Continuous Simulation of Highly Urbanized Watershed to Quantify Nutrients’ Loadings

The United States has witnessed various extreme land use changes over the years. These changes led to alterations in watersheds’ characteristics, impacting their water quality and quantity. To quantify this impact in highly urbanized watersheds such as the Chicago Metropolitan Area, it is crucial to examine the characteristics and imperviousness distribution of urban land uses and available point and non-point sources. In this paper, the effect of urban runoff and nutrient loadings to water bodies in the Chicago River Watershed resulting from level (III) detailed urban land uses is investigated. A watershed scale hydrologic and water quality simulation using BASINS/HSPF model was developed for the highly urbanized watershed. Appropriate considerations were given to the effective impervious area (EIA). The results from the five-year calibrated water quality simulation were reasonably reflected with observed data in the study area and nutrient loadings of both point and non-point sources for 44 different land uses were found. The export coefficients (EC) values obtained are site-specific depending on conditions and variables at the watershed level such as physical characteristics, land use management practices, hydro-meteorological and topographical data, while using a continuous simulation approach and watershed perspective analysis. This is the first attempt to measure and model nutrients’ loadings using detailed land use types in the Chicago River Watershed. The proposed continuous calibrated and validated model can be used in the investigation and analysis of different scenarios and possible future conditions and land utilization.

Reconciling the Chicago River for birds and people

The Chicago River’s north branch intersects multiple urban land uses, including residential, industrial, commercial, and recreational. The north branch also supports a diversity of birds exploiting a variety of resources and structures along the river as habitat. From three breeding seasons of point count surveys, I assess the breeding bird communities in four different sections, representing four different restoration or management styles. These four river sections are also very different with regards to the surrounding neighborhood demographics. These data serve as both a baseline for future studies to evaluate restoration projects along the Chicago River, and as a snapshot to compare bird diversity and community composition between these river sections given current conditions. Unsurprisingly, the section of the river with the most extensive and longest established restoration effort had the highest species richness (number of species) of native birds. In terms of aquatic and riparian birds, however, that section was comparable to river sections with much less management in measures of both species richness and species composition. I discuss ways that river restoration efforts can be sensitive to demographic context, to avoid contributing to eco-gentrification and displacement.

The Effectiveness of an Artificial Floating Wetland to Remove Nutrients in an Urban Stream: A Pilot-Study in the Chicago River, Chicago, IL USA

Ever expanding urbanized landscapes are increasingly impacting streams that run through them. Among other stressors, urban streams often are host to elevated concentrations of nutrients, salts, and heavy metals. The pollutants, coupled with high temperatures, are drivers of ecosystem degradation in urban streams. The installation of artificial floating wetlands (AFWs) has been successful in mitigating the effects of urbanization in lakes and wastewater treatment ponds, but rarely have they been tested in streams. This pilot-study examined the ability of an AFW to improve water quality in an urban stream. The small, 90 m2 AFW was installed to improve the aquatic habitat and aesthetics of a small section of the Chicago River, Chicago, IL USA. Water samples and in-situ measurements were collected from the surface and at 0.3 m depth of upstream and downstream of the AFW. Samples were analyzed for nitrate-as-nitrogen, phosphate, chloride, and heavy metals. Comparison of upstream and downstream waters showed that the AFW lowered the concentrations of nitrate-as-nitrogen and phosphate during the growing season by 6.9% and 6.0%, respectively. Nitrate was also removed during the dormant season; however, phosphate was not removed during that time. Plant or microbial uptake of the nutrients are believed to be the dominant mechanisms in the growing season with denitrification serving as the primary pathway in the dormant season. Despite not having a measurable effect on the water temperature, the AFW was an effective means to reduce concentrations of nitrate and phosphorus, decreasing the potential for eutrophication.

Reversing the Chicago River

This chapter looks at the Chicago River and its effect on the lakefront. The chapter investigates how efforts to combat pollution in the river had the effect of cleaning up the water along the lakefront. It demonstrates how the lakefront ceased to be seen as a conduit for commerce — or as a repository for garbage and waste — and came to be regarded as an environmental and recreational amenity. The chapter then shifts to discuss the Chicago River's expansion. It details the obvious implications of the plan to reverse the river, sending sewage through the new canal into the Des Plaines River (whence to the Illinois River), for Illinois communities downstream from Chicago, such as Joliet and Peoria. The chapter also talks about the creation of the sanitary district at the close of the nineteenth century. It illustrates how the opening of the canal and the river's reversal produced an equally dramatic improvement in the quality of the water in the lake bordering Chicago. Ultimately, the chapter evaluates the challenges on the “Chicago diversion” of the waters of Lake Michigan and an endless stream of attempts to resolve the water diversion controversy.

Chicago Wetlands Shrank by 40% During the 20th Century

A team of graduate students measured wetland and biodiversity changes during the 100 years following the reversal of the Chicago River.