Documenting a stream’s sediment yield variability from the dam pool deposit provides for a better understanding of future down
stream impacts following dam removal. In this paper, we report a study to characterize the sediment that has accumulated in the Gorge Dam impoundment on PARP activity the Middle Cuyahoga River, Ohio. We report on the century-long sediment record of anthropogenic and natural changes occurring in the watershed. Furthermore, we use an impoundment-based estimate of the Middle Cuyahoga River sediment load to assess the output from the Spreadsheet Technique for Estimating Pollutant Loading (STEPL) watershed model. The close agreement between these two methods confirms the usefulness of the watershed modeling approach and best characterizes present-day conditions within the Middle Cuyahoga River. Because the Gorge Dam is under consideration for removal, determining the sediment load record is of practical importance. Once the dam is removed and the impoundment sediment trap no longer exists, the Middle Cuyahoga sediment load will be delivered to the Lower Cuyahoga River. Located in northeast Ohio, the headwaters of the Cuyahoga River flow south before the river turns north and finally discharges into Lake Erie (Fig. 1). Before emptying into Carfilzomib nmr Lake Erie, the Cuyahoga River is impeded by several dams (Fig. 1). Prior to
the construction of the Gorge Dam, the river in this reach
flowed in a gorge over shale, siltstone, and sandstone of the Cuyahoga Group and between steep cliffs of Sharon Formation (Coogan et al., 1974, Evans, 2003 and Wells, 2003). Early settlers to Ohio were drawn to the gorge by the waterpower provided by the Cuyahoga River (Hannibal and Foos, 2003). By 1854, five mill dams were present in the narrower portion of the gorge MEK inhibitor upstream of the present study area (Whitman et al., 2010, p. 20). The recreational value of the river gorge was recognized early, and several amusement parks operated between the 1870s and 1930s, attracting thousands of people daily in the warmer months (Hannibal and Foos, 2003 and Whitman et al., 2010, pp. 59–72; Vradenburg, 2012). By 1933 the amusement parks had all closed due to declining attendance, and the site became the county Gorge Metro Park (Whitman et al., 2010, pp. 59–60; Vradenburg, 2012). Beginning in 1911 and finishing in 1912, the Northern Ohio Power and Light Company constructed the Gorge Dam (Whitman et al., 2010, p. 80). The dam pool provided cooling-water storage for a coal-fired power plant and water for a hydroelectric power generating station. The dam is located at river kilometer 72.6 in present-day Gorge Metro Park, Summit County, Ohio (Fig. 1). The dam was built on Big Falls, the largest waterfall in the gorge. The 17.4-m-tall, reinforced concrete Gorge Dam is the tallest dam on the Cuyahoga River.