"If you think it's expensive to hire a professional to do the job, wait until you hire an amateur."

"If You think it's expensive to hire a professional to do the job, wait until you hire an amateur." - Red Adair (who knew something about cleaning up expensive messes).  

Question for the Times-Pic...

TP undercuts Gill, a photo by Noladishu on Flickr.

Why are you undercutting your best Op-Ed writer off just the assertion of a spokesperson that has a reason to lie? After closing NOAH and starting to close the Mandeville looney bin, shouldn't you, you know, do research? Maybe look it up for yourself first?

Saw this at the end of this James Gill Op-Ed about Nagin.

"God help us, we're in the hands of engineers"

"God help us, we're in the hands of engineers." - Dr. Ian Malcom, Jurrassic Park.  

Somewhat related to the last engineering saying...

Engineering Sayings: "Failure is ALWAYS an Option" (H/T Mythbusters)

"Failure is ALWAYS an option"

(H/T Mythbusters)

The stylish version here.

The application to engineering practice discussed here.  

Gating the Rigolets?

This was on the cover of the paper recently:

New $1.1 billion hurricane levee proposed for New Orleans East Land Bridge 

I expected a bit better writeup on this very important project.  It's a large levee proposed stretching from New Orleans East to Slidell.  It will have gaps in the channels at the Rigolets, but will have options to install gates at a later time.  

Note that the gating of the mouth of the lake has been proposed on numerous occasions in the past.  Proposals go back at least 40 years.  It's back under discussion, partly because of Isaac's LaPlace flooding. Here's a letter to the editor shortly after Isaac calling for the gates.  

Putting in the levee along the old St. Bernard birdsfoot is a pretty low-risk, moderate-reward project.  In fact, it was even called for in the Corps' original 1962 plan for hurricane protection levees around New Orleans, but was shelved for a variety of reasons including cost.  So long as you maintain sufficient gaps for normal inflow and outflow, there's very little impact on the lake, although there's not as much of a mitigation against storm surge.  The natural tendency is to want to gate off the final gaps, but that could cause problems.  

Gates present problems risk for two main reasons: flow and backside fetch-driven-flooding.  

The first issue is flow.  Lake Pontchartrain is really more akin to a tidal mudflat than a traditional lake.  There are MASSIVE inflows and outflows in that lake on a regular basis.  Even without hurricanes, the tidal flows through the Rigolets can reach ~6-8 knots.  That's really moving.  Any gated structure will mean a choke point which will increase the flowrate much higher.  That means the structure will be very, very vulnerable to scour and undermining.  Here's an illustration of scour at the Rigolets:

Source:

McCorquodale, J. A., Georgiou, I., Retana, A. G., Barbe, D., & Guillot, M. J. (2007). Hydrodynamic Modeling of the Tidal Prism in the Pontchartrain Basin Estuary. Dept. of Civil and Environmental Engineering, University of New Orleans, New Orleans, LA.

This is a trestle bridge that supports the CSX line that runs along the Gulf Coast.  The pilings interrupt the flow and cause major scouring in the vicinity.  Note that scour very nearly destroyed the Corps-built Old River Control Structure in 1973, partly due to a design flaw:

 In 1973, a large flood tested the ORCS to its limits.  Huge scour developed underneath the large steel pilings which anchored the structure to the river bottom. The structure was almost swept away, and emergency concrete was poured into the holes as a kind of large Band-Aid.

Any gate structure in the Rigolets would have to cope with similar, powerful scour effects.  

The other problem with gating the Rigolets is backside flooding.  You'd think that if you just built a giant plug, well, that'd solve all your problems, right?  Like putting up a giant dam, no storm surge could enter and no flooding would result, right?  Not quite.  

A term used in physical oceanography is "Fetch".  Fetch describes how wind (even very weak wind) acting over a large enough surface area begins to build up waves and surge.  Isaac, despite being barely a Category 1 storm, covered a very large surface area.  Despite they eye hitting Port Fourchon, I had friends in Charleston, SC lose power from the outer bands of the storm.  Despite weak winds, they were able to act over a large area and build up a pretty impressive surge, as anyone in Braithwait or LaPlace can tell you.  

How does this relate to gating the Rigolets?  Well, let's suppose you had a continuous, 50' barrier keeping the mouth of the lake plugged up through any and all hurricanes,  you still have the surface area of Lake Pontchartrain that the wind can act upon.  The lake is ~24 miles wide by at least double that width in the other direction.  The surface area of the lake is ~630 square miles.  Even if you have a weak wind, it has enough surface area to act upon to still make a significant surge.  Even if you have gates, you'll still need levees around the edge of the lake!  Gates alone are not enough.  

Purely fetch-driven surge in Lake Pontchartrain can pile up to 6 feet+ on the Lake (Source: Ed Fleming at a presentation I attended).  Furthermore, that surge can be driven North, South, or West, depending on the direction of where the hurricane hits.  For example, a hurricane that hits Morgan City has a north-east quadrant that would drive storm surge to the Northshore.  A hurricane that hits Bay St. Louis would push surge southwards onto the lakeside levees of Jefferson and Orleans Parish.  Note that there are no Federal flood protection levees anywhere on the Northshore and, while they have been authorized for LaPlace, no funding has ever come forward to actually build them.*  Getting around to building more levees, given current rigorous standards, could be pricey.  

My main point is this is a levee project to pay particular attention to.  Especially if the gates are added later as an option.  Gates will have some tricky design challenges and are not a panacea.  

More background here from the Lake Pontchartrain Basin Foundation.

_____________________

* There was a letter to the editor by David Vitter (note: dead link) where Vitter slammed the Corps for not building the LaPlace levee that was authorized after extensive study in ~1992.  Umm... The Corps is a creature of Congress.  It does what Congress funds.  The LaPlace levee was authorized in ~1992, but wasn't funded.  Who was in charge of securing that funding?  Maybe a politician that's been there representing Louisiana for a decade plus as a Representative and Senator?

Another sidenote: We also need to kill the whole "blame New Orleans levees for Braitwhite/LaPlace flooding" thing.  This was studied and debunked before the levees were built.  They've gone back and double checked it, and sure enough, the New Orleans levee improvements had negligible effect on levees in LaPlace/Braithwhite. UPDATE- This is the link to the Corps study stating the NOLA Levee improvements had no effect.  More here: New Orleans Levees Hold, and Outsiders Want In.


UPDATE 2- I'll just add the recent Bob Marshall Op-Ed about updating the bird's foot to save the coast and help the port here.  Worth a read.

Big, Bigger, Biggest: Oil Platform

Contagion

There's a great little movie that came out a while ago called "Contagion".  It's about a modern pandemic outbreak (a la the Spanish Flu of 1919).  Turns out, the MEV-1 virus is based off a real virus:

Nipah virus is an active virus.  It's had multiple outbreaks, some with dozens of fatalities (very high mortality rate; easily communicable), and there's still no vaccine or cure today.  And it's still out there today.

Discussion of Contagion by epidemiologists 

What's interesting about epidemiology is it's a never ending battle.  You have to constantly be on your toes, because viruses mutate over time.

One of my favorite parts was where one of the scientists working on the cure talked about Dr. Barry Marshall, who drank an infectious broth to prove his theory was correct. That's a pretty amazing way to put your money where your mouth is.

Check out the movie.  Also take a look at John Barry, author of Rising Tide and The Great Influenza, writes about what's next for Swine Flu.  The Great Influenza is also worth a read.

Merry Christmas

41-0

First Saints game in person since my dad brought me when I was a little kid. Then, I got to watch the 49ers destroy the Saints.

Marques Colston is tall.
Fun game.

Rising Tide 7

Above: Rising Tide 7 Journalism Panel.

Some thoughts I want to keep and not get lost down the Tweeter tubes:

* QOTD#1: "In New Orleans, everyone has a hustle."
* The "Petri Dish" metaphor is good and applicable to both the journalism and education 'reform' initiatives.  Good job whoever came up with that one.
* Very good steering of panels.  Panel discussions were well directed and no eyes were gouged or blood was drawn.
* Great job getting more coffee early this morning.  It was sorely needed after the previous night.
* IMHO, the weakest panel was "Oil and Water".  Not a lot of new ground covered.  It could have been better and I think the parenting panel drew a lot larger crowd than they were expecting.  Also should have set out to at least discuss Bayou Corne (w/o the audience asking a question).  

* Great term: "Nuisance Complainer"
* Karnofsky and Louis Armstrong: http://t.co/jc6pdFNB
* Tulane got their butt kicked by Ole Miss http://t.co/hD5aKELV
* Here's Bob Marshall's Op-Ed about subsidence from earlier this week: http://t.co/zpfF0fuh
* Another bid issue nobody brought up is the complex litigation related to Macondo is actually limiting how much research gets published.  See here for a sample: http://t.co/G0Elc2m3
* Not mis-allocating the BP Spill money was mentioned as an afterthought.  We could have spent a panel on just that.
* Cenlamar has #standing, even when #seated.
* All this discussion about the Times-Pic is like a funeral.  I'd rather spend a little more time chatting about what The Advocate is doing.  Also, the only one with any energy is Jason, who's been up since dawn setting up and managing the webstream for Rising Tide 7.
* Nola.com writeup of the Education Panel.

Debating with my old professor.  Thanks again Susanna.  

Note: Some updates and edits.

Rising Tide 7

Schedule Here.

Storm Surge & Pumps & Albert Baldwin Wood

What it looks like, from the Corps' River Gages:

It's basically like a really, really big tidal fluctuation.  This is the lake-side of the London Ave. Canal.  

So, we've basically been dumped on and dumped on and dumped on by Isaac.  The totals are impressive (~17" at Audubon Park as of last night), but I'd say that it never really dumped all at once; it's been a slow, steady drizzle at ~0.5"/hr or less.  One interesting note to pay attention to is the outfall canal pumps.  The Lens had a report up right before the storm about how a pair of pumps were out of commission.  Matt McBride has had a series of posts tracking failure after failure of these 'temporary' (decade-plus of service by the time they're retired) pumps.  

One thing I learned as an engineer while working for a large hot sauce concern in South Louisiana is how subjective runoff calculations are.  You can have 2 systems that are rated for the same 10-year rain event, but are dramatically different.  You start by assuming how much retention the land has at the start of your design-case rain (saturated soils absorb ~nil).  They you have retention ponds built (which will actually fill up over time).  Only then do you size the pumps.  A modern drainage system tends to be very dependent on retention ponds (like New Orleans East).  The system that Albert Baldwin Wood designed in the 1910's is almost exclusively pumping power.  As designed, there was virtually no retention capacity built into the system.  Over time, the S&WB has added some retention capacity in; for example, before a storm, the canal water levels (which have a certain, nominal level, just for the stability of the canal banks) are drawn down as low as possible.  There are also relatively few, much larger pumping stations in Albert Baldwin Wood's design.  The downside of this is the feeder canals are much longer and deeper, so when there's a problem, the S&WB has to dig to China to make a repair.  On the bright side, it means that it's easier to keep power supplied to fewer stations;  Jefferson Parish has something like three times the number of lift stations as Orleans Parish*.  Wood's system was a bit more expensive to construct and maintain, but a modern system basically raises a white flag after a certain amount of time (when the retention ponds are full), while Wood's system can keep chugging right along hour after hour with minimal de-rating.

Photo of pumps being pulled from a few months back.

___________________
* Source: A Goulds pump salesman told me that.  

NOTE: Some edits for spelling.

Still here...

Have power.  No TV/Internet.  Good thing there's tethered smartphones.  Most activity we've seen so far is the neighbor's chimney lost a big chunk and dropped bricks onto the sidewalk.  

Take care and stay safe.  

Isaac

Living with Water, a photo by Noladishu on Flickr.

Stay safe.

Also, here's my suggestion for a really handy piece of hurricane gear:
http://www.amazon.com/Motorola-Universal-Dual-Charging-Portable-Power/dp/B00486MH80
It keeps your cell phones topped up. It has ~80% of the charge of my Samsung stored for emergencies.