Saturday, September 6, 2008

Post-Gustav Infrastructure Reconstruction

We all depend on vital infrastructure to support our lives and our way of life. As Ray put it, electricity is an anti-depressant. Let's see how we stand on the infrastructure front.


Here's the Times-Pic description of Entergy's efforts. Leaves out all the fun details. The phrase "Isle of Orleans" is once again accurate to describe New Orleans. We are now a "Power Island" isolated from the national grid. 13 out of 14 transmission lines were taken out by Gustav (most were around Baton Rouge) that provide power for New Orleans, Jefferson, and the sliver on the river all the way up to about St. Rose.

Entergy's engineers have to precisely balance the demand of the grid with the generation. They always have to be precisely in tune. You can't, for most practical purposes, store electricity. It is generated on an as-needed basis. Too little power, and you have brownouts or blackouts. Too much, and you blow the grid. The generation stations inside the island must do all this without any backup from the national grid. If they fail, all the power inside the grid will go out at once. Nobody in Orleans Parish or anywhere on the island will have grid power.

Think of it like performing a high wire act without a net, but don't fret too much. Entergy's engineers are good at what they do and right now, demand is still very low (because of all the people out of town and businesses shut down). Waterford, our main Nuke plant, was shut down ahead of Gustav as a precaution and they're working on getting it back up and running. If Waterford comes online, the Island should be secure until we're reconnected to the grid. In the meantime, it's fascinating a major US city can function independent of the grid.


Be careful about flushing your toilet in Jefferson Parish. 70% of lift stations are without power.

One of my coworkers is on loan to the Sewerage and Water Board while they fix the Katrina damage. He’s explained that New Orleans’ sewerage system works on a simple principal: shit flows downhill. There are long, gradually sloped conduits that carry effluent by gravity. There are large catch basins at the bottom and there are only around 100 lift pumps in the city. Much of the system can operate without power and it's easy to reconnect a small number of pumps.

J.P.’s system is based more on active pumping. Jefferson Parish has over 500 lift stations on the eastbank alone.

The New Orleans system is more expensive to setup, but requires FAR fewer pumps. The reason suburbs generally don’t do it is maintenance. If a line breaks, you only have to dig a shallow trench to reach the broken lines. In New Orleans, the S&WB has to dig halfway to China to reach the main lines. Look how deep some of there excavations get next time you drive by a work site.

Nobody ever cares about how the system works, until they’re knee deep in their own shit.


Looks like the oil industry got spared major damage. After Katrina, there were some modest improvements in infrastructure, but Katrina was so far off the scale, some in the industry don't consider it economical to build to withstand such a storm. That being said, the damage to the industry wasn't nearly as bad as people first feared. It was all repaired in short order.

Here's some footage from someone who rode out the storm on a Jackup moored in Port Fourchon:

It will take at least a week to get a full damage assessment from Gustav. One of the lessons learned in Katrina that surprised a lot of engineers is how much the deep currents can move and even break subsea pipelines. That was one of the hardest and most expensive things to repair after Katrina.

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