 The USACE began work on ecosystem restoration projects along the lower Missouri River in the early 21st century . Because of the low use of the shipping channel in the lower Missouri maintained by the USACE , it is now considered feasible to remove some of the levees , dikes , and wing dams that constrict the river 's flow , thus allowing it to naturally restore its banks . By 2001 , there were 87 @,@ 000 acres ( 350 km2 ) of riverside floodplain undergoing active restoration . 
 The USACE began work on ecosystem restoration projects along the lower Missouri River in the early 21st century . Because of the low use of the shipping channel in the lower Missouri maintained by the USACE , it is now considered feasible to remove some of the levees , dikes , and wing dams <a href='null_relcl' title='1'><mark>that</mark></a>constrict the river <a href='null_genetive' title='2'><mark>'s</mark></a>flow , thus allowing it to naturally restore its banks . By 2001 , <a href='dey_it' title='3'><mark>there</mark></a> <a href='uninflect' title='4'><mark>were</mark></a> 87 @,@ 000 acres ( 350 km2 ) of riverside floodplain undergoing active restoration . 
The USACE began work on ecosystem restoration projects along the lower Missouri River in the early 21st century . b/c of the low use of the shipping channel in da lower Missouri maintained by the USACE , it is now considered feasible to remove sum of the levees , dikes , and wing dams constrict tdariver  flow , thus allowing it to naturally restore its banks . By 2001 , it was 87 @,@ 000 acres ( 350 km2 ) of riverside floodplain undergoing active restoration .