These pumps are so loud that people have to shout into one another's ears to be heard. When these two leaned together next to the river, it was a chance to photograph both the bubbling water and the effect of the noise. You can see an audio slide show from this situation here: http://www.msnbc.msn.com/id/25265914/

John Brecher/msnbc.com
Missouri National Guardsmen Robert Mangum and Nate Frazier talk about their water pumping operation next to the flooding Mississippi River in downtown Clarksville. Several pumps are emptying thousands of gallons of water per minute from behind the sandbag levee.