Hydraulic retention devices in the Middle and Upper Mississippi River

Hydraulic functions of retention devices in natural large rivers have been studied. An evaluation of detention devices formed due to side channels, islands, backwaters, and stump fields within the Upper Mississippi Pools has shown that these are quite significant and in some cases these detention areas within the channel borders can occupy as much as 75 to 93% of the total surface area. A large eddy on the order of the width of the Mississippi River in Pool 19 is used to illustrate the travel time in the hydraulic retention areas.