1877 to 1930
This period begins in 1877 with the founding of the State Laboratory of Natural History in Normal, with Stephen Forbes as Director. There had been earlier attempts to establish scientific organizations in the state, but this is the first successful one. The founding of this and other state-supported scientific entities leads to the systematic collection of environmental data and to the examination of the effects of water pollution, first on humans, and then on the aquatic communities within the river.
This period witnesses the most devastating effects to the Illinois River, from Chicago to Grafton. As population increases, so do the amounts of human waste, and as industry expands, manufacturing wastes also grow dramatically. Their discharge into the Illinois River causes serious human health problems. The reversal of the Chicago River in 1900 to improve the city's sanitation problems adds water from Lake Michigan to dilute the effects of sewage moving downstream. But this added water in the Illinois River causes additional serious problems, so levee and drainage districts are formed - and ultimately destroy much of the floodplain.
This period ends in 1930 with the construction of sewage treatment plants to treat human wastes before they enter the river. The floodplains are largely drained, and levees are constructed with the result that few lakes and wetlands connect to the river so fisheries are greatly reduced.
