Impacts of Commercial Navigation on Water Quality in the Illinois River Channel

The U.S. Army Corps of Engineers shot down the navigation locks at the LaGrange and Peoria damson the Illinois River for repairs for 58 days daring summer 1987, which prevented commercial tows from traversing a 151-mile reach of the waterway. A study was designed to collect water quality and benthic data from the main channel during a30-day preshutdo wn period, during the shutdown period, and again during a30-day postshutdown period. Statistical tests were used to determine whether water quality conditions improved in the absence of commercial navigation. The results indicated that, at the present rate, commercial traffic does not significantly change overall water and benthic sediment quality in the channel.Ope