New Orleans: Breach closed in 17th Street Canal levee

Times Picayune ^ | Sept. 4, 2005 7:32 p.m. | joe darby

[okstate]

The toxic water will be a major problem but I don't think there's really any other option for dealing with it right now. It has to be removed from the city no matter what... and if you think about it, the lake water and New Orleans water have already mixed together so the lake is probably already polluted from the flood.

[_Jim]

The Drainage System Since 1970

By 1970, the New Orleans Drainage system consisted of

• 167 miles of open and covered canals,
• 45 miles of pipelines, and
• 14 pumping stations
• with a capacity of 28,000 cubic feet per second.

Pumping capacity reached 34,880 cfs by 1977 (The Consultant 1977:6).

The limitations of the system were revealed by the 100-year floods that occurred on May 3, 1978, and April 12, 1983 (Villarrubia 1984).

The Sewerage and Water Board developed a plan to double the city's drainage capacity to 5 inches of rainfall in five hours by the year 2041, at a projected cost of $1.8 billion (Ruth 1991).

By the mid-1980s, the New Orleans drainage system had a primary storm water collection system consisting of

• 83 miles of covered canals,
• 57 miles of large pipelines,
• 83 miles of open canals, and
• 1258 miles of subsurface drain pipes,
• served by 18 large pumping stations and three smaller stations
• with a combined capacity of 22,500,000 gallons of water per minute (Sewerage and Water Board n.d.).

Of the over one hundred pumps in New Orleans' drainage system in 1991,

48 of them are Wood designs (Ruth 1991).

In 1992, the total pumping capacity of the 22 New Orleans Drainage system pumping stations had reached

• 47,000 cubic feet per second,

and alterations and modifications to the drainage system have continued in the 1990s.

[Peach]

I see. Thanks for explaining that.

[castlebrew]

depends..AC or DC?

sorry, a straight line like just can't go untouched (yes, pun intended!)

[John Jamieson]

I've thinking about this problem all week.

I think the flooded area is less than 60 sq miles (from guesses based on simulations and satellite photos)

And, the depth varies from 0 to 8 feet at the maximum flood. The water is now down to 0 to 6 feet feet from the pictures I've seen. LP is slowly draining lowering the level.

Therefore I figure 180 sq mile feet of water or 180*640 acre feet.

Pumping station #6, the largest one, can pump 850 cu ft per sec. or about one acre foot per minute. 60 acre feet per hour. If pumping station # 6 alone is all we have it would take about 2000 hours, or 80 days.

3 times pumping station #6 would do it in 27 days.

This range is pretty well in agreement with Corps estimates of 36 to 96 days after full pumping starts.

just added:

27 days, 22,000 KW:

27*24*22,000=14,256,000 kw hours or $1,425,600

I don't think the energy cost is a big deal!

[hlmencken3]

for reference

[ImphClinton]

Pump a foot and check. Then another and another.

Better still install monitoring equipment to check for any cracks all the time.

Hey what am I saying? They know what they are doing. There will be no problems. That is why it will take a while. Better done right the first time.

[McGavin999]

Two broke. This is the 17th St Canal levee. The other one is at the lake.

[John Jamieson]

I've been thing about your problem Brush.

This basically an impedance matching problem:

If your 50 ohms, you'll get a power transfer with two 25's in series, or two 100's in parallel. Both will be equal to one 50 however.

Either way your going to suffer atleast a 6 db loss.

Good luck and be sure to fuze the circuit.

[Mike Darancette]

I don't know what Bush said to him on Air Force One

It was a real Come-To-Jesus meeting all right.

Knute Rockne would have been proud.

[Howlin]

[McGavin999]

Would it make a difference if it's not a levee?

They call it a levee so they can give the impression that the flood is because the government didn't give them the money to fix it. It's a canal inside the city that drain the water when it rains from the high points into the lakes.

[John Jamieson]

That's great. 47,000 cuft/sec is over an acre foot a second. The only number I had was pump station #6 at 850 cuft/sec.

Does the 47k apply to downtown levee area or the entire NO area?

[Mike Darancette]

You will see an imprint of that seal on Nagin's right buttock.

[George Oh Well]

You're an incredible optomist John. I hope you're right. I'll copy that $1.5 million figure and start a new thread after the pumping is done and compare it to the actual power costs of the pumping if they're available.

[John Jamieson]

No, just an engineer.

My numbers agree pretty well with Corps, that's good enough for me.

Besides, I stayed at a ..... last night.

[Vinnie]

If I were to someday end up with two women for an evening, would I connect them in series or parallel?

In series the discharge would be less, but recharge quickly.

In parallel the discharge would be much greater but recharge time considerably longer.

There ain't no free lunch.:)

[Yasotay]

bump for later

[_Jim]

The ENTIRE NOLA area; I don't a good picture as to whether they have a zoned pumping system or not either ...

[_Jim]

It's a canal inside the city that drain the water when it rains from the high points into the lakes.

Really!!???

Not part of the pumped-drainage system huh?

SO glad that is cleared up ...