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The Count: The amount that Norco and Michoud are sinking per year

2 inches



Source: NASA/Jet Propulsion Labora- tory-Caltech

That sinking feeling: Using airborne radar data collected between 2009 and 2012, NASA determined that areas of southern Louisiana are subsiding at markedly different rates. "While the study cites many contributing factors for the regional subsidence," the study concluded, "the primary contributors were found to be groundwater pumping and dewatering (surface water pumping to lower the water table, which prevents standing water and soggy ground)."

  More bad news: "The team also observed notable subsidence in New Orleans' Upper and Lower 9th Ward, and in Metairie, where the measured ground movement could be related to water levels in the Mississippi," NASA reported. "At the Bonnet Carré Spillway east of Norco — New Orleans' last line of protection against springtime river floods overtopping the levees — research showed up to 1.6 inches (40 millimeters) a year of sinking behind the structure and up to 1.6 inches (40 millimeters) a year at nearby industrial facilities."

  To read the whole study, visit

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