August 30, 2005

Disaster Math, long will the pumping take.

So, I got to thinking, if New Orleans is under 12 feet of water in 2 or so days, how much water is that? Can the pumps possibly drain that much? So I the math.

According to a number of site, the best number for pump capacity is 47,000 cubic feet per second, or about 22,701,000 gallons per minute. For this thought experiment, I'm assuming that the water is pumpable (ie, at the mouth of the pump). Reality won't bear that one up, but anyhow.

About 181.6 square miles, or 119,040 acres, will be submerged to a depth of 12 feet. There are 325,851.427 gallons to the acre foot, so the total water in the basin is about 465,472,246,441 gallons. Looks like a lot of water, to be sure. This amounts to about 15 straight days of pumping. Most of these conversions courtesy of Google Calculator, which actually knows Acre Feet!

The problems:

1) The pumps will not be able to run full bore, they will certainly get clogged with debris and require frequent maintenance.

2) The basin is not uniform.

3) The levees will take some time to repair.

4) The pumps will have to be powered up, and electrical power delivery will be tricky.

The solutions (pure, sci-fi speculation)

1) Maybe more pumps can be brought online..

2) Levees could maybe be fixed by sinking old single skin oil tankers filled with sand/cement and dropping those massive sandbags (3000lb ones) as filler. Fill em with quick setting cement and you're golden. Before you worry about the environmental cost, consider an entire city disintegrating into the Mississippi, that's not good for the fish at all.

3) Australian used diesel/electric locomotive engines to power their cities when they had some power delivery problems, this would be a decent way to deliver the electrical power needed for the pumps.

This of course doesn't address the vast crushing destruction that this much water will wrought.

More math:


1) The jump in the unemployment rate when these people can't go to work tomororrw.
2) The vast cost of rebuilding or,if warranted, mass relocation. (if $100,000 per family, then 250 billion, still less than Iraq, mind you.)
3) The loan defaults on the housing, and what that will mean to the home loan architecture in the united states.
4) The cost to the insurance industry almost guarantees they'll pull the same stuff they did during northridge here in California. This will bankrupt a great number of large insurance companies.
5) No more beads will be sold in New Orleans. I suspect Tampa's Ybor will become the cajunesque party capital of the US.

Sorry folks in New Orleans, my condolences, this is very sad. California welcomes you! Update: No way to get tankers into the lake.


Julio Fernandez said...

But you can add more pumps... now, the question is, you pump the water from one place, you have to put in in another... where? really long hoses out to sea?

But a better question is, can the Google home page link to Hurricane solutions like helping people find survivors and volunteer opportunities instead of just linking to a news section?

Chris DiBona said...

Maybe -you- can add mre pumps, but these aren't the 15$ submersible pumps you buy at your local hardware store.

A wrt to the home page link, I'll pass it on, but that's hardly a better question. People can better find those things on the red cross site.

Michael Bresnahan said...

more pumps, more power needed, but I don't think that's a problem, somthing they don't have either of at the moment. I would worry about the rest of the levees, since you have had a failure in part what's to say as you pump water out and remove the pressure on one side leaving the water pressue still on the other more failures won't take place. Maybe that's not an issue, I'm not an engineer by any means.

I also feel for all the people who now have to deal with this disaster, I live in Northern Wisconsin where we get tornado's every once in awhile and tons of snow in the winter but nothing to this extent or what people in Calif. deal with as far as disasters go.

Guillermo said...

According to the U.S. Census, the total population of New Orleans, LA is 484,674. See URL:

According to ABC News the total population of the New Orleans metro area is 1.3 million. See URL:

According to the U.S. Census, the U.S. average family size is 3.14. See URL:

Therefore the estimated number of families in New Orleans and environs should range from about 154,355 to about 414,013.

If each is awarded $100,000 per your suggestion then the total cost of your proposed program should range from about $15,435,500,000 to $41,401,300,000. Or from about $15.4 billion to $41.4 billion dollars.

That is a lot of money, but is far less than your estimate of $250 billion. Where did you get your numbers? They seem way off.

Even if you gave $100,000 to every single resident of the New Orleans metro area the total would only be about $130,000,000,000 or $130 billion. Still short of your figure of $250 billion.

And what does Iraq have to do with the relocation of the people of New Orleans? Seems like a cheapshot and an unnecessary politicization of a tragic natural disaster to me.

Guillermo Vargas
guillermo_1 at

Chris DiBona said...

I chose the multiplier as 250k per family, assuming 500k families. Mostly due to the value of real estate. As to the Iraq are too sensitive, if we can afford Iraq, we can afford to deal with this. Cries of "Politicization!" are so lame.

Guillermo said...

In your original blog posting you wrote:

"if $100,000 per family, then 250 billion"

Well, 250 billion divided by 100,000 is 2,500,000. That's simple arithmetic.

Now you say:

"I chose the multiplier as 250k per family, assuming 500k families."

That is not what you wrote in your original blog posting. But even using those numbers it is a fact that 250,000 multiplied by 500,000 is 125,000,000,000. And 125,000,000,000 is 125 billion which does not equal 250 billion. Again, simple arithmetic.

So your original numbers were wrong, as are your revised numbers.

My original comment was motivated out of a desire for accuracy and I cited the sources of my information. I was curious as to whether you had other credible sources of information that provided you with different data. It appears that you do not and that your calculations are based on pure supposition on your part.

I made my original posting on my first visit to your blog. I came here on the recommendation of the publisher of a newsletter I read, namely Chris Pirillo. Mr. Pirillo is a knowledgeable guy and I respect him and his work.

I expected to find insightful and informative commentary. Particularly since I am aware of your bona fides in the open source movement at /. and and Google. Instead I find a fellow who, when questioned about his data, changes his story and who can't do simple arithmetic. I am disappointed.

"As to the Irag thing...", you are right. If we can afford the war in Iraq then we can afford whatever it takes to help the people in New Orleans, and along the Gulf Coast, who have been dispossessed by Hurricane Katrina. I have already contributed to hurricane relief via the American Red Cross. How about you?

BTW, I am not opposed to political discussion. Feel free to ask me what I think of the war in Iraq. But I think it is unseemly to link the conflict in Iraq to the terrible human tragedy that is unfolding on the Gulf coast. Politicization of the discussion will alienate and polarize Americans when we need to be united.

And that, in my opinion, is truly lame.

Guillermo Vargas
guillermo at

Chris DiBona said...

Yes, but I find political disucssion online an enormous waste of time. As to my math, I'll check it later, it's just not that important to worry about.