Civil Engineering Departmental Seminar - MODELING THE WATER QUALITY IMPACTS OF THE ECOLOGICAL SEPARATION OF THE GREAT LAKES AND MISSISSIPPI RIVER BASINS AT CHICAGO FOR INVASIVE SPECIES CONTROL

MODELING THE WATER QUALITY IMPACTS OF THE ECOLOGICAL SEPARATION OF THE GREAT LAKES AND MISSISSIPPI RIVER BASINS AT CHICAGO FOR INVASIVE SPECIES CONTROL

In 1900, the Chicago Sanitary and Ship Canal (CSSC) was opened to reverse the flow of the Chicago River diverting the wastewater from Chicago away from Chicago’s water source, Lake Michigan, and toward the Mississippi River.  This project has been a great public health success for Chicago, but in the later 20th Century the CSSC and other waterways of the Chicago Area Waterways System (CAWS) became a conduit for invasive species to move between the Great Lakes and Mississippi River basins.  The U.S. Army Corps of Engineers evaluated methods to prevent the migration of invasive species between the Great Lakes and Mississippi River basins particularly in the Chicago metropolitan area in the Great Lakes and Mississippi River Interbasin Study (GLMRIS).  The DUFLOW modeling system developed in the Netherlands has been adapted to simulate water quality in the CAWS.  This model was applied to consider Current (actual inflows in the test water years), Baseline (inflows changed to reflect facilities expected to be operational in 2017), and Future (inflows changed to reflect facilities expected to be operational in 2029) in the CAWS for no separation, lakefront separation, or mid-system separation project conditions.  This presentation discusses the changes in dissolved oxygen (DO) concentrations and in compliance with DO standards in the CAWS resulting for the various projects and flow conditions.  Three representative water years, a wet year (2008), dry year (2003), and medium year (2001), are considered to compare the DO results from no project and those resulting for the various ecological separation scenarios.  How this water quality simulation results affected the final project selection also is discussed along with the current status of the GLMRIS project.