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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #177772
Title: NUMERICAL SIMULATION OF POT DAM REMOVAL SEDIMENT DYNAMICS ALONG THE KALAMAZOO RIVER BETWEEN OTSEGO AND PLAINWELL, MICHIGAN

Author
item Langendoen, Eddy
item Wells, Robert - Rob
item Simon, Andrew

Submitted to: Watershed Management Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/6/2005
Publication Date: 7/19/2005
Citation: Langendoen, E.J., Wells, R.R., Simon, A. 2005. Numerical simulation of post dam removal sediment dynamics along the Kalamazoo River between Otsego and Plainwell, Michigan. Proceedings of the American Society of Civil Engineers. 2005 Watershed Management Conference, July 19-22, 2005, Williamsburg, Virginia. 2005 CDROM.

Interpretive Summary: The state of Michigan is interested in removing four dams along the Kalamazoo River between Plainwell and Allagan. Sediment deposits behind the dams are contaminated with PCBs due to industrial waste materials. Concerns over the fate of PCB-laden channel sediments after dam removal resulted in the U.S. Geological Survey (USGS) supporting a study to evaluate the erosion, transport, and deposition of sediments in the Kalamazoo River between Plainwell and Otsego City, Michigan. Computer simulations were carried out over a 17.7-year period of record to determine the response of the Kalamazoo River between Otsego and Plainwell to: (1) removal of the Plainwell and Otsego City Dams (scenario A), and (2) a newly designed channel geometry without these dams (scenario B). Bank and bed erosion increased significantly for scenario A. The average-annual sediment load increased 34 times and the erosion of material finer than 0.01 mm increased 3 times. For scenario B, average-annual sediment load was half of that of scenario A but still 15 times greater than current conditions. This study shows that current conditions clearly provide the smallest loads for both total and fine-grained sediment transport.

Technical Abstract: The state of Michigan is interested in removing two low-head dams in an 8.8 km reach of the Kalamazoo River between Plainwell and Otsego, Michigan while minimizing impacts to the study reach and downstream reaches. The study was designed to evaluate the erosion, transport, and deposition of sediments over a 17.7-year period using the channel evolution model CONCEPTS for three simulation scenarios: Dams In, Dams Out, and Design. The total mass of sediment emanating from the channel boundary, for the Dams In case, shows net erosion of 3,350 T/y for the study reach, with net transport (suspended and bed load) of 5,010 T/y passing the downstream boundary. For the Dams Out case, net erosion jumps to 41,600 T/y with net transport of 59,200 T/y passing the downstream boundary. For the Design case, net erosion was 3,870 T/y with transport of 20,100 T/y passing the downstream boundary. The most significant findings were: (1) removal of the low-head dams will cause erosion in the study reach and increased sediment loads passing the downstream boundary, (2) bed erosion is the major source of eroded sediment, and (3) the Plainwell reach is the greatest contributor of total sediment and fine-grained sediment.