THE URBAN IMPACT ON THE LITTLE CUYAHOGA RIVER, SUMMIT COUNTY, OHIO

This study assessed how changes in land use impact fluvial environments by studying channel-bed sediments of a river that flows through a major northern Ohio city. The headwaters of the Little Cuyahoga River drain a watershed dominated by rural and agricultural land uses. Flowing westward, the drainage is impounded by a series a dams at the Mogadore Reservoir. Downstream of the Mogadore Reservoir the watershed is comprised largely of residential land use. Further downstream within the city of Akron, both urban, residential, and industrial land uses dominate the watershed. Upstream of Akron, the riverbed has fine-grained sediment, the river slope is low, and the sediment trace metal (Zn, Pb, Cu, Cd, and Cr) concentrations are less than the riverbed sediment within the City of Akron. Inputs from the urban/ industrial portion of the watershed contribute to the elevated trace metal content of the sediment. A direct relationship between trace metal and magnetic mineral concentrations indicates that the rapid and inexpensive magnetic measurement may be used as a proxy for trace metal content. In addition, magnetic measurements are able to distinguish between soil and pollution particles. Within the City of Akron an actively eroding cut bank contains elevated trace metal concentrations. As this urban fill is eroded, it contributes pollution to the river at a time when new pollution inputs are being successfully controlled. Thus, urban stream management needs to assess the potential for remobilized urban fill to negatively impact the environment.