Marcelo H. Garcia, M.T. Geoffrey Yeh Endowed Chair of Civil Engineering at Illinois and Director of the Ven Te Chow Hydrosystems Laboratory, has received a research grant from the Chicago District of US Army Corps of Engineers (USACOE) to study the impact of Lake Michigan water levels on the Chicago Area Waterway System (CAWS).
The objective of the 12-month long research project will be to analyze the impact Lake Michigan water levels have on the flow of water from Lake Michigan via the Grand Calumet River, flowing from Indiana into Illinois.
Garcia's research team had previously discovered that during the water years 2020 to 2021, when lake levels were high, water from Lake Michigan was coming into Illinois from Indiana in an uncontrolled fashion. Because of high water levels, the flow of the Grand Calumet River reversed and instead of flowing into the Lake at Indiana Harbor, it began flowing from the harbor towards the Cal-Sag channel in Chicago. Hydrodynamic modeling indicated that the flow discharge increased with lake levels and treated effluent from the wastewater treatment plants in Gary and Hammond, Indiana, was also coming towards Illinois.
The new research will investigate how much water flowed into Illinois during this time period and the potential impact it had on the Lake Michigan Diversion Accounting (LMDA), as well as flood management in the Chicago Sanitary and Ship Canal (CSSC). A consent decree by the U.S. Supreme Court dictates how much water Illinois (Chicago) can take from Lake Michigan, the amount of which is to be certified by the USACOE based on the analysis performed in this project.
The results of the study will impact water management and shed light on the bi-directional behavior of the Grand Calumet River and affect water diversion accounting processes in Lake Michigan.