Lost Island Lake

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Project description

Smith-Root worked with Iowa Department of Natural Resources (DNR) to deter the movement of invasive common carp from Lost Island Lake into Blue Wing Marsh. At the marsh outlet, the primary direction of flow is from the marsh to the lake, but at times wind loading causes reverse flow at this location.

Together with DNR, Smith-Root designed an innovative solution to carp migration. A Graduated Field Fish Barrier was designed for a single cell concrete box culvert, and a physical barrier in the form of a vertical screen debris rack is installed on the marsh side. A state-of-the-art Acoustic Doppler Current Profiler (ADCP) was deployed on the floor of the culvert in a specially-designed protective cover. If the ADCP measures reverse flow in the culvert, the barrier electronic equipment sends a warning message to DNR operators who will lower the debris rack, reducing the risk of fish being accidentally carried through the culvert by the flow.