Rescuing farmland after a flood @physorg_com

Posted on January 14, 2015 By

The Bird's Point-New Madridf Floodway is designed to divert 550,000 cu ft/s (16,000 m3/s) from the Mississippi River during the "project design flood" hypothetical flood event. At this flow the level of the Mississippi River will drop 7 feet (2.1 m) at Cairo. Unlike the Morganza and Bonnet Carre Spillways in Louisiana, the Birds Point-New Madrid Floodway does not have floodgates. The floodway is operated by a controlled destruction of the levee, either with explosives or by overtopping. The frontline levee has an 11 miles (18 km) fuseplug section of the upper levee and a 5 miles (8.0 km) section at the lower levee that are lower than adjacent sections. The operation of the floodway is directed by the president of the Mississippi River Commission after consultation with the Chief of Engineers.

The Bird’s Point-New Madridf Floodway is designed to divert 550,000 cu ft/s (16,000 m3/s) from the Mississippi River during the “project design flood” hypothetical flood event. At this flow the level of the Mississippi River will drop 7 feet (2.1 m) at Cairo. Unlike the Morganza and Bonnet Carre Spillways in Louisiana, the Birds Point-New Madrid Floodway does not have floodgates. The floodway is operated by a controlled destruction of the levee, either with explosives or by overtopping. The frontline levee has an 11 miles (18 km) fuseplug section of the upper levee and a 5 miles (8.0 km) section at the lower levee that are lower than adjacent sections. The operation of the floodway is directed by the president of the Mississippi River Commission after consultation with the Chief of Engineers.

We followed this flood event as keenly as anyone else with a stake in it, watching the two largest river systems, the MS & MO, unload  on the Upper MS River in 2011.  I found it amazing how those levees were designed to be blown or overtopped should just such a scenario arise. What forethought by the Corps of Engineers. Yet, now we are seeing the follow-up studies, and finding many things that should be in place before the river gives us such a grim choice when the next major flood event comes.  ~Bruce Biles

When levees fail, either naturally or as an intentional breach, as was the case on the Mississippi River in 2011, an orchestrated effort is made to remove or repair flood-damaged homes and other structures. A University of Illinois soil scientist believes that an equivalent effort should be coordinated to assess soil damages, including how flooding has affected soil productivity and land used for agriculture.

The U.S. Army Corps of Engineers detonated explosives at the Birds Point levee near Wyatt, Missouri, at 10:02 p.m. on May 2, 2011. Water from the intentional breach flooded a 130,000-acre stretch of land. Two more breaches were detonated on May 3 and 5. This image from the Advanced Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft shows the resultant flooding of farmland west of the Mississippi 20 miles (32 kilometers) south of the levee breach. On the image, vegetation is displayed in red, bare fields in gray and water in blue. The image covers an area of 30.7 by 39 miles (49.5 by 63 kilometers), and is located near 36.5 degrees north latitude, 89.4 degrees west longitude.  Courtesy of NASA and Wikipedia.

The U.S. Army Corps of Engineers detonated explosives at the Birds Point levee near Wyatt, Missouri, at 10:02 p.m. on May 2, 2011. Water from the intentional breach flooded a 130,000-acre stretch of land. Two more breaches were detonated on May 3 and 5. This image from the Advanced Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA’s Terra spacecraft shows the resultant flooding of farmland west of the Mississippi 20 miles (32 kilometers) south of the levee breach. On the image, vegetation is displayed in red, bare fields in gray and water in blue. The image covers an area of 30.7 by 39 miles (49.5 by 63 kilometers), and is located near 36.5 degrees north latitude, 89.4 degrees west longitude. Courtesy of NASA and Wikipedia.

“The United States Army Corps of Engineers, the Mississippi River Commission, and the USDA Natural Resource Conservation Service should develop an agreement to immediately update the survey maps, conduct a land scouring and deposition survey (commonly done now by USDA, NRCS), and create a soil conservation plan to ensure a rapid federal response after every levee breach and subsequent flooding event,” said Ken Olson. “This should be part of the federal government emergency response to a natural disaster. Disaster and emergency relief funds are now being used for restoration and repair work, including opening drainage and road ditches by removing sediment, levee repairs, crater lake filling, restoration of land-scoured areas adjacent to the levee breaches, and sand deposit removal from fields next to the crater lakes.”

Obrian-Bird-NewMadridOlson led a team of scientists in a study of a 195-acre O’Bryan Ridge gully field area in Missouri and found that the area suffered a permanent loss of 30 percent of its agricultural productive capacity. Read more at Physics.org.

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