MS coastline) right at the Waveland / Clermont Harbor area.
I do believe the Biloxi number of 30 ft because of my brother's experience of seeing 1 ft of water at a 25 ft elevation 3.5 mi NNE of the tip of Biloxi just in from Back Bay (the St Martin substation). So it would not be at all surprising if Waveland/BSL got a higher surge.
We do know that the BSL courthouse at 30 ft had a wall eroded either by surge or by waves and debris on top of the surge.
OK at this point I'm speculating that surge coming from the GOM, meeting the surge coming inland from the bay, could have risen higher than the surge height, right at that point, for a short time, and could have washed things up onto high points such as the tops of buildings in that area. If so it would likely have been a very narrow point where the waters met, and so that might explain why one roof coiuld have been topped, but not another nearby.
The debris line from the GOM does not go in any further than the railroad tracks, for the most part, in Waveland, but it is clear that the entire area was under water to some extent because of the pools of water and the mud covering streets, etc, inland of the tracks, in the NOAA images. Remember Frank P finally found parts of his home much further in than the debris line along the GOM in Biloxi.
Note: the KMart is at a 10 foot elevation...that "14" on the topozone map is not an elevation number (there are a lot of other numbers on those maps that I don't know what they are referring to).
By the way -- having come across a lot of elevation numbers that were inflated in various stories...apparently the BSL courthouse is on Court St practically on the bay, about 500 ft from shore. Elevation maps show it is not at 30 feet as specified. It is between 20 and 25 ft, and looks to be closer to 20 ft in elevation. So I am hoping that the actual courthouse the Hancock County EOC stayed in was some other location and not the one that I found. But I think that it is the one.
Do you know what...except for a tiny little stretch of land over 25 ft nearby, there just isn't anything higher in all of BSL and Waveland; not until you get north of I-10, which is unincorporated. There were simply no structures for the Hancock County EOC or other support orgs to use except those in the city.
That is why it was absolutely critical to determine the height of the surge. They had to go by the NOLA NWS HLS (Hurricane Local Statements). Remember that 1) Katrina was forecast to hit at least 15 miles more to the west than it did, and 2) the flood forecase of 18-22ft...up to 25 ft "near and close to the center" (which was changed to a max of 28 ft only at the 5:45pm Sunday HLS) for any other hurricane in anyone else's experience certainly would not have been more than 5-10 miles to the east of the center. By the time it was determined the center was going to hit to the west of Waveland, at the MS/AL border, it was much too late to pick up the EOC and other agencies and try to move elsewhere, as winds had started picking up a couple of hours earlier.
The problem with these low-lying counties like Hancock and Jackson is that there are very few places that are above a Cat 5 surge level, and those places are inland with little development, far from the coastal cities, and even in that small-town environment are known as the backwoods or boonies area. So there are really no structures to pull back to out of the storm surge area. Sheriff's depts will have to consider rebuilding some secondary structure in these rural areas. For surges that would be at the Cat 5 level, all of the county, possibly even emergency personnel, would have to be evacuated anyway because it would end up mostly underwater like Cameron County in LA did.
Now that I've reviewed elevation height for Hancock County I can see that surge wouldn't have to be over 30 feet to cause that kind of devastation.
Edited by Margie (Thu Sep 29 2005 12:28 AM)