Lake' Chicippi' - Mississippi Flood Release Valve, Replenishment of Lake Michigan, Water Cleaning, Transportation, Recreation and Climatic Effects

Some or all of the aforementioned uses coalesced within my mind into this perhaps less than absolutely extravagant idea, which, at present, involves a flood gate, from somewhere suitably upstream from the Chicago region along the Mississippi, which would allow water from the Mississippi to flow into that area west, northwest (even southwest?) of the city, into a man-made lake fashioned to make advantageous use of existing topography/terrain to create volume and area which would provide additional water-mediated climatic moderation to the Chicago metro-region which could bolster the potential of the area to hold higher densities of person without compromising efficiency or health greatly, while creating a park-like oasis which might be used for recreational purposes, and releasing water to a chemical processing plant which might then release it along, even a canal system (:designed to keep the entire region from getting too soggy a la Venice), in order to replenish lake Michigan, since its water is drained from the lake to the Mississippi for the purpose of carrying the cities waste to the Gulf...
Thus, the canal system would be a related project.
The aqueduct project could be an element of this project, but though, similar, was slightly different in that it proposed carrying the water aloft for a longer amount of time, and was more about delivering this flow to the city of Chicago for purposes such as pools, fountains, man-made lakes, as well as replenishing the lake which is being depleted as UrbanLab drew my attention to, in their future of Chicago 2020? project.
Again, It's easier to imagine all this than to actually accomplish it: granted.