The diversion of water from the Lake Michigan watershed is of major importance to the Great Lakes states and to the Canadian province of Ontario. The states and province that border the Great Lakes have concerns with both diversions during periods of low lake levels, as well as the long term effects of diversion. To insure that the concerns of these interested parties are considered, the U. S. Army Corps of Engineers has been given the responsibility for the accounting of flow that is diverted from the Lake Michigan watershed.
An annual report is traditionally published once a year. The annual report will usually contain a diversion accounting report for one or more of the previous years, depending on when the diversion accounting data was ready to be reported. In addition to the annual report, a technical committee report is also published every 5 years.
The Corps of Engineers, Chicago District, is currently responsible for monitoring the measurements and the computation of the diversion of Lake Michigan water by the State of Illinois. In the past, other agencies have been responsible for this task; as a result, some of the reports presented on this website were not prepared by the Corps. For example: