For us landlocked peeps-- difference between levee & floodwalls?

[chalky]

Inquiring minds want to know.

[NMDemDist2]

1. IIRC floodwalls only come down (or go up) when there are flood waters

present or expected

levees hold water all the time (think mini dams) usually along a watercourse such as a river and can be miles long

[NRaleighLiberal]

2. You might get an answer, but it is only a detail - don't let them...

confuse you with the detail....keep focused on the big picture, the big failure in leadership...where does the buck stop????

[ayeshahaqqiqa]

3. When I lived on the lower Ohio River

the levees were earthen walls that protected the town from the river. The floodwalls were concrete barriers that were put into place in gaps in the levees when the river flooded. The gaps in the levees were there to gain access to the river for boats and picnic areas. Hope this helps.

[BootinUp]

4. wiki encylopedia page for levee...

http://en.wikipedia.org/wiki/Levee

[ohio_liberal]

5. The levees were earthen

The floodwalls were 2ft thick concrete that ran along the top to hold back floodwaters. Apparently the media is saying they failed, not the levees.

edited for clarity

[ret5hd]

6. levee is a thick, wide long earthen berm...

designed to hold the everyday waters, and even heavy stuff up to a point.

the floodwalls are on top of the levees, a few feet higher, about 2 ft thick, designed to hold up to a CAT3 (i think) hurricane's waters.

[chalky]

7. Thanks, guys!

n/t

[Catchawave]

10. thank you for asking !

I learned quite a bit too! I'm near the Atlantic Ocean, all I know about is jettys, bulkheads and sand dunes :) Which all are worth crap during a Cat 1 here :hi:

[BeFree]

8. The above posts explain the differences very well

Interesting when talking about Categories of hurricanes. The catgories for hurricanes are based on windspeed. Wind has very little to do with floodwalls or levees.

The rating on levees should be based on rainfall in a given area. I don't know how much rainfall occured but I suspect it wasn't a horrendous amount. Katrina passed through fairly quickily. I would guess no more than 5 inches of rain fell in a 24 hour period.

More on windspeed. A storm surge would have been pushed up by the winds, leading to an overtopping of the levees, so windspeed could have been a factor, indeed.

However, it would surprise me if the New Orleans levees didn't have some kind of relief gate built in the floodwall designed to release storm surge water, keeping the whole levee from being washed out.

[cally]

9. As an aside, California has miles of levees that need repairing

I suspect many other areas do also. The ones in our delta near Sacramento and down to the SF Bay Area were built by farmers about 100 years ago. They've held up thus far, but most worry about them in major floods and during an earthquake. There have been some levee reinforcment. I would assume this is true of most regions.

[Catchawave]

11. Yikes, reminds me of the time I was evacuated from a

beach campsite for a tsunami in California! Which never came, thank goodness.