Scott E. Castelli, (Scott.Castelli@diamondcluster.com)

and

Aaron A. Jennings, Professor (aaj2@po.cwru.edu)

Department of Civil Engineering

Case Western Reserve University

Cleveland, OH 44106-7201

Lower Shaker Lake is a small, highly impacted man-made like in the Doan Brook watershed of Cleveland, Ohio. The lake is a historic feature of this small watershed. It was originally constructed by Shakers in 1829 and is probably the oldest man-made lake in Ohio. It is highly valued for its aesthetic and environmental value to the urban residential communities that have grown up around it. Lower Shaker Lake is also highly impacted by sediments and urban stormwater runoff that may still include combined sewer overflows. This yields poor water quality and the accumulation of sediments. Fear that the lake was "rapidly filling in" with sediment led to a dredging proposal. This, and an unusual series of events produced a proposal for "dredging" the lake as a "dry-dredging" operation that required draining the lake and drying the sediments so they could be removed by excavation.

This poster presentation depicts results of a baseline survey that was conducted to document conditions within the lake prior to the draining/drying/dredging event. Results are presented that indicate that the proposed dredging project (limited scope dry dredging) was neither feasible nor necessary. Although the project was attempted (the lake was drained), little sediment was ever removed. A lakebed topographical survey revealed a distinct channel structure that did not survive the draining event because the unstable sediments "slumped" into the submerged channel. Laboratory sediment drying experiments indicated that it was unlikely that the lake sediments could dry sufficiently to be removed as proposed. Adequate drying would have taken at least 1-2 years. Laboratory testing also indicated that changes in physical properties of the un-removed sediments might have armored them against future scour. A companion poster presents the results of additional modeling and laboratory experimentation that was conducted to predict the consequences that these unintended changes may have on the future of Lower Shaker Lake.