An ecological evaluation of an urban stream restoration in West Chicago, Illinois

The consistent rise in urban population and expansion of urban centers in the United States over the last several decades has led to the need for preservation of natural resources in those areas, as well as degradation to those resources. Streams in urban systems are often highly degraded and may require restoration to mitigate negative effects of urbanization and restore ecosystem function. In this study, I analyzed the physical habitat, water quality, macroinvertebrate community, and fish community of a 13 km stream restoration on the West Branch of the DuPage in the suburban Chicagoland area, using the similar, unrestored East Branch of the DuPage as a reference. The restored West Branch had higher quality instream habitat than the East Branch, especially in regards to substrate, channel morphology, and pool and riffle quality. Water quality did not vary between the streams except for flow, which was higher on the West Branch. The macroinvertebrate community on the restored West Branch was more diverse, and included more sensitive species, and scored better on macroinvertebrate community metrics designed to indicate water quality. The fish communities did not differ between the streams; however, Smallmouth Bass (Micropterus dolomieu) were found in significantly higher numbers on the West Branch. My study indicates that there were some positive effects of the restoration, but also that pre- and post-restoration data together would allow for deeper insights into the effects of urban stream restoration