US Army engineers are dredging the dwindling Mississippi River 24/7 and battling seawater creeping upstream toward New Orleans' drinking water

• The Mississippi River is incredibly low for the second year in a row.
• This threatens both the country's international supply chain and national drinking water access.
• Authorities are battling against Mother Nature to try to keep the freshwater flowing. 

A long stretch of drought in the Midwest has caused the Mississippi River to drop to abnormally low levels. It's the second year in a row the river has dipped so low.