The Chicago Area Waterway System (CAWS) is the only continuous connection between the Great Lakes and Mississippi River basins and poses the greatest potential risk for the transfer of aquatic nuisance species.
The Electric Barriers are located near Romeoville, Illinois, in the Chicago Sanitary and Ship Canal (CSSC) within the CAWS. The CSSC is a man-made hydrologic connection between the Great Lakes and Mississippi River basins that was completed in the early 20th century to address sanitation and flooding. Construction of the CSSC allowed the reversal of the flow direction in the Chicago River and accommodated increased shipping.
The Electric Barriers are operated to deter the inter-basin establishment of Asian carp and other fish via the CSSC by maintaining an electric field in the water. The barriers are one control technology in a broad interagency Asian carp prevention effort. They are formed of steel electrodes that are secured to the bottom of the CSSC. The electrodes are connected to a raceway, consisting of electrical connections to a control building. Equipment in the control building generates direct current (DC) pulses through the electrodes, creating an electric field in the water that discourages fish from crossing. Laboratory and tagged-fish study results show that the electric barriers are an effective fish deterrent.
See photos from the Electric Dispersal Barrier on our Flickr page.
A demonstration dispersal barrier (Barrier I) has been operating since 2002. A more permanent dispersal barrier was constructed in two segments, Barriers IIA and IIB, which began full-time operation in 2009 and 2011, respectively. Construction of a more permanent Barrier I, which will include two new electrodes arrays and the original demonstration barrier with upgrades, is underway. The northern new array, known as Barrier 1 North, was activated in February 2021. The original Barrier I, now known as Barrier 1 Demonstration, has had its electrodes and control systems replaced. The second new array, Barrier 1 South, is scheduled to be completed in 2023. Each barrier built takes lessons learned from the previous ones to ensure the most effective deterrence tool possible.
Effective operation of the barriers is dependent on a proper combination of frequency, length (duration) and amplitude (voltage) of the DC pulses. The Demonstration Barrier operates at a maximum in-water field strength at the water surface of 1 volt/inch with pulse parameters of 5 hertz (pulses per second), 4 ms (pulse duration in milliseconds). The other barriers currently operate at 2.3 volts/inch, 34 Hz, 2.3 ms.
The barriers are complex electrical and mechanical systems and must periodically be powered down for maintenance. Therefore, more than one barrier is needed so at least one can be active at any time.
Electric Barrier Parasitic Structures:
Parasitic structures are structural steel shapes and woven-wire rope placed strategically in the CSSC to limit the extent of the electric fields generated by the barriers to the areas designed for fish deterrence.
Installation of parasitic structure
Through partnership with the U.S. Coast Guard and the Invasive Carp Regional Coordinating Committee, the Corps remains committed to operating the barriers as safely as possible.
Occasionally, there are waterway restrictions within the CSSC due to maintenance operations of the barriers. View the U.S. Coast Guard waterway notices.