FEMA Releases New Flood Elevation Maps (MS)

[struggle4progress]

<snip> Analysts have decided that the old flood elevation levels were 3 to 8 feet too low in the three coastal counties of Hancock, Harrison and Jackson, a FEMA statement said. <snip>

http://www.wlox.com/Global/story.asp?S=3952252&nav=6DJI

[DemoTex]

1. I don't understand.

Is this a CYA move or a "we fucked up" move.

[The River]

3. No, not at all

I work with these maps on a daily basis.
The maps in my area have just been updated
for 2005. The last revision was nearly 20
years ago.
These are done on a county by county basis.
Counties adjacent to mine are still using 10-15-20
year old maps.
In areas where there is a lot of development the rainwater
run-off factor goes way up, changing the amount of water streams
and rivers normally carry. This causes the flood elevation to rise
over time. These maps keep people from building in flood prone areas.

I would bet that this is pure coincidence. What was the issue
date of the last batch of maps? I bet they are a few decades old.

[DemoTex]

4. Paving, increased runoff, etc.?

BTW: Welcome home and welcome to DU!

[The River]

6. Exactly....

"Pave Paradise and put up a parking lot"
(and flood everyone downstream)

Thanks Bro'...You too

[Lisa]

7. and a more rapid peak too, I'd bet ...

I've seen hydrographs from urbanized and non-urbanized watersheds. Higher and more frequent floods with less warning time seem to be the norm, the more paving there is.

Welcome to DU, The River!

[Gregorian]

2. NOLA is just one of several...

Correct me if I'm wrong, but DC and Lower Manhattan are both vulnerable. Ie., below sea level.


Talk about two big sitting ducks waiting to happen.

[The River]

5. DC is about 20 to 30'+ above sea level

30' at Washington Monument
Is used to be marshland but never
prone to flooding from the ocean.

[Gregorian]

8. My error. I am thinking global warming. Not hurricane damage.

[The River]

9. If All the Ice Melts re: global warming

at both poles, Greenland ice sheet, etc...
half of all costal states would be underwater.
Florida would be gone.
No NYC, No DC.
The mid-west would become a vast inland sea.
Almost "Waterworld" but not quite.
Invest in mountain tops for your great grandkids.