2019 mississippi river flood

Travis Lux / WWNO

Heavy rains in the Midwest have caused the Mississippi River to swell. To relieve pressure on local levees, the Army Corps of Engineers will begin operating the Bonnet Carre Spillway in Norco on Wednesday.

The levees near New Orleans are only built to handle water moving at 1.25 million cubic feet per second -- quick enough to fill the Superdome in about a minute, the Corps estimates. When the river gets going that fast the Corps opens the spillway, diverting some of that water into Lake Pontchartrain.