Building dikes is another way to control the river and improve navigation. The dikes are usually built near river crossings to direct the flow as it crosses from one bend to another. Also, the dikes are used to prevent a secondary channel from capturing a larger part of the river's flow, which would make the main channel inadequate for flood control and navigation. Without dikes these areas have to be dredged more often to maintain the required channel depth.
Although the dikes at Hogpoint appear to be above the river surface in this picture, they are actually below the surface.
Hogpoint above Baton Rouge, LA. Dredging
Dredging is necessary to maintain the channel depth and width for navigation. Different types of dredges (cutterhead, dustpan, hopper) are used depending upon the area.
The Corps Dredge Jadwin at work, with dredge discharge in the deeper center of the channel.
The Corps Dredge Jadwin at Philadelphia Crossing in the Mississippi River.