Understanding how the Mississippi River responds to the operation of the Bonnet Carre' Spillway, can help us learn about potential effects of large diversions of the river. Panel A shows the bathymetry before the spillway is opened during May of 2011. Panel B shows deposition of over 21 feet in the channel immediately after the diversion was closed 42 days later. Panel C indicates that a majority of the deposited sediment moved out of the study area within one year of the event.