Near Norco, LA, the Army Corps of Engineers has built a 5.7-mile dam along the levee. As you can see, the Mississippi is normally well below this dam. But when a flood is coming down the river, the corps opens the dam to dump a lot of the water into Lake Pontchartrain to avoid flooding in New Orleans.
The spillway was opened in January, 2015. That was the 11th opening since it was completed in 1935. The recent openings have been 2011, 2008, and 1997. It is not opened very often because crabs, shrimp and fish leave and the crawfish and oysters die causing the commercial fisherman economic pain. Since it is not opened very often, the gates are low-tech of 20 creosoted timber "needles" in each of 350 bays. There is concern that as the climate warms, the spillway will have to be used more often. This spillway is opened when the river's flow reaches 1.25 million cubic feet per second. The Morganza Floodway above Baton Rouge is opened when the flow reaches 1.5 Mcfps and that is expected 10 days after this opening. (
NOLA)
(
Bridge Hunter)
The CN/IC mainline from Chicago to New Orleans crosses the spillway next to I-10. When the water was flowing, the tracks were shut down to regular traffic so that CN MoW people could use big back hoes and 2000 pound sand bags to shore up the trestle. A
video of water flowing under the track.
The CN trestle is wood. It caught fire at 8:30am February 13 and was contained by 2pm. So once again, the passengers on Amtrak's City of New Orleans had to disembark in Jackson, MS, and take buses to New Orleans. Fortunately for traffic on I-10, the winds were blowing the smoke away from the interstate and it remained open. The fire was started by track work. I've seen reports the cause was either sparks from rail grinding or a cut-off torch flame. The workers tried putting it out with extinguishers to no avail.
It looks like they contained it by creating a fire gap. The referenced article has several more pictures of that excavator working on the trestle.
Air boats with pumps and helicopters were used to "mop up." Note the gaps between the rails and some of the bents. Given the service interruption due to the spillway flow and the fire, maybe it is time to rebuild with concrete instead of wood.
Update:
Tom Pearson's picture and description. One of the comments observed that they were probably grinding the rails to fix problems caused by the spillway opening.
2019 Update: After rebuilding the trestle with wood in about a week [
NOLA-2016], CN has decided to replace it with a new trestle that has concrete bents. This multi-year project to replace a two-mile crossing is part of CN's $95m expenditure in Louisiana in 2019. [
GlobeNewsWire]
Erik Coleman
posted four photos with the comment: "
On a recent ride on the City of New Orleans I got a glimpse at the construction of the new replacement trestle across Bonnet Cairre Spillway near Lake Ponchartrain. One of those bridge-building bridges, quite a sight to see! Meanwhile, we are restricted to 30 mph over the mile-long ancient wooden IC trestle."
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Paul Carlson posted a video
Track and bridge Gantry Crane working on the Bonne Carre spillway crossing..
Near New Orleans... |
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