Wisconsin v. Illinois
Headline: Court enjoins Illinois and Chicago sanitary authorities from excessive Lake Michigan withdrawals, orders staged cuts, sewage-treatment work, and regular reports to protect other states’ water levels and navigation.
Holding: The Court ruled that Illinois and the Sanitary District must stop their unlawful diversion of Lake Michigan water and comply with staged limits, reporting, and sewage-treatment measures set by the Court.
- Requires staged reductions in Lake Michigan water diverted by Illinois and Chicago.
- Forces construction and operation of major sewage treatment works and semi-annual reports.
- Allows a small ongoing outflow for navigation after treatment is in place.
Summary
Background
The dispute involves the State of Illinois and the Sanitary District of Chicago, which have been diverting large amounts of water from Lake Michigan into the Chicago Drainage Canal to dilute and carry away Chicago’s sewage. Other states that rely on the Great Lakes sued, saying the diversion lowered lake levels and caused them great losses. An earlier decision in this suit found the diversion unlawful and sent the case back for a plan and timetable to restore the complainants’ rights without creating public health or navigation disasters.
Reasoning
A master reviewed detailed plans and recommended step-by-step reductions in the diverted flow combined with major sewage-treatment works. The Court approved those recommendations within limits. The decree enjoins diversions above specified annual averages: beginning July 1, 1930, a limit of 6,500 cubic feet per second in addition to domestic pumpage; by December 31, 1935, a limit of 5,000 cfs; and by December 31, 1938, a limit of 1,500 cfs. The Court required construction and approval of control works (with Secretary of War involvement), accepted estimates that treatment would remove roughly 85–90% of pollutants, and rejected overly broad demands like fully closing the Lockport outlet.
Real world impact
Practically, Illinois and the Sanitary District must build and operate major sewage-treatment and control works, follow a staged schedule to cut diversions, and file semi-annual progress reports with the Court starting July 1, 1930. The Court kept jurisdiction to modify the decree and noted that Congress could act later; costs are to be paid by the defendants.
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