HISTORY OF THE CHICAGO DIVERSION AND FUTURE IMPLICATIONS

The history of the Chicago diversion was analyzed to gather informatio n for assessing the potential effects and responses to global climate warming and drying in the Great Lakes basin. The mix of social, econom ic, political, and climatic factors that created a series of national and international controversies over the diversion since 1896 was defi ned and is the subject of this review. Information was gathered using a literature survey and from experts in hydrology, law, economics, and political science. The historical analysis revealed that the events c ausing controversies fell within five distinct periods. The 1845-1890 period involved attempts to solve the sewage disposal problems of a ra pidly growing Chicago. Polluted waters were being emitted into Lake Mi chigan causing a series of major typhoid epidemics, and in 1886 the ci ty decided to build a large 45-km-long canal to divert lake water and flush the city's diluted sewage into the Illinois River system. During the 1891-1930 period increasing amounts of water diverted caused four major controversies: Chicago was pitted against Missouri, the federal government, the other states around the Great Lakes, and Canada. The 1931-1956 period had a federally-forced reduction of the diversion aft er prolonged debates in the U.S. Supreme Court. Illinois frequently at tempted to get the diversion increased with controversies over each at tempt, and the build-up of navigation in the canal and Illinois River created a new need for diverted water The 1957-1978 period had a major diversion controversy which went to the Supreme Court as a result of four factors: a temporary increase in the diversion to alleviate droug ht problems in the Mississippi River basin, the growth of Chicago's su burbs and their attendant demands for lake water, the demands for wate r by the development of more hydropower plants along the lakes' exit, and the opening of the Sr. Lawrence Seaway. This controversy was resol ved in 1967, and Illinois found the Court's new guidelines unwieldy, u shering in the 1979-1994 period. The Supreme Court again handled the c ontroversy over Illinois' request to change the accounting method for the water diverted. As this period ended in 1994, yet another controve rsy was brewing over federal claims that Illinois was exceeding the al lotted diversion. The 100-year history of controversies over the Chica go diversion contains four lessons for the future. First, future socia l, economic and political forces affecting the use and control of the Great Lakes waters, both within and outside the basin, will change as both nations' political and economic worlds shift. Second, Chicago's e ver continuing growth will lead to calls for more water from the lakes . Third a major change in climate would likely reduce water levels in the lakes, produce new demands for Great Lakes water and create major diversion controversies. Finally, controversies over the Chicago diver sion, and other proposed diversions from the Great Lakes, seem a reali stic forecast for the future, with or without a change in climate.