WI Mississipi Control Structures Fail in 1973?

As the winter's snow melted and new rains came in March of 1973, large parts of the lower Mississippi flooded. The Old River Control Structure managed to keep the main part of the river flowing through New Orleans, rather than through the Atchafalaya River. Slightly more rain, slightly worse management, sabotage, or many other plausible scenarios could have resulted in the structure failing. What would have happened afterwards? Once the floodwaters subsided in May would the government try to repair the damage? Was that even possible? Would New Orleans cease to be a useful port?
 

Driftless

Donor
A more localized scale Katrina?

Flood water contains a lot of mud, biological matter of all types, chemicals, you-name-it. Streets get covered in mud, washed out, undermined, etc. Foundations and any wooden or (porous)cement block structures get saturated with that contaminated water - high degree of mold follows. With undermined or washed out roads, gas mains, water mains, sewer lines are often damaged or broken (Grand Forks, ND - Flood & Fire). How do you fight a building fire when the fire trucks can't get within a kilometer of the fire? Also, electrical and phone lines back in 1973 were either pole mounted or buried - both often compromised in floods.

1973 wasn't long after the start of the first Earth Day, so environmental impact concern would be high, but not as well politically wired in. I could imagine there could have been a great public battle over how to mitigate the future flood concerns - the historic method had/has great limitations. The more you use the levee system to channelize the river, the greater the localized damage where the levee fails. Levees do fail with frequency - they're often built primarily with local soil and when that soil gets saturated, it doesn't take much to cause a collapse.
 
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Immediate impacts:
- Morgan City destroyed, over a thousand people drowned.
- All road, rail, and pipeline crossings south of the ORCS are washed out
- - Traffic has to detour hundreds of miles north via Natchez or Vicksburg.
- - Broken pipelines cause nationwide disruptions in natural gas supplies.
- The Gulf Intracoastal Waterway is closed at the Atchafalaya.

By late summer:
- Brownouts along East Coast, as peaking power becomes unavailable due to natural gas shortages.
- Ammonia fertilizer shortages (also due to natural gas shortages) ahead of fall planting.
- Old River channel is down to 1/4 of normal flow, and has to be closed to barge traffic.
- Atchafalaya channel is still much too turbulent and dangerous for navigation

By fall harvest:
- Lack of fertilizer and shipping (plus previous Soviet buying) leads to massive spike in grain prices and worldwide unrest.
- Lack of cooling water forces refinery and chemical plant shutdowns along Old River channel.
- - Shortages and price increases for all petrochemical-based products, from gasoline and diesel fuel to housepaint and insect spray.

The shortages and price spikes will play hell with the Nixon Administration's attempts at wage and price controls.
The blackouts and economic instability will probably spark riots (especially in New Orleans, where a third of the workforce has been temporarily laid off, and water rationing is in effect.

Kazmann, Raphael G. and David B. Johnson. 1980. "If The Old River Control Structure Fails?"

http://www.lwrri.lsu.edu/downloads/L...I_B12_1980.pdf
(section beginning at page 101)
 

Driftless

Donor
Another fun thing: when flood waters rise in normally low lying areas, storm sewers often back up and floodwater come up through manholes and corner drains behind the levees. It's cost prohibitive to completely protect against those "100 year" floods.
 
large amounts of new wetlands in the Atchafalaya Basin...

Morgan City is pretty much gone...I-10 blocked at the Atchafalaya River
 

BlondieBC

Banned
As the winter's snow melted and new rains came in March of 1973, large parts of the lower Mississippi flooded. The Old River Control Structure managed to keep the main part of the river flowing through New Orleans, rather than through the Atchafalaya River. Slightly more rain, slightly worse management, sabotage, or many other plausible scenarios could have resulted in the structure failing. What would have happened afterwards? Once the floodwaters subsided in May would the government try to repair the damage? Was that even possible? Would New Orleans cease to be a useful port?


You would lose the stuff down river of the breech. It is about 20K people and a big chunk of the oil support infrastructure. Once the river takes the steeper path to the sea, it will not be put back in the old channel, IMO. New Orleans would still be a useful port. The river is only about 7 feet above see level, so it would merely need to be dredge on a regular basis. And without the silt going down stream, the swamp land south of the city would sink into the sea even faster.
 
I'd think there'd be a massive effort to try to redirect the Mississippi back to the old channel, after all there's some 2 million people or so downriver in Baton Rouge and New Orleans that depend on the port-driven economy plus all the oil/gas/chemical plants on that stretch of river. Combine the disruption to those plants and to the massive amount of grain exports that are barged down the river to elevators along Cancer Alley with the oil embargo, and the economy gets ugly fast.

I don't know enough about the structure of the ORCS (or what sort of failure are we talking about) to know whether you could repair it. It's possible the Feds could throw money at it and built a massive replacement to redirect the river back to its old channel in the medium term (5-10 years) given the Mississippi's vital importance to the nation. It's certainly cheaper than recreating the same infrastructure in the Atchafalaya Basin (which is even worse to build on then the swampy areas around New Orleans). Overall, even if successful, New Orleans, Baton Rouge, and Louisiana take a huge body blow during historically salad days for them OTL. Houston will undoubtedly steal even more business from New Orleans, and Mobile likely benefits as well.

As far as the silt goes, Terrebonne Parish gets more land. I don't see too much difference in erosion vs. OTL for most of Southeast Louisiana as most of that silt is currently dumped OTL into the Gulf at the mouth of the bird's foot 60-70 miles from where it'd do New Orleans most good. It's only in the last 20-25 years the Corps has done any sort of upriver artificial river redirection in attempts to curb erosion.
 
Wow, I was literally thinking about this just the other day.

Anyway, that report mentioned earlier in this topic is probably the best scenario. It'll be an epic disaster like no other in history, with global ramifications thanks to the effects on petrochemicals/oil and food prices.

I don't know enough about the structure of the ORCS (or what sort of failure are we talking about) to know whether you could repair it. It's possible the Feds could throw money at it and built a massive replacement to redirect the river back to its old channel in the medium term (5-10 years) given the Mississippi's vital importance to the nation. It's certainly cheaper than recreating the same infrastructure in the Atchafalaya Basin (which is even worse to build on then the swampy areas around New Orleans). Overall, even if successful, New Orleans, Baton Rouge, and Louisiana take a huge body blow during historically salad days for them OTL. Houston will undoubtedly steal even more business from New Orleans, and Mobile likely benefits as well.

Is it necessarily even repairable long-run at any feasible cost? Could you really not just use a combination of the Atchafalaya Basin with a New Orleans and Baton Rouge reduced in importance (plus perhaps Houston or another Texas port or further east in Mobile perhaps)? I mean, the Mississippi wouldn't dry up from its old course, which could be turned into a canal. There's also the fact that it would make New Orleans far more vulnerable to hurricanes and storm surges in both short and long-term.
 
The petroleum refineries alone on the Old River Channel are worth ~ $250 billion. Granted, a lot of the equipment might be salvaged and moved to new sites along the Atchafalaya, but it would still be many billions in reconstruction.
 

Delta Force

Banned
Immediate impacts:
- Morgan City destroyed, over a thousand people drowned.
- All road, rail, and pipeline crossings south of the ORCS are washed out
- - Traffic has to detour hundreds of miles north via Natchez or Vicksburg.
- - Broken pipelines cause nationwide disruptions in natural gas supplies.
- The Gulf Intracoastal Waterway is closed at the Atchafalaya.

By late summer:
- Brownouts along East Coast, as peaking power becomes unavailable due to natural gas shortages.
- Ammonia fertilizer shortages (also due to natural gas shortages) ahead of fall planting.
- Old River channel is down to 1/4 of normal flow, and has to be closed to barge traffic.
- Atchafalaya channel is still much too turbulent and dangerous for navigation

By fall harvest:
- Lack of fertilizer and shipping (plus previous Soviet buying) leads to massive spike in grain prices and worldwide unrest.
- Lack of cooling water forces refinery and chemical plant shutdowns along Old River channel.
- - Shortages and price increases for all petrochemical-based products, from gasoline and diesel fuel to housepaint and insect spray.

The shortages and price spikes will play hell with the Nixon Administration's attempts at wage and price controls.
The blackouts and economic instability will probably spark riots (especially in New Orleans, where a third of the workforce has been temporarily laid off, and water rationing is in effect.

Kazmann, Raphael G. and David B. Johnson. 1980. "If The Old River Control Structure Fails?"

http://www.lwrri.lsu.edu/downloads/L...I_B12_1980.pdf
(section beginning at page 101)

Natural gas markets weren't deregulated yet, so there wasn't really a national market for it yet, especially for utilities. That's why there are so many petroleum fired home furnaces in the Northeastern United States, and why petroleum was used to produce 17.78% of the electricity consumed in the United States in 1973. Natural gas was at 18.96% and decreasing, as price controls discouraged natural gas production (leading to artificial shortages) and there was a strong desire to reserve supplies for heating use. In fact, the 1978 National Energy Act prohibited new natural gas facility construction and set a timetable to phase out existing capacity.

There are capacity margins of 25% to 30% in the United States region now, and assuming the same held true in 1973 the country would most likely experience elevated energy prices and significant pressure on coal capacity to make up the difference.

President Nixon might also be in a better position to push for more coal and nuclear capacity under Project Independence. He was already concerned with energy issues in early 1973 even before the energy crisis. There may or may not be a petroleum embargo though. The largest impact would be on the refining industry, so there would actually be a glut of crude petroleum and a shortage of refined products, in contrast to the crude petroleum shortages that have traditionally occurred. That might even lead to greater enthusiasm for a petroleum embargo from OPEC, as they will be seeing less revenue from their exports at the same time that the refiners are making windfall profits. In many cases the petroleum exporting states lacked enough capacity to refine their own petroleum and had to import the products, so the combination of lower crude prices and higher refined product prices would become even more pressing and even more aggravating.
 
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