cherryblossom
09-18-2009, 11:55 PM
Racial injustices....worse than Katrina >>
When Weather Changed History: 1927 Flood (http://www.weather.com/multimedia/videoplayer.html?from=email&bcpid=823503751&bclid=1344511087&bctid=1448130634)
National Geographic
http://news.nationalgeographic.com/news/2001/05/0501_river4.html
The Greatest Flood in History
In the winter of 1926-27 the rains were so heavy that on the tributaries of the Mississippi the water had overflowed the banks, causing floods to the west in Oklahoma and Kansas, to the east in Illinois and Kentucky.
On Good Friday, April 15, 1927, the Memphis Commercial Appeal warned: "The roaring Mississippi River, bank and levee full from St. Louis to New Orleans, is believed to be on its mightiest rampage...All along the Mississippi considerable fear is felt over the prospects for the greatest flood in history."
That Good Friday morning, the rains came, setting all-time records for their breadth and intensity. They came down over several hundred thousand square miles, covering much or all of the states of Missouri, Illinois, Arkansas, Mississippi, Texas, and Louisiana.
In New Orleans in 18 hours there were 15 inches of rain—the greatest ever known there. The river swelled so high and flowed so fast that in Berry's woods, for the residents along the river, " It was like facing an angry, dark ocean."
One man recalled, decades later, "I saw a whole tree just disappear, sucked under by the current, then saw it shoot up, it must have been a hundred yards [downstream]. Looked like a missile fired by a submarine."
In the spring of 1927, the U.S. Army Corps of Engineers assured the public that the levees would hold. The Corps had built them, after all. But as had been the case at the mouth of the river, the Corps overestimated its own prowress and underestimated the power of the river.
The Corps built the levee system to confine the river. They represented man's power over nature. If necessary, it was thought, the flow would be reduced with outlets that would divert part of the river into the biggest outlet of all, the Atchafalaya River, into the Gulf, or at Bonnet Carre, just above New Orleans, into Lake Pontchartrain and then to the Gulf.
Neither levees or outlets would work, according to James Buchanan Eads, the man who built the first railroad bridge over the Mississippi, at St. Louis, and the jetties at the river's mouth (in 1932 Deans of the American Colleges of Engineering named him one of the five greatest engineers of all time, ranking him with, among others, Leonardo DaVinci and Thomas Edison.)
At South Pass, at the mouth of the river, Eads had made the river obey his will. To prevent floods he proposed cut-offs to straighten and speed the river. The increased speed could scour the bed, even during lower water. The concentration of the river's force would lower the bed so the river would carry more water, faster. By such correction, Eads declared, "floods can be permanently lowered," which would render levees superfluous.
But no cut-offs were dug. Nor was another idea, to build reservoirs on the tributaries to hold back the water. Nor were any outlets dug. The Corps of Engineers--and then the residents of the Valley--relied on levees only.
At high water the river spread and rose even higher. In turn, the Corps raised the height of the levees, from two feet to 7.5 feet to as much as 38 feet. The Corps was confident that its levees-only system would hold in the river, and it so promised.
The levees failed. Here, there, sometimes it seemed everywhere, the river undercut the levees. Water poured through breaks called crevasses, covering with 30 feet of water land where nearly one million people lived.
Twenty-seven thousand square miles were inundated. This was about equal to the combined size of Massachusetts, Connecticut, New Hampshire, and Vermont. By July 1, even as the flood began to recede, 1.5 million acres were under water. The river was 70 miles wide.
When Weather Changed History: 1927 Flood (http://www.weather.com/multimedia/videoplayer.html?from=email&bcpid=823503751&bclid=1344511087&bctid=1448130634)
National Geographic
http://news.nationalgeographic.com/news/2001/05/0501_river4.html
The Greatest Flood in History
In the winter of 1926-27 the rains were so heavy that on the tributaries of the Mississippi the water had overflowed the banks, causing floods to the west in Oklahoma and Kansas, to the east in Illinois and Kentucky.
On Good Friday, April 15, 1927, the Memphis Commercial Appeal warned: "The roaring Mississippi River, bank and levee full from St. Louis to New Orleans, is believed to be on its mightiest rampage...All along the Mississippi considerable fear is felt over the prospects for the greatest flood in history."
That Good Friday morning, the rains came, setting all-time records for their breadth and intensity. They came down over several hundred thousand square miles, covering much or all of the states of Missouri, Illinois, Arkansas, Mississippi, Texas, and Louisiana.
In New Orleans in 18 hours there were 15 inches of rain—the greatest ever known there. The river swelled so high and flowed so fast that in Berry's woods, for the residents along the river, " It was like facing an angry, dark ocean."
One man recalled, decades later, "I saw a whole tree just disappear, sucked under by the current, then saw it shoot up, it must have been a hundred yards [downstream]. Looked like a missile fired by a submarine."
In the spring of 1927, the U.S. Army Corps of Engineers assured the public that the levees would hold. The Corps had built them, after all. But as had been the case at the mouth of the river, the Corps overestimated its own prowress and underestimated the power of the river.
The Corps built the levee system to confine the river. They represented man's power over nature. If necessary, it was thought, the flow would be reduced with outlets that would divert part of the river into the biggest outlet of all, the Atchafalaya River, into the Gulf, or at Bonnet Carre, just above New Orleans, into Lake Pontchartrain and then to the Gulf.
Neither levees or outlets would work, according to James Buchanan Eads, the man who built the first railroad bridge over the Mississippi, at St. Louis, and the jetties at the river's mouth (in 1932 Deans of the American Colleges of Engineering named him one of the five greatest engineers of all time, ranking him with, among others, Leonardo DaVinci and Thomas Edison.)
At South Pass, at the mouth of the river, Eads had made the river obey his will. To prevent floods he proposed cut-offs to straighten and speed the river. The increased speed could scour the bed, even during lower water. The concentration of the river's force would lower the bed so the river would carry more water, faster. By such correction, Eads declared, "floods can be permanently lowered," which would render levees superfluous.
But no cut-offs were dug. Nor was another idea, to build reservoirs on the tributaries to hold back the water. Nor were any outlets dug. The Corps of Engineers--and then the residents of the Valley--relied on levees only.
At high water the river spread and rose even higher. In turn, the Corps raised the height of the levees, from two feet to 7.5 feet to as much as 38 feet. The Corps was confident that its levees-only system would hold in the river, and it so promised.
The levees failed. Here, there, sometimes it seemed everywhere, the river undercut the levees. Water poured through breaks called crevasses, covering with 30 feet of water land where nearly one million people lived.
Twenty-seven thousand square miles were inundated. This was about equal to the combined size of Massachusetts, Connecticut, New Hampshire, and Vermont. By July 1, even as the flood began to recede, 1.5 million acres were under water. The river was 70 miles wide.