Integrated hydrologic and hydraulic modeling for the restoration of the Calumet marshes in the Great Lakes area

Lake Calumet is located south of Lake Michigan in the United States. It is a site of former landfills and abandoned industrial facilities, yet a place of economical and ecological significance for future development of the area. Marshes surrounding Lake Calumet are ecologically significant to the Black-crowned Night-Heron, but the hydrology in the area has been greatly impacted by the large amount of landfilling and the constantly changing land use and drainage of the surrounding uplands. To prevent ecosystem degradation, and recreate a local economic base, the City of Chicago Department of Environment has been leading community groups and other agencies to develop plans to restore the region to a recreational area. Millions of dollars will be invested for this effort. Hydrologic and hydraulic models have been developed to support the plan for an ecological park in the region. These models serve as a basis for determining the best water management strategies for the Lake Calumet cluster site and adjacent open spaces, known as Indian Ridge Marsh (IRM). The coupled hydrologic and hydraulic model was used to evaluate the hydrologic impacts of different remedial options proposed for the cluster site, as well as other upland properties in the marsh watersheds and to assess the adequacy of the existing marsh outlets in terms of long-range ecological goals. This paper evaluates five proposed management scenarios to cope with flooding and to establish a more suitable environment for Black-crowned Night-Heron nests in marsh areas by controlling water level fluctuations. Our study showed that diverting surface runoff from the cluster site appeared to be the best option for limiting water level fluctuations to around 8 inches in the IRM. Ten inches of fluctuation is the maximum to prevent flooding of Black-crowned Night-Heron nests in IRM.