years. Lakes Depue, Chautauqua, and Meredosia will be completely 

 filled within 100 years according to the Illinois State Water Survey 

 (Lee, 1976: 6; Lee, Stall, and Butts, 1976: 7). Increased sedimentation, 

 primarily from agricultural intensification of land use, and turbidity 

 have been major factors responsible for degrading backwater areas in 

 Pools 24, 25, and 26 on the Mississippi River and Pool 26 on the 

 Illinois River. Impounding Pools 24 , 25, and 26 increased the water 

 surface area, but in the ensuing years, sedimentation has filled in 

 appreciable acreage that has returned to wooded vegetation. 



150 



