Water Quality

The United States Fish and Wildlife Service (USFWS) release a report in December 1963 entitled, “Fish and Wildlife as Related to Water Quality of the Illinois River Basin.” This special report on the fish and wildlife resources of the Illinois River Basin examines the effects of water quality. The quality of the water in much of the length of the Illinois River is found to be within “limits considered sage for fish and wildlife.” This is not true for the “grossly polluted zone above Joliet.” Despite this, the report finds that “conditions do not meet the necessary standards for healthy maintenance of aquatic life.”

The report confirms that siltation of the flood-plain lakes near Havana results in a reduction of flood storage capacities and causes serious changes to the bottom fauna as discussed earlier. The abundance of nutrients in the water accounts for the largest amount of turbidity during summer months. The report finds that much of the “high fertility, sediment, and turbidity is [sic] the result of drainage of surrounding farmlands.”

Another source of pollution of the river is sewage discharge from local communities. Of the 257 incorporated communities in the Illinois River Basin, 69 have sewer systems and 46 additional have some type of sewage treatment. Table 21 provides the breakdown of sanitary facilities by population groups effective 1940.

Table 21: Illinois River Basin Towns and their Sewage Treatment Capabilities (Illinois State Planning Commission 1940).

Population Groups